Zenadji Sylia
email: zenadji.sylia@gmail.com

Cédric Gueguen
email: cedric.gueguen@irisa.fr

Brikh Lamine
email: blamine@outlook.fr

Talbi Larbi
email: larbi.talbi@uqo.ca

Khireddine Abdelkrim
email: abdelkrim.khired@gmail.com

Gueguen Cédric

New strategy for resource allocation using PSO-PFS hybrid

Keywords: Resource Allocation, 5G, Tri-sectoral Cell, PSO-PFS, Throughput, Fairness

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Introduction

Ensuring a real quality of service QoS in mobile multimedia transmissions is an important challenge. One of the major features of wireless networks are subject to many channel impairments (pathloss, shadowfading, multipath fading) [START_REF] Ragaleux | Adaptive and Generic Scheduling scheme for LTE/LTE-A Mobile networks[END_REF]. These phenomena severely affect the quality of service in terms of delays or packet loss, in this case the users can not benefit from the same transmission capacity. Therefore at some point a radio resource may be of good quality for one user as it may be bad for another. In this context, in recent years, researchers have paid considerable attention to the allocation of resources for digital communication networks. Among all the transmission techniques studied, Orthogonal Frequency Division Multiplexing OFDM has emerged widely for new generation transmission networks, LTE and 5G [START_REF] Gueguen | Inter-cellular scheduler for 5G wireless networks[END_REF]. On the other hand, the OFDM is an access method that allows the bandwidth to be divided into several sub-frequency bands. In addition, each carrier has a low bandwidth in relation to the total bandwidth used, which leads to a high tolerance for multipath propagation problems. In [START_REF] Parruca | Analytical Model of Proportional Fair Scheduling in Interference-limited OFDMA/LTE Networks[END_REF], the authors provide an equitable distribution of resources to fight against the impact of multipath propagation, but in return, the throughput of the system is reduced. The authors of [START_REF] Li | Intracell Cooperation and Resource Allocation in a Heterogeneous Network Relays[END_REF] proposed a resource allocation based on orthogonal frequency division multiplexing (OFDMA), assuming a complete reuse of the frequency between macrocells and microcells.

Various works have generated great interest for new Scheduling and Optimization algorithms. In the first, the opportunistic Scheduling algorithms attribute a higher priority to users with better channel conditions [START_REF] Nsiri | Modeling and Performance Evaluation of Novel Scheduling Algorithm for Downlink LTE Cellular Network[END_REF]. The research in [START_REF] Saxenal | Strategy for Ressource Allocation in LTE-A[END_REF] evaluate different strategies of resource allocation from different schedulers and conclude that performance comprehensively depend upon channel imperfection.

The inter-cellular scheduler algorithms control the resource allocation and allow intelligent distribution of the subcarriers in a cellular network. In [START_REF] Gueguen | Inter-cellular scheduler for 5G wireless networks[END_REF] propose a new intercellular Bandwidth Fair Sharing Scheduler (IBFS) able to help the overloaded cells thanks to a dynamic cell bandwidth allocation in multi-user 5G wireless networks. FFRDIBFS is proposed by [START_REF] Ezzaouia | A Dynamic Inter-cellular Bandwidth Fair Sharing scheduler for future wireless networks[END_REF] which distribute the frequencies in the overloaded cells without destroying the QOS of the underloaded cells, where the objective is to dynamically calculate the minimum bandwidth of an underloaded cell. In the second, the major advantage of using the evolutionary algorithms is the maximum exploitation and exploration of the search space to find the global optimum solution or near global optimum solution. In [START_REF] Barada | Macrocellfemtocells resource allocation with hybrid access motivational model[END_REF] a genetic algorithm is proposed for improving efficient resource allocation Macrocell-femtocell, the proposed model encourages femtocell owners to share resources with public users. A dynamic optimization of resources based on the Particle Swarm Optimization algorithm (PSO) considering the fading channel, the change of channel state of the users and the relay stations in a macro-cellular [START_REF] Li | Dynamic Optimization for Resource Allocation in Relay-Aided OFDMA Systems Under Multiservice[END_REF] has been suggested to achieve better performance in terms of throughput and equitability. The resource allocation based on PSO (Particle Swarm Optimization) and hybrid PSO-GA (Genetic Algorithm) [START_REF] Sun | Device-to devise ressource allocation in LTE-advanced networks by hybrid particle swarm optimoization and genetic algorithm[END_REF] have been proposed to maximize the throughput of the two-pair D2D communication system of the whole macro cell.

Although the quality of service (QoS) of intracellular wireless networks has improved significantly, recently several studies have been proposed studying the sectoral spectrum allocation mechanism, which improves system performance. In [START_REF] Lei | A nouvel Multi-cell OFDMA system structure using fractional frequency reuse[END_REF] a new frequency reuse scheme is proposed, the sub-carriers are divided into two groups, in the central region of the sectors, and at the edge of the three sectors. A spectrum distribution into four sub-bands and allocating those to different sectors with six directional antennas macrocell to reduce interference has been studied in [START_REF] Alitaleshi | Ameliorated Ressource Allocation in Two-tier Femtocell-Macrocell Networks with Six Directional Antennas for Macrocells[END_REF]; the results show that the utilizing six-sectors, the throughput of macrocells progressively increases. In [START_REF] Ho | Multi-carrier Cell Structures with angular Offset[END_REF] authors have proposed a sector offset configuration strategy for multi-carrier networks, the pattern offset is 60 degrees.

QoS cannot be guaranteed when the users are located in critical positions. The position of users has a direct relationship to channel conditions, and the constraint of induced path losses has an unequal spectral efficiency, typically for users in regions of sectoral overlap, causing cross-sectoral interference and a low SINR. However, for such a constraint implies an inequality in terms of throughput and fairness between different users. 5G systems should take over the design of techniques that effectively manage all spectral resources; in addition, these main objectives are to provide high throughput in the cell with low latency [START_REF] Pirinen | A brief overview of 5G Research Activities[END_REF]. The opportunistic Scheduling favors users with better channel conditions and the major concern for the scheduling discipline should be to maximize the total throughput for all users. In this context, to resolve this problem, the contributions of this paper are summarized as follows. First, we exploit frequencies in an opportunistic way, do not make a 50/50 frequency distribution in each sector of the cell but adapt it according to the position of the users and their requests. Second, in order to overcome the limitation of the Scheduler Proportional Fair in terms of throughput, we propose a hybrid PSO-PFS that can improve the performance of PFS in a tri-sectoral cell, we present and explain the concept of resource allocation in a Tri-sectoral cell, which corresponds to the amount of radio resources that can be allocated while maintaining frequency reuse1.

The remainder of this work is organized as follows. System model is presented in section 2. Scheduling algorithm strategies are given in section 3. Section 4 presents the performance evaluation results of our proposed resource allocation schemes. Finally, in section 5, we outline the conclusion of this paper and future work.

System Model and Problem Description 2.1.Channel Model

We consider a tri-sectoral cell with a base station (BS) and K mobile stations (MS) uniformly distributed in the cell, An equal frequency distribution is applied, sharing a total number of N subcarriers in the cell (see figure.1).

Figure 1

Location of the users in the cell.

In our scheme, we propose an allocation of resources according to the position of the users.

Note that in this way users with high interference between sectors and at the ends of the cell will benefit from the same quality of service as users with high SINR. The signal to interference and noise ratio (SINR) of user k on subcarrier n at time t is given by: The overall channel gain is calculated as a sum of individuel gains :

  N P M m n m s G p s n m n k s G p s n k t s n k SINR           1 , , , , , (1)
S G t n k h P G A G t n k s G     2 ) ( , ) ( , (2)
The antenna gain of each BS sector is given by:

  G G G A G    max (3)
where dBi 15 max  G is the maximum antenna gain and we applying the two formulas below for horizontal and vertical radiation patterns respectively [START_REF][END_REF][START_REF] Yilmaz | System level analysis of vertical sectorization for 3GPP LTE[END_REF] :

                m A G , 2 12 min    (4) where      180 180     is the azimuth angle, ) 3sectors ( 65    is horizontal halfpower beam- width, and dB 30  m A is the front-back attenuation.                 v SLA G , 2 12 min    (5) where     0 15     
is the tilt angle, and The multipath fading channel ) ( , t n k h is modeled using Rayleigh fading, the channel is its time-varying, this time variation due to the movement of the mobile or objects within the channel [START_REF] Goldsmith | Wireless Communications[END_REF].

