Justice Muvengwi
email: justicemuvengwi@gmail.com

Herve Fritz

Monicah Mbiba

Hilton G T Ndagurwa

Land use effects on phylogenetic and functional diversity of birds: Significance of urban green spaces

Keywords:

Species richness per sampling point was high in Harare compared with Chivero Park. • Bird functional diversity was higher in Harare than Chivero Park. • Phylogenetic diversity was in higher in Chivero Park than Harare.

• Proportional species richness for the different functional groups was similar between sites.

Introduction

Urbanization has profound effects on biodiversity. It has been singled out as one major contributor to biotic homogenization [START_REF] Mckinney | Urbanization as a major cause of biotic homogenization[END_REF]. However with proper planning during development urban landscapes can conserve biodiversity. The urban landscape matrix house a great deal of species both native and nonnative [START_REF] Aronson | A global analysis of the impacts of urbanization on bird and plant diversity reveals key anthropogenic drivers[END_REF][START_REF] Ives | Cities are hotspots for threatened species[END_REF]Lepczyk et al., 2017;Lepczyk, Aronson et al., 2017). Urban green spaces comprise a range of habitat types that cross a continuum from intact remnant patches of native vegetation, brownfields, gardens, and yards, to essentially terraformed patches of vegetation that may or may not be representative of native community associations (Lepczyk, Aronson et al., 2017). All these urban green spaces play several ecosystem functions. Green spaces reduce surface runoff because most of the rainwater infiltrates, however, the development of tarred roads and pavements reduces permeable surfaces in urban communities which increase surface runoff and urban flooding [START_REF] Armson | Urban forestry & urban greening the effect of street trees and amenity grass on urban surface water runoff in[END_REF]. Urban vegetation sequesters carbon thereby reduce the amount of carbon from industries and automobiles [START_REF] Vailshery | Urban Forestry & Urban Greening Effect of street trees on microclimate and air pollution in a tropical city[END_REF][START_REF] Yang | The urban forest in Beijing and its role in air pollution reduction[END_REF]. Urban green spaces also provide cultural services such as, aesthetics, recreation and heritage which are important for human wellbeing (Threlfall & Kendal, 2016). Urban green spaces are critical habitats to support biodiversity, but we still have a limited understanding of their ecology and how they function to conserve biodiversity at local and landscape scales across multiple taxa (Lepczyk, Aronson et al., 2017;[START_REF] Lepczyk | Global patterns and drivers of urban bird diversity[END_REF]. Many cities in Africa lack studies on how urban green spaces contribute to biodiversity conservation [START_REF] Aronson | A global analysis of the impacts of urbanization on bird and plant diversity reveals key anthropogenic drivers[END_REF][START_REF] Alamo | Global loss of avian ´ evolutionary uniqueness in urban areas[END_REF] ´ & Morelli, 2017; La [START_REF] Sorte | The phylogenetic and functional diversity of regional breeding bird assemblages is reduced and constricted through urbanization[END_REF][START_REF] Mckinney | Urbanization as a major cause of biotic homogenization[END_REF].