The propagation path loss

   s k d d P G 0  dependent on the Km d 1 0 
is the reference distance,  is the path loss exponent, for the location of the user k in the sector S , we calculate the distance s k d is given by:

    2 2 k y s y k x s x s k d     (6)
The shadow fading S G are generated with lognormal distribution and the random variations in signal amplitude follow a Gaussian distribution with mean of zero and standard deviation of σ [START_REF][END_REF]. Sectors from the same base station site use the same shadow fading values [START_REF] Ho | Multi-carrier Cell Structures with angular Offset[END_REF].

The transmission rate of each th k user terminal is calculated as from the SINR, is got by [START_REF] Goldsmith | Wireless Communications[END_REF]:

      t s n k SINR W t s n k r , 1 2 log ,   (7)
On the other hand the achievable rate of the cell can be given by:

  s n k r s N n s n k s n k SINR s n k R , 3 1 1 , , ,       (8)
where

s n k SINR ,
is the stat indication of users including the location of each user.

2.2.Problem Description

In this section, we present a mathematical model that is used in this article. Compared to other proposed models, the optimization approach proposed has the advantages of simplicity, flexibility and high accuracy that can be applied to other scenarios. The proposed resource allocation scheme is formulated as follows:

  N b b b C ,....., 2 , 1 
,where

  K n b , 1  (9)
C as the matrix of the resource assigned to the th n b mobile in th n subcarrier during a time interval according to PF Scheduling. In this scenario the optimization problems can be formulated as follows, our objective is to maximize the utility of all users, is defined as follow Problem:

(

C) u max δ t  ( 10
)
Obviously t is the index of time for different slot.

On the other hand, to achieve our goal, constraints are added to the optimization problem of proposed resource allocation schemes, two constraints, namely  The total transmit power assigned to users must be less than or equal to maximum transmitted power allowed max P [START_REF] Proakis | Digital communications[END_REF].

max 1 , P N n s n k p      K k , 1   (11)
 In our system, the number of active users can change position and also the channel state conditions of the users change, all these factors are contained in the SINR.

The System Throughput performance of all users is defined as follows

   T t gbest k T ST 1 ) , * ( 1 (12)
The System Fairness performance as a function of the number of users is defined as:

    K k K k C k C SF 1 log log ( 13
)
where k C is the resources allocated to user k and the K log term is a normalized factor.

Resource Allocation Algorithm

Our contribution relies on the use of Hybridation PSO-PFS algorithm. We will give a preview on the scheduler Proportional Fair in section 3.1. After, the overview of the PSO Algorithm in section 3.2. In section 3.3 we develop the Hybridation PSO-PFS Based Resource allocation algorithm in detail.

PFS Algorithm

The Scheduling is currently hosted in the MAC layer are based on opportunistic resource allocation. First appearance was proposed in [START_REF] Kelly | Rate control in communication networks: shadow prices, proportional fairness and stability[END_REF].

The scheduler must efficiently allocate available bandwidth resources provided by the physical layer to maximize system performance [START_REF]OFDMA System Analysis and Design[END_REF], in terms of throughput, fairness and delay. A mobile with a high SINR has a high priority, compared to users with a low SINR. Since PFS is based on variation in channel conditions mainly due to multipath fading, all mobiles get the same probability of access to resources across time [START_REF] Parruca | Throughput Analysis of Proportional Fair Scheduling for Sparse and Ultra-Dense Interference-Limited OFDMA/LTE Networks[END_REF]. As such, this algorithm offers a tradeoff between throughput and fairness [START_REF] Zeandji | Resource allocation in a multi-carrier cell using scheduler algorithms[END_REF]. However, its principle is based on a kind of feedback between the base station and the users to obtain an estimation of the channel state for each user and the instantaneous data rate in each subcarrier. The PF scheduler assigns each resource on the subcarrier n in   t slots, and then it monitors the average throughput in each subcarrier at each Transmit Time Interval (TTI) in a window of length tc [START_REF] Viswanath | Opportunistic beamforming using dumb antennas[END_REF][START_REF] Batista | What happens with a proportional fair cellular scheduling when D2D communications underlay a celluler network?[END_REF]. The objective function representing the PF Scheduling algorithm is

  K k t n k s Th t s n k R k ,...., 1 ; , ) ( , max arg *             (14)
where

) ( , t s n k R is the estimated instantaneous data rate   t n k s Th ,
the average throughput. The updated for scheduling as in [START_REF][END_REF],

                                        k k t n k s Th c t k k t s n k R c t t n k s Th c t t n k s Th ; , 1 1 ; , 1 , 1 1 1 , (15)

3.2.Overview of PSO Algorithm

A Particle Swarm Optimization algorithm is a stochastic optimization technique, based on the population, was proposed by Kennedy and Eberhart, inspired by behavior of bird flocking and fish schooling [START_REF] Kennedy | Particle swarm optimization[END_REF], looking for an optimal solution to the problem posed. Employing a whole of solutions potentials called Particles. Two factors characterize each particle its position and its velocity. Throughout successive iterations, each particle updates its position using its historical best position (pbest) in sight to reach the global best position (gbest) according to the following equations [START_REF] Brikh | Optimization of TSK Fuzzy Model Using New Improved PSO[END_REF]:

      ) 17 ( 1 1 (16) 2 2 1 1 1           iter j V iter j C iter j C (iter))) j C par (gbest r c (iter)) j C par (lpbest r c (iter) j Z(W*V ) (iter j V
where j is the number of particles.

iter is the iteration number. Ζ is construction factor; w is inertia weight; The updating process is essentially based on three components. The first term iter j V is the particle previous velocity; it serves as memory of the previous flight direction preventing particle from drastically changes of its direction. The second term

      iter j C j pbest 1 r 1 c   
is personal experience of the particle also called cognitive component. The effect of this term is that particle is drawn back to its own best position, modeling its tendency to return to places that were most satisfying on the past. The third term

    iter j C gbest 2 r 2 c   
represents the cooperation among particles, also named social component. The effect of this term is that each particle is also drawn towards the best position found by its neighbor [START_REF] Eslami | Asurvey of the state of the art in Particle Swarm Optimization[END_REF].

3.3.Hybridation PFS-PSO-Based Resource Allocation Algorithm

For the optimal allocation of resources, the base station collects mobile location information, if users in a cell sectoral are distributed in critiques locations with a low SINR cannot obtain a good quality of service. The idea in this paper, we propose a new resource allocation program in a trisectoral cell based on location of mobiles, channel conditions of users and their demands. This new program combines an evolutionary algorithm and the proportional fair scheduling. Hybridization between PSO and PFS provides a favorable sharing of resources for users in critical locations. However, the particle swarm optimization (PSO) policy is adapted to improve the performances of proportional fairness which is incorporated a set of constraints into the optimization problem.

The process of Resource Allocation scheme using Hybridation PSO and PFS algorithm operates as follows: First, we generate the resource allocation matrix by using Algorithm 1 which is defined as the vector of j-th particle.

  J j jN b j b j b j C ,..., 1 , ,....., 2 , 1   . ( 18
)
Second, the velocity of j-th particles j V is defined as the change of the particle positions.