One way of understanding the extent to which urban green spaces contribute to biodiversity is to compare them to regional areas (e.g. East Africa, West Africa, North Africa or Southern Africa) where they are located. In a study focusing on birds, compared to regional assemblages, urban assemblages contained lower phylogenetic diversity and lower phylogenetic beta-diversity (La [START_REF] Sorte | The phylogenetic and functional diversity of regional breeding bird assemblages is reduced and constricted through urbanization[END_REF]. Similarly, urban-rural gradient research has shown that increased urbanization leads to decreased species richness [START_REF] Lepczyk | Human impacts on regional avian diversity and abundance[END_REF] but an increase in total avian biomass due to the dominance of a few urban dwelling species [START_REF] Clergeau | ¨ Avifauna homogenisation by urbanisation: Analysis at different European latitudes[END_REF][START_REF] Garaffa | Bird community responses along urban-rural gradients: Does the size of the urbanized area matter?[END_REF]. Within cities, bird species density was highest in cities with the lowest proportion of urban land cover [START_REF] Aronson | A global analysis of the impacts of urbanization on bird and plant diversity reveals key anthropogenic drivers[END_REF], indicating that the provision of green space at the city scale is crucial to bird species conservation in cities [START_REF] Chace | Urban effects on native avifauna: A review[END_REF][START_REF] Evans | Habitat influences on urban avian assemblages[END_REF]. For example, there is evidence that remnant patches of intact vegetation within urban areas retain macroecological patterns similar to those found in patches of intact vegetation outside urban areas [START_REF] Pautasso | Global macroecology of bird assemblages in urbanized and semi-natural ecosystems[END_REF]. In developing countries, there is rapid expansion of urban development, therefore understanding the drivers of biodiversity in urban green spaces is valuable to global biodiversity conservation [START_REF] Aronson | Biodiversity in the city: Key challenges for urban green space management[END_REF]. Indeed, biodiversity studies that target beyond species richness have the potential to inform the preservation of health, functioning ecosystem [START_REF] Cadotte | Beyond species: Functional diversity and the maintenance of ecological processes and services[END_REF]. In order to achieve this we considered indices that targeted functional [START_REF] Bregman | Using avian functional traits to assess the impact of land-cover change on ecosystem processes linked to resilience in tropical forests[END_REF][START_REF] Chapman | Contrasting impacts of landuse change on phylogenetic and functional diversity of tropical forest birds[END_REF] and phylogenetic diversity [START_REF] Chapman | Contrasting impacts of landuse change on phylogenetic and functional diversity of tropical forest birds[END_REF][START_REF] Jarzyna | Detecting the multiple facets of biodiversity[END_REF][START_REF] Lopez | A new framework for inferring community assembly processes using phylogenetic information, relevant traits and environmental gradients[END_REF].

Functional diversity (FD) is the sum of branch lengths in a dendrogram generated from functional trait differences [START_REF] Petchey | Functional diversity (FD), species richness and community composition[END_REF], 2006), and can be better proxy for explaining ecosystem functioning than classical measures of taxonomic diversity (e.g. species richness, Simpson's diversity index) [START_REF] Cadotte | Beyond species: Functional diversity and the maintenance of ecological processes and services[END_REF]. High dissimilarity between species result in higher FD, which, therefore, provides an index of niche complementarity and the diversity of ecological interactions present within communities [START_REF] Cadotte | Beyond species: Functional diversity and the maintenance of ecological processes and services[END_REF][START_REF] Cadotte | Phylogenetic diversity promotes ecosystem stability[END_REF][START_REF] Chapman | Contrasting impacts of landuse change on phylogenetic and functional diversity of tropical forest birds[END_REF]. The alternative metric of FD, phylogenetic diversity (PD), measures the evolutionary relatedness among species in a community. PD is defined as the total phylogenetic distance among two or more species [START_REF] Faith | Conservation evaluation and phylogenetic diversity[END_REF], explicitly measuring species differences rather than species numbers or traits. Phylogenetic diversity is inversely proportional to the evolutionary relatedness of the species, and higher PD is obtained when species are more distantly related [START_REF] Venail | Species richness, but not phylogenetic diversity, influences community biomass production and temporal stability in a reexamination of 16 grassland biodiversity studies[END_REF]. Greater PD and FD have been found to be correlated with higher ecosystem functioning, stability and productivity compared with species richness [START_REF] Cadotte | Beyond species: Functional diversity and the maintenance of ecological processes and services[END_REF][START_REF] Cadotte | Phylogenetic diversity promotes ecosystem stability[END_REF]. Our understanding of how biodiversity metrics such as PD and FD differ between urban areas and protected areas remains limited (but see. La [START_REF] Sorte | The phylogenetic and functional diversity of regional breeding bird assemblages is reduced and constricted through urbanization[END_REF][START_REF] Weideman | Land cover change homogenizes functional and phylogenetic diversity within and among African savanna bird assemblages[END_REF]. Indeed, the effect of urbanization on phylogenetic diversity remains unclear [START_REF] Morelli | Evidence of evolutionary homogenization of bird communities in urban environments across Europe[END_REF].