Once the first population is generated, fitness evaluation is performed. The fitness function evaluation to be optimized used in the particle swarm optimization algorithm is the objective function given by Equation [START_REF] Sun | Device-to devise ressource allocation in LTE-advanced networks by hybrid particle swarm optimoization and genetic algorithm[END_REF] After updating the particles, the fitness function evaluate the new swarm is according as follows

  1 1    iter j iter j C f  (19)
Update the pbest for each particle is calculated:

) ( , 1 iter j C f iter j lpbest f iter j lpbest ietr j lpbest     (20)
Update de gbest represent the maximal fitness: [START_REF]OFDMA System Analysis and Design[END_REF] 1: for user k=1 to K do 2: Locating the position of the mobiles in the cell 3: Generate different channel responses for each users, sub-carrier and time slot using (1) 4: for slot t=1 to T do 5: for carrier n=1 to N do 6:

    1 max 1    iter j lpbest f iter gbest
Storing in a matrix, different values of rate, for each user, sub-carrier and time slot using (7) 7:

end for 8: end for 9: end for 10: Initialize average throughput for all users 11: k=1: users 12: for slot t=1 to T do 13: for carrier n=1 to N do 14: Generate matrix PFS using [START_REF] Pirinen | A brief overview of 5G Research Activities[END_REF] 15: Updated for scheduling using (15) 16: end for 17: end for

Algorithm 1 PF Scheduling

The proposed solution of the resource allocation using the Hybridation PSO-PFS is described in Algorithm 2. The swarm size is a dependent problem and generally kept in between 20 and 50 [START_REF] Eberhart | A new optimizer using particle swarm theory[END_REF]. The positions and velocities of particles are updated until the number of iteration is achieved; the maximum number of iteration is set to 100 according to the constraints posed. In this problem, the acceleration coefficients and construction factor are set to 1 and 0.7 respectively, at each iteration the inertia weight is calculated as follows Calculate the fitness value according to (10) 10: end for 11: Update the velocity iter j V using (16) 12: Update particle position using [START_REF] Goldsmith | Wireless Communications[END_REF] 13: Update the best local position and global best for each particle according to the fitness value 14: end while 15: Output gbest 16: Compute the system performances for each users using [START_REF] Alitaleshi | Ameliorated Ressource Allocation in Two-tier Femtocell-Macrocell Networks with Six Directional Antennas for Macrocells[END_REF][START_REF] Ho | Multi-carrier Cell Structures with angular Offset[END_REF]

Simulation and Results

In this section, we present the evaluation of the proposed algorithms. The system-level parameters are summarized in table 1; we have designed a simulation area of 1km×1km. We assume three types of services, video, voice and transmit data. Furthermore, the approach studied must satisfy a high quality of service, namely a very high throughput, fairness between users and delay constraint. However, a comparison between the proposed schemes is analyzed. In a tri-sectoral 5G cell, for each sector the users can have different throughput. In this scenario, at the cell level the reuse of frequency 1 is applied, the users are uniformly distributed as well as the service type; Figure 2 shows the position of each user in the cell. In addition, users with critical positions suffer interference and cause high delays and user's dissatisfaction. In this context, the PFS algorithm takes into consideration the users channel conditions and the PSO is a tool to solve the allocation problem. Figure 3 illustrates the utility of all users and the convergence of the PSO for a number of iterations is 100, this confirms that the PSO is an algorithm capable of solving the We had a look at the resource allocation for each user taking into account their channel conditions using the PFS algorithm and the resource allocation with PSO-PFS hybridization, as we can see in Figure 4, a random flow distribution is made taking into consideration the user's position and channel status of each user, the throughput performance of the RA hybrid PSO-PFS is higher than that of the PFS, due to the particularity of the PSO algorithm, which makes maximum use of the research space, which allows convergence and achieves higher system throughput.

Figure 5 shows the Fairness performance as a function of the number of users. As it can be seen that the equity index is between 0.9 and 1, it is shown that the allocation by hybrid PSO-PFS ensures fairness between the users.

Figure 5: Fairness performance

Concerning the delay constraint, if we compare the two proposed schemes, the simulation results give us an approximation of the number of users that can be served; namely, the larger the number of users in the cell, the delay constraint is important, in that case, with zero delay probability the hybrid PSO-PFS algorithm can serve 60% compared with the PFS which is 40% (see figure 6 (a)), as we can also see in the figure 6 (b) the PSO-PFS hybrid algorithm reaches zero probability faster thanks to its convergence towards the optimal solution, which allows it to transmit more resources in each timeslot, and they are sufficient to satisfy the needs of all users with different types of service and according to their position.

Conclusion References

In this work, we proposed an optimization approach to solve the resource allocation problem in sectoral cellular networks (4G and 5G system) whose objective is to maximize throughput and ensure users satisfaction. First, we introduced a mathematical model studying the state of channel conditions of each user position. Then, the proposed approach was optimized using the PSO-PFS hybrid algorithm, the evolutionary particlebased PSO is adapted to make maximum use of the research space. In addition, our proposed scheme revealed an improvement in the quality of service. Finally, the performance evaluation of the studied system confirms that the PSO-PFS hybridization approach allows a high throughput for all users by ensuring fairness while respecting constraints. However, resource allocation through hybridization could be extended to other approaches such as ensuring a high quality of service for loaded sectors.

  the transmit power on the th n subcarrier to th k mobile in S sector, N P is the noise power spectrum density Gaussian at each time slot, n m s p , is the power for user th k on the same subcarrier th m , and n k s G , is the channel gain, the users suffers from the Path loss, multipath fading and Shadow fading.



  is vertical halfpower beam-width and 10  v SLAis side lobe attenuation.

Figure 2 :

 2 Figure 2: Positions of all users in the cell

Algorithm 2

 2 RA-Hybrid PSO-PFS allocation problem and improving the scheduler performance.

Figure 3 :

 3 Figure 3: Convergence of PSO iterative algorithm

Figure 4 :

 4 Figure 4: Throughput performance

  Probability delay as a function of the (b) Probability delay as a function of the time numbers of users

Figure 6 :

 6 Figure 6: Delay constraint

Table 1 :

 1 Simulation parameters

	Parameters	Values
	Channel Bandwidth	20MHz
	Carrier Frequency	2.4Ghz
	Number of subcarrier 1200
	Grid layout	1 cell hexagonal
	Cell radius	1 km
	BS Transmitter Power 43 dBm
	Slot duration	0.5ms
	Subcarrier Modulation 16QAM
	Number of users	30
	Swarm size of PSO	50


Jérôme Ros

Carole Puig

Olivier Passarrius

Julien Mantenant

Jérôme Kotarba

Nicolas Guinaudeau

ARCHAEOBOTANICAL CONTRIBUTION TO THE HISTORY OF FARMING PRACTICES IN MEDIEVAL NORTHERN CATALONIA (8 TH -14 TH C.)

Keywords:

The High Middle Ages is considered as a period of major changes for the agricultural world. These changes, which intervene as soon as the 9 th c. in Catalonia and reached their full potential between the 12 th and the 13 th c., had an impact on farming practices and on the exploited landscapes. Although well known through the study of textual sources, agrarian productions and practices were, so far, poorly documented by archaeology in northern Catalonia (Pyrénées-Orientales, France). The increase of archaeobotanical investigations in this region allow us to present a first review of medieval farming practices. Based on the study of fifteen rural sites, this paper aims to document, through archaeobotanical data, the characteristics of northern Catalan agriculture between the 8 th and the 14 th c. (cultivated crops, prevalence of certain species, farming practices associated, types of exploited landscapes), while detecting some evolutions over the long term.

INTRODUCTION

During the High Middle Ages, the Catalan rural world underwent decisive changes. The strong economic and demographic growth that affected the whole of the western Mediterranean, which began in Catalonia in the 9 th century, reached its full potential in the 12 th and 13 th centuries (BONNASSIE 1975(BONNASSIE -1976)). During this period, some urban centres experienced such a rapid expansion that production in the surrounding countryside was no longer sufficient to supply them, forcing them to import food products from other parts of the Mediterranean (for ex. [START_REF] Reyerson | Urban/Rural exchange: reflections on the economic relations of town and country in the region of Montpellier before 1350[END_REF][START_REF] Puig | Les campagnes roussillonnaises au Moyen Age : dynamiques agricoles et paysagères entre le XII ème et la première moitié du XIV ème siècle[END_REF]. In the northern part of medieval Catalonia, corresponding to the current French department of the Pyrénées-Orientales, the extremely rapid growth of the city of Perpignan contributed to the demographic and economic development of the region, the city developing markets through which many common or exotic plant products, sometimes imported [START_REF] Puig | La place des fruits en Méditerranée nord-occidentale à partir des actes de la pratique et des tarifs marchands (XII ème -Première moitié XIV ème siècles)[END_REF], circulated, opening the way for the introduction of new plants and foodstuffs into the agricultural and food heritage of this region.

During this period, the Roussillon countryside was reorganized. Thus, from the 9 th -10 th centuries, a new network of rural farms, isolated or grouped into hamlets, both on the plain and in the foothills, began to emerge (PASSARRIUS et alii 2008). Some new occupations last only a few centuries (PASSARRIUS et alii 2008), while others, the majority, have survived to the present day, forming the ancient cores of the urbanized areas of the present plain (PASSARRIUS et alii 2008: 46). The absence of excavations in these ancient nuclei has long prevented an optimal reading of land-use during the High Middle Ages. The realization of a Collective Research Project1 and the multiplication of preventive archaeology and pedestrian prospecting operations made it possible to make up for this lack, renewing our knowledge of the occupation of the countryside during this period (for ex. [START_REF] Passarrius | Projet Collectif de Recherches, Villages d'hier, villages d'aujourd'hui, Plaine du Roussillon, Rapport annuel[END_REF].

In parallel with these changes in the rural tenure framework, farming practices underwent major technical changes, leading to the development of new agrarian dynamics. These, essentially documented by textual sources of the end of the period (12 th -14 th centuries), are manifested by the creation of new terroirs, an increase in drainage movements, the improvement of water control (irrigation techniques, mills), a significant exploitation of wetlands (marshes) for the creation of grasslands and cereal growing, as well as an increase of specialized or even speculative crops (for ex. PUIG 2003).

While research on the evolution of land use and agrarian techniques during this period has been particularly dynamic in recent decades, the question of crop production and medieval food heritage exploited in northern Catalonia has long remained poorly documented. Several pioneering works on written sources have begun to address this theme, highlighting and commenting on crop production and foodstuffs, some throughout Catalonia (BONNASSIE 1975(BONNASSIE -1976[START_REF] Bonnassie | La Catalogne au tournant de l'an mil[END_REF], others in Cerdanya [START_REF] Rendu | Un aperçu de l'économie cerdane à la fin du XIII ème siècle : draps, bétail et céréales sur le marché de Puigcerdà en 1280-1281[END_REF]. Later, the study of other types of texts made it possible to detail the medieval agricultural productions of the Roussillon plain and Cerdanya [START_REF] Puig | Les campagnes roussillonnaises au Moyen Age : dynamiques agricoles et paysagères entre le XII ème et la première moitié du XIV ème siècle[END_REF](PUIG , 2005a(PUIG , 2005b[START_REF] Puig | La place des fruits en Méditerranée nord-occidentale à partir des actes de la pratique et des tarifs marchands (XII ème -Première moitié XIV ème siècles)[END_REF][START_REF] Puig | L'apport de l'étude du stockage à notre connaissance de la conjoncture alimentaire autour de 1300 (Catalogne, Roussillon, Languedoc), Les disettes dans la conjoncture de 1300 en Méditerranée occidentale[END_REF]. More recently still, the rise of carpology has made it possible to take a new look at medieval agriculture in Roussillon (ROS 2020), and the obtained data, compared with those from textual sources, made it possible to draw up a first image of the range of produced, marketed and consumed plants in the northern part of Catalonia between the 10 th and the 15 th centuries (fig. 1) (ROS et alii 2016). These various works, of great diversity, pointed out certain shortcomings. There was a lack of data for the 9 th -11 th centuries, due both to the scarcity of available textual sources and to the lack of studied carpological series for this period. Moreover, if the first interdisciplinary synthesis carried out in northern Catalonia made it possible to draw up a first critical assessment of the available sources and to draw up a list of the region's agricultural productions, it was based only on unquantified carpological data, which did not allow a precise restitution of the agro-horticultural spectrum exploited, of its components, nor the importance of each plant species within medieval agricultural productions.

The increase in the number of excavations in medieval rural contexts in recent years, coupled with the implementation of an appropriate sampling strategy, makes it possible to propose a new synthesis, based on a substantial corpus of sites and quantified carpological data. The approach, covering a coherent geographical area (Roussillon plain) over a long chronology (8 th -14 th centuries), aims to capture the agro-horticultural characteristics of the local agrarian system, namely the main species exploited throughout the period under consideration, and new species, whose rythms and pathways of introduction can be discussed in the light of carpological and textual sources.

MATERIAL AND METHODS

The corpus includes fifteen archaeological sites, covering a chronology from the 8 th to the 14 th century AD, the 10 th -11 th centuries being those documented by the largest number of sites (fig.

2, 3). They are spread out from the coast of Roussillon to the first heights of the Vallespir, with a maximum of sites located on the plain between the Têt and Tech rivers. The sites were not investigated in a homogeneous manner, some of them having benefited from long planned operations and others having only been approached by means of surveys as part of preventive operations. Also, the areas excavated vary, ranging from less than 10m 2 for Place de la Cathédrale (Elne) to more than one hectare for Les Gavarettes (Argelès-sur-Mer).

A total of 64 archaeological contexts were sampled. The 98 samples issued from the 64 contexts were collected by the excavation teams between 1980 and 2016, in contexts of different natures but in relation with habitat or agricultural activities: silos, pits, fireplaces, ovens, planting pits and detritus levels. Often, due to time constraints, the preventive nature, since the aerobic conditions of these sites only maintain carbonized or mineralized seeds. The presence of charcoal or charred seeds visible during the excavation of the structures was therefore the main criterion for sampling. The average volume is of 10 litres of raw sediment per sample, but varies according to the site, structure and analyses carried out (minimum volume encountered in the corpus: 200 millilitres, maximum volume: 140 litres).

The extraction of archaeobotanical remains was not always adapted to the sought material: in the absence of a specific protocol for the study of carporests, the screening of four of the sites was carried out under water, only through meshes between 2 and 6 mm in diameter. The seeds were then hand-sorted directly from the screening refusals by the excavation teams. This method, which is inefficient in identifying seeds of very different sizes and shapes, has led to several biases in the representativeness of the carpological assemblages that can be preserved [START_REF] Marinval | Les graines et les fruits : la carpologie[END_REF]. These sites, which are fortunately in the minority, correspond only to ancient excavations; most of the samples were screened by flotation on fine meshes (0.5 and 2mm) by the excavation teams or by the author. Once the samples were collected, screened, and stored, the carpological material was extracted and analyzed in the laboratory2 (sorting and extraction of carporests from the screened sediment, identification, quantification, interpretation). Only samples from the Camp del Rey (Baixas) site have not been the subject of a complete quantified study; the carporests collected and identified, even if they are not counted, however, make it possible to assess the frequency of the cultivated/exploited taxa per context.

RESULTS

The 98 samples yielded a total of 111,401 carpological remains, of which 21 taxa considered as cultivated or harvested were identified: 6 cereals, 4 legumes, 2 vegetables, 9 fruit trees and 2 technical/oilseed plants (fig. 4, 5 ,6).

We have decided, for the whole considered period, to evaluate the frequencies of appearance of cultivated species, by counting the occupations and contexts in which the different taxa are present (fig. 7). The use of this method makes it possible to highlight the main exploited plants by smoothing out the obtained information [START_REF] Popper | Selecting Quantitative Measurements in Palaeoethnobotany[END_REF][START_REF] Pearsall | Palaeoethnobotany: A Handbook of Procedures[END_REF]. Indeed, working from the number of raw remains for each of these taxa, or their percentage and contribution within each assemblage, would have led to an over-representation of certain taxa, favoured by their economic status or by their ability to be preserved during carbonization (e.g. cereals). Working from the presence/absence of taxa helps to mitigate this over-representation effect.

CEREALS

Hulled barley (Hordeum vulgare) and naked wheat (Triticum aestivum/durum) are the two cereals most frequently attested in the samples (13 and 12 occurrences on 15 sites), by their grains and, more rarely, by chaff elements (lemmas, rachis) (fig. 4,7). Barley exceeds naked wheat by its frequency per site but also per context, appearing in 52 of the studied contexts compared to 43 for naked wheat. Despite the presence of naked wheat rachis, it was rarely possible for us, due to their state of conservation, to determine whether the wheat used was a hexaploid (T. aestivum l. s., wheat in the broad sense) or tetraploid (T. durum, durum wheat, T. turgidum poulard wheat) one; only the Vilarnau site delivered a rachis article identified as the hexaploid type. The third cereal is the common millet (Panicum miliaceum), present in 7 sites (17 contexts), followed by the foxtail millet (Setaria italica), present in 4 sites (5 contexts). The importance of these two cereals is certainly underestimated, as their grains can only be recovered by fine sieving of samples, from which some sites have not benefited.