We considered birds because they have been shown to be good indicator species in studies considering the effect of urbanization on ecosystems (Iba´nez- ˜ Alamo ´ et al., 2017;[START_REF] Suri | Landscape and Urban Planning More than just a corridor: A suburban river catchment enhances bird functional diversity[END_REF]. Furthermore, the ecology of birds is well understood [START_REF] Edwards | Selective-logging and oil palm: Multitaxon impacts, biodiversity indicators, and trade-offs for conservation planning[END_REF][START_REF] Fontana | How to manage the urban green to improve bird diversity and community structure[END_REF], the link between foraging guilds and ecological functioning is relatively well established [START_REF] Suri | Landscape and Urban Planning More than just a corridor: A suburban river catchment enhances bird functional diversity[END_REF][START_REF] Wenny | Perspectives in ornithology the need to quantify ecosystem services provided by birds[END_REF], their phylogeny has been well established [START_REF] Hackett | A phylogenomic study of birds reveals their evolutionary history[END_REF][START_REF] Jetz | The global diversity of birds in space and time[END_REF] and they respond quickly to changes in habitat and plant community structure [START_REF] Chapman | Contrasting impacts of landuse change on phylogenetic and functional diversity of tropical forest birds[END_REF][START_REF] Hughes | The effects of tropical secondary forest regeneration on avian phylogenetic diversity[END_REF]. Our research gap is whether urban green spaces can support functional and phylogenetic diversity of birds comparable to regional protected areas. In order to achieve this aim we developed the following objectives: (i) to determine bird species abundance, richness and diversity between a protected area and urban green spaces (ii) to determine functional and phylogenetic alpha and beta diversity of birds in green spaces in Harare and Chivero Park. We expected urban green spaces to maintain functional and phylogenetic diversity that is lower to that of Chivero Park since fewer species (urban exploiters) have been observed to benefit from cities (Iba´nez- ˜ Alamo et al., 2017;[START_REF] Sorte | The phylogenetic and functional diversity of regional breeding bird assemblages is reduced and constricted through urbanization[END_REF] ´ 2018).

Materials and methods

Description of study sites

The study was carried out in Harare (18 • 00 ′ S, 31 • 15 ′ E) the capital city of Zimbabwe and Chivero Park (17 • 90 ′ S, 30 • 79 ′ E) south west of Harare (Fig. 1). Rainfall varies between 650 and 850 mm and 700-830 mm for Harare and Chivero Park, respectively. The rainy season span between November and March. Harare and Chivero Park experience hot wet season from November to April, a cool dry season from May to July and a hot dry season from August to October [START_REF] Mbiba | Bird species assemblages differ, while functional richness is maintained across an urban landscape[END_REF][START_REF] Muvengwi | The role of urban schools in biodiversity conservation across an urban landscape[END_REF]. The area between Harare and Chivero Park comprise of commercial farms. The vegetation of Chivero Park is of miombo, characterized by Brachystegia and Julbernardia sp. (Caesalpinioideae). In Harare, we sampled six green spaces, two urban gardens, Harare gardens (HG: 20 ha of mixed exotic and indigenous trees), Africa Unity Square (AUS: 3 ha of exotic trees), Harare Golf Course (HRGC: 86 ha of mainly indigenous trees of the miombo type), Cleveland Park (CL: 273 ha of miombo woodland and a small dam), Mukuvisi Woodlands (MW: 262 ha Bird foraging guilds that were used to put all the birds that were recorded in this study [START_REF] Sekercioglu | Increasing awareness of avian ecological function[END_REF][START_REF] Suri | Landscape and Urban Planning More than just a corridor: A suburban river catchment enhances bird functional diversity[END_REF].

Foraging Group Definition

Insectivores Insect-eating birds

Grazers Feeding on grass Frugivores

Birds that feed on fruits and the seeds from the fruits pass through their digestive tracts deposited in other areas Granivores Seed-eating birds Raptors Birds of prey Nectarivores Birds that pollinate plants when feeding on nectar Scavengers Feeding on carrion material or waste of miombo woodland and a perennial river) and Harare botanical gardens (HBG: 74 ha of miombo woodland) (Fig. 1, Appendix A).