Indications of rye exploitation remain weak, being identified in only 3 of the sites (5 contexts), by small quantities of grains and rachis articles. Oats (Avena sp.) are recorded as grains in 2 sites and 5 contexts. The presence of lemmas at the Royal Castle of Collioure makes it possible to formally identify the presence of the cultivated species (A. sativa). However, the low overall grain quantity does not confirm its crop status, as oats can also behave as a weed in other cereal crops. The absence in Roussillon of other hulled cereals, such as emmer (Triticum dicoccum), spelt (T. spelta) and einkorn (T. monococcum), is to be highlighted for the period under consideration.

LEGUMES

In the corpus, 4 legumes are recorded: faba bean (Vicia faba var. minor), sweet pea (Pisum sativum), lentil (Lens culinaris), and common vetch (Vicia sativa) (fig. 5,7). With the exception of faba beans, which occur in 6 sites (7 contexts), other legumes appear very anecdotally, in 1 (lentil, vetch) to 2 sites (sweet pea), and never by a significant amount of remains. This rarity is not related to the preservation of the material, as legumes seeds are as resistant to carbonization as cereals, nor to the extraction methods applied, their seeds being generally larger than or at least equal in size to that of cereals.

VEGETABLES

The corpus delivered 2 taxa in the vegetable category (fig. 5). A charred bulblet, recorded in one of the samples from the site of the Royal Castle in Collioure dating from the 14 th century, has been identified as belonging to the genus Allium; however, it was impossible for us to specify whether it was a bulblet of garlic (Allium sativum) or onion (Allium cepa) due to its state of conservation. The site of Place du Général Foixet in Pézilla-la-Rivière has delivered several seeds attributed to a taxon recognized for the first time in Roussillon: spinach (Spinacia oleracea). The seeds come from 2 contexts dated between the 11 th and the middle of the 13 th century: a household level characterized by the numerical richness and diversity of the encountered plants, and a soil level, probably linked to a rubéfied area interpreted as a possible second household.

FRUIT PLANTS

Within the corpus, grapevine (Vitis vinifera) is the most frequent fruit plant; it is identified in 12 sites (38 contexts), but its remains are really abundant only in Gavarettes, Argelès-sur-Mer, and Ruscino, Perpignan (fig. 6,7). The second fruit plant in the corpus is the olive tree (Olea europaea), present in 7 sites (13 contexts), only in the form of stones or stone fragments.

TECHNICAL/OILSEED PLANTS

The studied corpus identified 2 technical/oilseed plants: cultivated flax (Linum usitatissimum) and hemp (Cannabis sativa) (fig. 6). The first is documented in 5 of the sites (9 contexts) and the second in a single site (1 context) (fig. 7). Their rarity is probably due to the disappearance of these seeds, which are subject to bursting during carbonization.

GENERAL DISCUSSION

WHAT AGRICULTURAL HERITAGE WAS BEING EXPLOITED IN MEDIEVAL NORTHERN CATALONIA?

The convened corpus makes it possible to recognize the existence of an agrarian system based on the exploitation of a wide diversity of annual and perennial species. The carpological data compared to textual sources make it possible to propose a discussion on the exploited plants and the cultural practices associated with them during the High Middle Ages.

An omnipresent cereal production

Cereals, particularly hulled barley and naked wheat, form the basis of the Roussillon agrarian system throughout the period under consideration. Within this cereal pair, classic for the medieval western Mediterranean (for ex. RUAS 2005, 2010; PEÑA-CHOCARRO et alii 2018), barley occupies a first-rate position, dominating naked wheat both by its frequency per site and per context. This high frequency had already been highlighted by the carpology in Roussillon for Antiquity and the first centuries of the Middle Ages (ROS and RUAS 2017;ROS et alii 2019ROS et alii , 2020)), confirming the important role of the species in local agriculture during historical periods. The exact role of the species is difficult to clarify from carpological assemblages; while being the most referenced cereal in textual documentation from the 12 th century onwards, it then seems to be used both for human and animal consumption [START_REF] Puig | Les campagnes roussillonnaises au Moyen Age : dynamiques agricoles et paysagères entre le XII ème et la première moitié du XIV ème siècle[END_REF]. Naked wheat, the second main cereal crop on the plain, played as versatile a role as hulled barley (human food, fodder) during the first centuries of the Middle Ages (ROS et alii 2019(ROS et alii , 2020)). In the High Middle Ages, there was a duality between textual and carpological sources. According to the written documentation from Roussillon, wheat seemed to be reserved, until the 13 th century, to a privileged population, unlike barley, which would constitute the basic food of the people of Roussillon [START_REF] Puig | Les campagnes roussillonnaises au Moyen Age : dynamiques agricoles et paysagères entre le XII ème et la première moitié du XIV ème siècle[END_REF]. However, the carpological corpus suggests that naked wheat has also played an essential role in the region's peasant diet, with many of the sites delivering grains of this cereal in samples interpreted as domestic consumption rejects. For both barley and naked wheat, the mixed nature of the carpological samples makes it difficult to accurately identify the farming practices associated with them (soils of origin, sowing season, cutting height). If the medieval texts of Roussillon tend to consider wheat as a winter crop (PUIG 2003: 160) It is equally difficult to identify the role of millets in the existing agro-horticultural system, although they seem to be spring crops linked to wet, irrigated or marshy soils (ROS et alii 2016: 128). According to Roussillon text sources, plots taxed in millet differ from those taxed in barley and wheat in their location (PUIG 2003: 331), suggesting that millet did not necessarily participate in a crop cycle alternating with winter cereals.

For both rye and oats, their cultivation in the plain is difficult to demonstrate on the basis of carpological data alone. Rye has been identified in the Roussillon plain since the first centuries of the Middle Ages, although it is not possible to determine whether it was cultivated locally or imported from the foothills [START_REF] Puig | Les campagnes roussillonnaises au Moyen Age : dynamiques agricoles et paysagères entre le XII ème et la première moitié du XIV ème siècle[END_REF]. In the High Middle Ages, its culture was identified by

Annual secondary crops: first carpological indicators of the existence of garden crops in Roussillon?

The corpus of studied sites makes it possible to identify, in addition to cereals, other categories of plants from annual crops, such as legumes (faba beans, peas, lentils, vetches), technical/oilseed plants (flax, hemp) and some vegetables (spinach, garlic/onion). With the exception of spinach, all these taxa are known and exploited in medieval or even ancient Roussillon (ROS and RUAS 2017), some of them flourishing from the 6 th century onwards, such as flax for example (ROS 2020; ROS et alii 2020). The quantities and registered frequencies of these taxa in carpological samples place them in a secondary position among annual crops. The reasons for the low number of mentions of these different taxa can be varied; if it is not caused by the punctual or secondary nature of their cultivation, it can be related to the consumed part of the plant3 that does not favour its presence in carpological samples (in the case of vegetables), to the way in which the remains are preserved (carbonisation), which disadvantages taxa with fragile seeds (in the case of oilseeds), to the type of contexts sampled, which are too restricted, or to the very status of the sampled sites.

Despite the fact that their presence in the samples is, on the whole, punctual, it seems that some categories, such as legumes and vegetables, are more varied and deliver more remains in the later contexts of the corpus. The case of the site of the Place du Général Foixet in Pézilla-la-Rivière is particularly interesting: the samples dated between the 11 th and the middle of the 13 th century deliver not only spinach seeds but also cereal grains, mainly foxtail and common millets, as well as hulled barley, faba beans and wild plant seeds considered as classic spring growing weeds (goosefoot, knotweed, wild millets). The joint presence of these different plant categories in the same samples was discussed, and the hypothesis of foxtail millet harvests on a garden plot with several types of crops (legumes, vegetables, spring cereals) was put forward, although the isolated nature of the discovery does not formally confirm the existence or frequency of such a practice.

While the material evidence of the existence of garden crops remains tenuous, the texts provide a more precise account of this. Species cultivated on a plot-by-plot basis do not appear to be fixed and depend on both their location and time of year. The medieval Catalan garden (hort) is a small plot of land with a variety of crops: cereals, vegetables (leeks, carrots, onions, turnips, eggplants, cucumbers, gourds, etc.), legumes, herbs, fruit trees, and textile plants such as hemp and flax [START_REF] Puig | Les campagnes roussillonnaises au Moyen Age : dynamiques agricoles et paysagères entre le XII ème et la première moitié du XIV ème siècle[END_REF]. These are areas close to the habitat, which would have benefited from the proximity of wetlands or irrigation. The presence of the different plant categories registered at Place du Général Foixet does not therefore contradict the image we can have of the medieval Roussillon garden as it appears through the textual documentation. The data from the carpological corpus, although still fragile concerning this type of crop, seem promising and need to be verified in future studies.

Fruit production difficult to identify

The spectrum of consumed/exploited fruit plants in medieval Roussillon is part of the typical western Mediterranean agri-food heritage known for historical periods. Viticulture, developed during the Antiquity as the main fruit production associated with olive growing (ROS and RUAS 2017; ROS 2020; Ros et alii 2020), remains the main crop in the region. In the Gavarettes site in Argelès-sur-Mer, grapevine is present in the form of seeds, berries and pedicels; the composition of the samples suggests that some correspond to wine by-product (crushing or pressing residues) (ROS 2020). Elsewhere, it is mainly identified by small quantities of seeds, which do not allow the identification of their origin (residues from the consumption of fresh or dried fruits, wine by-product). The olive tree, second fruit species of the corpus, is only documented by whole or broken stones, indicating the rejection of fruit consumed for their flesh rather than waste linked to oil production. The other fruit plants, hazelnut, umbrella pine, plum, hawthorn and oak, appear only occasionally in the samples of this period, the remains recorded testifying to the occasional consumption of these fruits.

The Roussillon rural spectrum does not currently display any of the non-native fruits introduced by trade or cultivated in the northwestern Mediterranean area between Antiquity and the Middle Ages, for example blackberries (Morus nigra) or cucurbits (Cucumis melo, Cucumis sativus, Lagenaria siceraria). We also note the absence of certain fruits attested at the very beginning of the medieval period in Roussillon: cherries (Prunus avium and P. cerasus), nuts (Juglans regia), lentiscus pistachio nuts (Pistacia lentiscus) (ROS et alii 2019, 2020; ROS 2020). The absence of mentions of these fruits can be explained by the lack of carpological assemblages from wet (wells) and/or mineralized (latrines) contexts that favour the recording of a greater diversity of fruit trees.

As the data currently stand, it is difficult to provide a satisfactory picture of fruit production in medieval Roussillon. Indeed, although the carpological data show a certain diversity, they do not allow us to understand the places where these different fruit trees are grown 4 , and the 4 Only the comparison of carpological data with those from anthracological analyses would make it possible to establish the local origin of fruit trees registered in the corpus sites; this type of analysis is however less developed in Roussillon and a first synthesis remains to be carried out.

punctual nature of the discoveries prevents us from fully grasping the importance of each taxon within the food and peasant cultures at that period. The comparison with data from textual sources is hardly more informative. Indeed, the acts of the practice hardly evoke fruit trees, almost never fruit, outside the main productions of grapes and olives; wild fruit trees, harvested in the context of domestic activities, are thus ignored. While the toponyms indicated in the medieval records suggest the presence of other species (e. g. chestnut, pear) in the local landscape, the main information available is issued from the study of market tariffs (leudes), which only mention fruits that are traded or subject to taxes. In addition, the fruits indicated in these sources may have various origins, sometimes distant, which do not allow local productions to be better documented.

RHYTHMS AND WAYS OF INTEGRATING "NOVELTIES": CROSSING

SOURCES

Various studies have shown that to shed light on the history of a plant, it is necessary to study it over a long period of time, by critically convening and crossing different documentary sources (HAUDRICOURT and HÉDIN 1943;[START_REF]Les plantes exploitées en France au Moyen Age d'après les semences archéologiques, Flaran 12, Plantes et cultures nouvelles en Europe occidentale au Moyen Age et à l'époque moderne[END_REF][START_REF] Comet | L'iconographie des plantes nouvelles ou une approche des débuts de la botanique moderne[END_REF][START_REF] Bakels | Access to luxury foods in Central Europe during the Roman period: the archaeobotanical evidence[END_REF]RUAS et alii 2015). The "longue durée" and diversity of sources would indeed make it possible to understand the ways and stages of integration of each plant: appearance on urban markets as exotic commodities, integration into food and/or into the "landscape" of the elites (e. g. royal, ecclesial, urban gardens), appropriation by other population strata before integration into the food and agricultural heritage of peasant populations. Within this evolutionary, purely theoretical scheme, some stages may not be followed; some plants, without particular social, symbolic or market values, could thus have entered the peasant agri-food heritage without going through the previous stages, and conversely, others could have been present on the markets without ever reaching the peasant culture stage.

In the context of this work, it seemed interesting to us to return to the introduction of three plants in medieval northern Catalonia: apricot, orange and spinach (fig. 8). Through these three plants, it is possible, in the light of archaeobotanical and textual sources, to question the rhythms and ways of integrating novelty into the agro-horticultural heritage of this region.

The apricot tree: a very late arrival

The history of the apricot tree in Roussillon has so far been little discussed, and despite its role in current agricultural production, the origin of its introduction and cultivation remains unknown. Its culture is documented by textual sources in Spain and Sicily in the 9 th -10 th centuries, and it was also reportedly introduced "without delay" into Roussillon by the Arabs (ALBERTINI 2013: 243). However, the fruit is not mentioned either in the leudes (trade and customs tariffs) or in the region's capbreus [START_REF] Puig | Les campagnes roussillonnaises au Moyen Age : dynamiques agricoles et paysagères entre le XII ème et la première moitié du XIV ème siècle[END_REF][START_REF] Puig | La place des fruits en Méditerranée nord-occidentale à partir des actes de la pratique et des tarifs marchands (XII ème -Première moitié XIV ème siècles)[END_REF]ROS et alii 2016), and has not yet been the subject of any archaeobotanical discovery in the area (ROS et alii 2018;[START_REF] Drendel | ans d'agriculture en Roussillon, Productions végétales et terroirs protohistoriques, antiques et médiévaux, Éditions Mergoil[END_REF].

The very first mention of apricot trees is issued from a text dating from March 1347, apricot trees being taken from a royal fig grove to create a new pleasure orchard at the south of the royal castle of Perpignan (CATAFAU 2018: 18). A. Catafau notes in this regard that the spelling of the term, also used in 1418, "aribrecotorum", indicates a lack of knowledge of the word by the royal notary, probably because of its rarity and the recent introduction of the species. It was mentioned later, at the beginning of the 17 th century, by M. Agusti, a Catalan agronomist, who mentioned it among the fruit trees to be planted in the "huertos" (AGUSTI 1617).

If apricot cultivation was practised relatively early in al-Andalus, it would not have spread rapidly to Christian northwestern Mediterranean, as the tree only entered the royal gardens of northern Catalonia between the 14 th and early 15 th centuries. Its integration into the Catalan peasant sphere remains unknown but would occur much later than what the scientific literature proposed until then, possibly during the modern era. In medieval Mediterranean France (Languedoc, Provence), the tree seems to be absent from gardens and cultivation areas (for ex. [START_REF] Coulet | Aix-en Provence : espace et relations d'une capitale : milieu XIV e s.milieu XV e s[END_REF]STOUFF 1997: 75); only one archaeological stone from a well filling dated from the 14 th -15 th centuries in Montpellier (FIGUEIRAL 2017) attests to the consumption of the fruit, who was certainly not widespread at the time (RUAS et alii 2015: 359).

The slow integration of the orange tree

The first mentions of citrus fruits in Roussillon date back to the 13 th century. The second leudaire of Collioure 5 thus evokes the sale of limons e pomers e terongers. If the terms limons and terongers make it possible to recognize lemon and orange, the term pomers is more enigmatic; if the attribution of this term to pomegranate has been considered, it seems to appear more generally in the form of granarios. This term would therefore also refer to a citrus fruit, a group with which it is associated in the lists, without it being possible to attribute it precisely to one of the fruits circulating in the Mediterranean Basin at the time (e. g. grapefruit, citron, mandarin, bergamot). Spain, for example, has been cultivating cedar since the 7 th century, lemon and bitter orange since the 10 th and 11 th centuries. Lemons and oranges seem to be fairly recent products on the Collioure market: the leude tariff for them is followed by the sentence that all products that "are neither named nor known to the leuders [responsible for taking the leude] are worth according to the previous products"6 . At that time, these would therefore be new products, but that we know enough to be able to name them7 .

Although citrus fruits appeared on the urban markets of Collioure and Perpignan between the end of the 13 th and the beginning of the 14 th century, the first mention of cultivation in Roussillon dates back to March 1347: near the royal apartments of the Royal Castle of Perpignan and the garden that borders them, in the queen's small meadow (pradet), orange trees (torongers) adorn a flower bed (CATAFAU 2018: 18). In 1419, it is also mentioned the purchase of 37 orange trees and 30 peach trees (presseguers) for the king's fig grove (CATAFAU 2018: 17). Later, Jérôme Münzer, a German doctor and geographer going to Spain, mentioned during a stopover in Perpignan between the 17 th and 19 th of September 1494, the presence of orange trees in the irrigated gardens of the knight Sigebert, located outside the city of Perpignan, near the ramparts (TARAYRE 2006: 42). While in Barcelona on the 21 th of September 1494, he also observed orange trees in the cathedral gardens, in several urban gardens and in those of the city's merchant's house (La Loya) (TARAYRE 2006: 44-46). The cultivation of the orange tree seems to have developed in the gardens of the wealthy populations during the 15 th century, the tree also being mentioned in the garden of the Aix merchant Guillaume Aymeric in 1427, and in Ollioules in the 15 th century (STOUFF 1997: 76). At the beginning of the 17 th century, citrus fruits were mentioned by the Catalan agronomist M. Agusti, who stressed out that a "garden" (huerto) where no "naranjos, cidros, limas, limones" are present could not be called perfect (AGUSTI 1617).

The rapid spread of spinach

Spinach is considered a novelty of the medieval period, with the first mentions of the species in the western Mediterranean appearing between the 10 th and the 11 th century in the textual sources in al-Andalus. The plant then spreads relatively quickly. Between the end of the 12 th and 13 th centuries, its carpological mentions multiplied. The oldest in Europe comes from the Pyrenean site of Montaillou (Ariège, France), located at an altitude of 1,354 m, where spinach seeds appeared in a fireplace and a pit of one of the village houses (HALLAVANT and RUAS 2014).

It has since been discovered in two medieval sites in southern France: a context dating from mid-12 th / mid-13 th centuries in the Tarn (HALLAVANT unpublished) and an urban context from the 14 th century in Languedoc (FIGUEIRAL unpublished).

In Roussillon, the leudes of the 14 th century indicate its sale on the markets, subject to urban regulations, and its production taxed on the same basis as that of other common vegetables (leek, cabbage, carrot, etc.) [START_REF] Puig | Les campagnes roussillonnaises au Moyen Age : dynamiques agricoles et paysagères entre le XII ème et la première moitié du XIV ème siècle[END_REF]. Following the discovery of spinach carporests in levels dated between the 11 th and the middle of the 13 th century at Place du Général Foixet (Pézilla-la-Rivière), the question of the date of its introduction and cultivation in the region is raised. Indeed, if the spinach carporestes of Montaillou constitute for the moment the oldest mention of this plant in the western Mediterranean, the carporestes of the Roussillon site could constitute an even older mention, contemporary with the first mentions of the plant in al-Andalus and several centuries earlier than the first textual mentions in Roussillon.

Unfortunately, the contexts from which these carporests are issued, dated by the associated ceramic material, cover a chronology too wide to allow us to reveal precisely the age of the remains8 . However, it is now certain that new type species of vegetables are present in Roussillon at least from the 13 th century and that they are quickly integrated into the local agro-horticultural sphere. It is difficult at this point in time to identify the pathways by which spinach appears in the region. In Montaillou, the hypothesis is that during the 12 th -13 th centuries, the Pyrenean shepherds favoured the entry into France of the plant already cultivated in al-Andalus, following regular contacts with the South Pyrenean populations during transhumance in Muslim lands [START_REF] Hallavant | The first archaeobotanical evidence of spinacia oleracea L. (spinach) in late 12 th mid 13 th century A.D. France[END_REF].

A COMMON AGRICULTURAL HERITAGE IN MEDIEVAL CATALONIA? FIRST TRANSPYRENEAN COMPARISON

Beyond documenting the share of stability and innovation at the heart of the northern Catalan agri-horticultural system, we wanted to address the issue of space. Due to the strong documentary disparities between the north and south of medieval Catalonia, it was difficult, until very recently, to propose a transpyrenean carpological synthesis; indeed, if the rural sites studied became numerous in northern Catalonia (ROS et alii 2018), they remained little addressed in southern Catalonia, with research focusing on urban sites, particularly on Islamic contexts [START_REF] Alonso | Agriculture and food from the Roman to the Islamic Period in the North-East of the Iberian Peninsula: archaeobotanical studies in the city of Lleida (Catalonia, Spain)[END_REF]ALONSO et alii 2014). The expansion of rural site analyses over the last decade now makes it possible to propose a first comparative approach, despite a still strong imbalance between these two areas.

The most recent synthesis of carpological data from the ancient and medieval Iberian Peninsula indicates the existence in southern Catalonia of six studies of rural plain sites, located between the current provinces of Girona and Barcelona. The corpus covers a chronology from the 7 th to the 13 th century AD, with the 9 th -11 th centuries being those documented by the largest number of sites (fig. 9). A total of 55 samples were analyzed, collecting 4 045 carporests, including 25 taxa considered to be cultivated or harvested: 9 cereals, 6 legumes, 2 vegetables, 8 fruit plants, one oilseed and one aromatic.

The compilation of data from rural plains sites on either side of the Pyrenees shows that a common agro-horticultural heritage has been exploited (fig. 10). The main species thus seem to be the same, particularly regarding cereals (hulled barley, naked wheat, millets, rye, oats), legumes (faba beans, lentils, peas, vetch) and some fruit plants (vines, fig trees). However, the southern part of the country has a greater diversity, particularly in cereals (presence of hulled wheat, einkorn and emmer, naked barley) and legumes (bitter vetch, chickpea). In the current state of research on textual and carpological documentation, it would seem that hulled wheat, naked barley and bitter vetch, did not form part of the agro-horticultural spectrum exploited in medieval Roussillon [START_REF] Puig | Les campagnes roussillonnaises au Moyen Age : dynamiques agricoles et paysagères entre le XII ème et la première moitié du XIV ème siècle[END_REF][START_REF] Drendel | ans d'agriculture en Roussillon, Productions végétales et terroirs protohistoriques, antiques et médiévaux, Éditions Mergoil[END_REF], perhaps marking here a regional specificity.

Concerning chickpea, it is disturbing that the archaeological sites of Roussillon have not delivered any, although they are mentioned in the leudes (Perpignan, Thuir, Collioure) [START_REF] Puig | Les campagnes roussillonnaises au Moyen Age : dynamiques agricoles et paysagères entre le XII ème et la première moitié du XIV ème siècle[END_REF], and that they are attested by carpology in southern Catalonia (PEÑA-CHOCARRO et alii 2018) as well as in Languedoc and Provence between the 8 th and the 11 th centuries [START_REF]Les plantes exploitées en France au Moyen Age d'après les semences archéologiques, Flaran 12, Plantes et cultures nouvelles en Europe occidentale au Moyen Age et à l'époque moderne[END_REF](RUAS , 2005)).

There is a significant difference between the two studied areas for fruit plants and technical/oilseed crops, which do not seem to share any common species other than grapevine and fig tree. These results should be considered with caution; the punctual nature of the discoveries of fruit remains in the studied rural samples should not lead to an over-interpretation of the data, as some taxa recorded in southern Catalonia appeared in northern Catalonia during this period, but only in certain foothills or high altitude areas. This is the case in particular of strawberry, raspberry and almond, recorded in levels of the 11 th -13 th centuries of the Château des Angles in Capcir [START_REF] Poisson | Glanes et cultures médiévales en haute montagne. Réflexions autour d'une cabane d'estive à Enveig et du château des Angles (Pyrénées-orientales)[END_REF], and peach, present in 9 th -10 th centuries levels of the castrum of Ultréra, located in the Alberes foothills (ROS 2020). As far as technical/oilseed plants are concerned, there is a total absence of carpological mentions of hemp in southern Catalonia during historical periods, and conversely a total absence of camelina (Camelina sativa) in northern Catalonia. Flax is present in both areas, but is currently only recorded in urban areas in southern Catalonia (PEÑA-CHOCARRO et alii 2018).

Overall, this first assessment offers mixed results. While the agro-horticultural exploited heritage seems to be the same for all the rural plain sites, variations within the secondary species exploited can be observed on both sides of the Pyrenees. Due to the disparity of the data, it is difficult to qualify these variations; it is too early to qualify them as specific, and to attribute

CONCLUSION

The first assessment carried out (ROS et alii 2016) made it possible to sketch a first portrait of the main agricultural plant resources of northern Catalonia, by comparing the available carpological data with textual sources. The new carpological corpus, increased and above all based on quantified data, makes it possible to bring out new results and also new questions regarding agro-horticultural production in this region.

It can be seen that the food-producing agro-horticultural base of Roussillon fully emerged during the first centuries of the Middle Ages and evolved little over time, the main species exploited, whether cereals, legumes, fruit plants or technical/oilseed plants, remaining the same.

The frequencies established make it possible to confirm the importance of hulled barley, naked wheat and grapevine in the peasant sphere, as well as that of olive tree, whose absence in the rural contexts of southern Catalonia raises questions. The changes in the rural world, particularly through the emergence of a new network of rural farms during the 9 th -10 th centuries, do not seem to have had any direct impact on the choice of species exploited; they may, however, have had an effect on the morphology of the terroirs, the archaeobotanical documentation not being able to highlight this at the moment. An evolution of the agri-food heritage seems to have occurred in the last centuries of the period under consideration (13 th -14 th centuries), resulting in the integration of new plants, and in particular, in this case, of spinach.

In the case of spinach, this integration seems to happen quickly, unlike those of perennial species, such as apricot or orange, which seem to occur through different pathways. The differences in treatment between these three species can have multiple origins, related to the social, symbolic or economic status of these plants, but also to the practices associated with their cultivation, annual plants such as spinach being less complex to cultivate than certain "exotic" perennial species requiring particular know-how (use of irrigation, grafting, adaptation to local climate, etc.). The integration of new species also raises the question of the mechanism for its implementation. In the case of the orange tree, it seems to be governed by fashion effects: the exotic and new fruit, first appearing on urban markets before the tree enters the royal gardens, then those of a knight, before passing into the peasant sphere; the question then arises of the transmission of agricultural knowledge and practices related to the cultivation of the species.

Finally, a comparison of the data obtained in medieval Roussillon with those available for southern Catalonia reveals the existence of certain homogeneity regarding the agro-horticultural base exploited on either side of the Pyrenees; with variations in secondary species to be confirmed in future work. If for the same period a similar diversity is recorded in medieval Mediterranean France, it is difficult for us to make comparisons with other parts of the western Mediterranean, for example in Spain, because of the excessive disparities that currently exist in

  Mentions of other fruit plants are more sporadic. The fig tree (Ficus carica) is present in 4 sites (5 contexts) and the blackberry (Rubus fruticosus) in 3 sites (4 contexts). The remains of the other fruit plants, hazelnut (Corylus avellana), stone pine (Pinus pinea), plum (Prunus domestica), hawthorn (Crataegus sp.), oak (Quercus sp.), appear only occasionally, each in a single context, in the form of few fragments of shells, stones or cotyledons.

  , barley is recognised by late sources as a spring cereal(PUIG 2003: 228), while the textual sources of Languedoc indicate in the 12 th century the existence of winter (escourgeon) and spring (paumelle) barley(DURAND 1998: 313).The common and foxtail millets occupy a special place in the corpus. Little referenced in Roussillon's written sources, they are among the oldest cereals mentioned in the documentation, from the 10 th century onwards (ROS et alii 2016). In Roussillon, they flourished significantly from the first centuries of the Middle Ages, with common millet becoming the third most frequent cereal in carpological samples (ROS et alii 2020), at least until the 14 th century. Being just as versatile as barley, the carpological corpus does not allow us to determine the role played by the common and foxtail millets in Roussillon farming practices (human and/or animal food).

  textual sources in Conflent (Taurinya), Ribéral (Ille, Néfiac) and Argelès-sur-Mer (PUIG 2003), and recognised by carpology in the high Capcir and Cerdanya mountains (Ruas and Rendu 2005). Although carpological occurrences of oats multiplied in the Early Middle Ages in the western Mediterranean (for ex. RUAS 2005, 2010; PEÑA-CHOCARRO et alii 2018), its status remains unclear; although its exploitation in the region is documented by animal feed legislation (ROS et alii 2016).

  them to local economic, cultural or environmental adaptations. While the agro-horticultural spectrum of southern Catalonia does not yet offer any new features compared to what is known in this region for the ancient period (PEÑA-CHOCARRO et alii 2018), it is important to keep in mind the nascent nature of the studies carried out, as only six rural medieval sites have been the subject of carpological analyses.

Fig. 1 :

 1 Fig. 1: Plant foods exploited and traded in medieval northern Catalonia, based on textual sources (acts of practice, royal ordinances, commercial archives, terrier censuses) and carpological remains (10 th -15 th centuries): data as of 2014 (Ros et al. 2016). Conception : J. Ros

Fig. 4 :Fig. 5 :Fig. 6 :Fig. 8 :Fig. 9 :Fig. 10 :

 4568910 Fig. 4: Identification and enumeration of carpological remains od cereals of the corpus (sem. = seeds; fg. = fragment; X = taxon present)

Collective Research Project «Villages d'hier, villages d'aujourd'hui, Plaine du Roussillon», directed by O. Passarrius and A. Catafau.

The work took place partly at the archaeobotanical platform of the UMR 7209 (Muséum national d'Histoire naturelle de Paris) in Paris and partly at the carpological platform of the UMR 5554 (Institut des Sciences de l'Evolution, Université de Montpellier) in Montpellier.

For vegetables, it is often the vegetative parts that are harvested and consumed before the fruits are formed ; they are therefore rarely recorded in archaeological sites.

Leudaire of Collioure 1298. ADPO 1B69 f°7-12. Leude de terre de Collioure, 1300, ADPO 1B69, f°4r-5v°.

Leudaire of Collioure 1298. ADPO 1B69 f°7-12. Leude de terre de Collioure, 1300, ADPO 1B69, f°4r-5v°.

 7 This would also favour the interpretation of pomers as a citrus fruit and a fruit that is not native to the northwesternMediterranean. PUIG 2006

The realization of a radiocarbon dating has been recommended and is currently awaiting completion.

Acknowledgements

This research could not have been carried out without the work carried out over many years by various institutions, companies and colleagues working in Roussillon, in particular the Departmental Archaeological Service of the Pyrénées-Orientales, the Inrap and the company Acter, as well as the many archaeologists whose investment was essential to constitute the substantial corpus of studied samples. We would also like to thank Marie-Pierre Ruas and Christophe Vaschalde for the scientific exchanges that have enriched this work, as well as Pietro Chiera for his advices.

this research theme. If in the coming years this research on the Catalan rural world is to be continued, it will be necessary to carry out, in parallel, the study of urban contexts, in order to be able to determine whether there are significant and quantifiable differences in terms of the agri-food spectrum consumed and exploited.