Data collection/Sampling protocol

Field surveys were conducted between December 2018 and February 2019, a time when migrant species are around, and most species are breeding. A total of 60 sampling points were surveyed between Harare and Chivero Park, thirty points at each site. Sampling points were randomly marked considering a minimum distance of at least 300 m spacing between them to avoid pseudo-replication ensuring statistical independence [START_REF] Van Rensburg | Biotic homogenization and alien bird species along an urban gradient in South Africa[END_REF]. Surveys were conducted early morning during the first 3.5 h after sunrise, a period of high bird activity [START_REF] Suri | Landscape and Urban Planning More than just a corridor: A suburban river catchment enhances bird functional diversity[END_REF]. Recording at each point involved a five minutes habituation time (a decrease in response of birds to human presence) which was followed by a 15 min counting time of all the birds in a radius of 150 m [START_REF] Suri | Landscape and Urban Planning More than just a corridor: A suburban river catchment enhances bird functional diversity[END_REF]. Our point counts were conducted by one observer. Sampling points were visited in a random order between Harare and Chivero Park. All the bird species that were seen or heard within the radius were recorded. We classified bird species as threatened with extinction if they were categorized as critically endangered (CR), endangered (EN) or vulnerable (VU) under the IUCN Red List in their native range, otherwise they were considered under least concern (LC) (IUCN, 2011).

Phylogenetic tree construction and functional grouping of birds

We generated 1000 trees based on "Hackett All Species" backbone, because it uses a more extensive genomic scope of loci in the phylogeny construction [START_REF] Jetz | The global diversity of birds in space and time[END_REF][START_REF] Ke | Landscape heterogeneity shapes taxonomic diversity of non-breeding birds across fragmented savanna landscapes[END_REF]. We applied the Maximum Clade Credibility Tree analysis (MCCT, programme "BEAST 2", [START_REF] Bouckaert | BEAST 2: A software platform for bayesian evolutionary analysis[END_REF] to reduce the 1000 subset trees to one tree that had maximal phylogenetic support. We used eight functional traits, namely body mass, body length, culmen, tail, tarsus and wing length (morphometric traits), clutch size (reproductive trait) and foraging guilds (Table 1; Appendix I). Some bird species were falling in more than one foraging guild and were assigned to more than one group using 1 to indicate presence in a group and a 0 for absence (Table 1 Sekercioglu, 2006;[START_REF] Suri | Landscape and Urban Planning More than just a corridor: A suburban river catchment enhances bird functional diversity[END_REF][START_REF] Weideman | Land cover change homogenizes functional and phylogenetic diversity within and among African savanna bird assemblages[END_REF]. The foraging guilds are defined in Table 1.

Phylogenetic and functional α-diversity

To estimate phylogenetic diversity (PD), we used phylogeny of the world's birds [START_REF] Jetz | The global diversity of birds in space and time[END_REF]. Phylogenetic alpha diversity was calculated using Faith's PD [START_REF] Faith | Conservation evaluation and phylogenetic diversity[END_REF]. We used the function pd in the picante package in R [START_REF] Kembel | Picante: R tools for integrating phylogenies and ecology[END_REF]. Phylogenetic diversity (PD) measures the relatedness of species in evolutionary terms across community clades [START_REF] Hensley | Effects of urbanization on native bird species in three southwestern US cities[END_REF].

We calculated the FD and equivalent PD for each sampling point using a directly related method to Faith's PD [START_REF] Petchey | Functional diversity (FD), species richness and community composition[END_REF]. First a trait matrix was used to create a distance matrix using the gowdis from phylopic.org on 20 July 2020. function in FD package. A dendrogram that represents similarity/ dissimilarity of species according to their traits was then constructed from the distance matrix [START_REF] Swenson | Functional and Phylogenetic Ecology[END_REF]. The dendrogram was then transformed into a phylogenetic object and the PD function was applied in the picante package in order to calculate the FD [START_REF] Swenson | Functional and Phylogenetic Ecology[END_REF]. We calculated alpha functional diversity (FD) using the function pd in picante on the phylogenetic object obtained from the dendrogram.

Because of the high correlation between species richness and the measures of phylogenetic and functional diversity, we applied null models to assess the extent to which communities are over-or under-dispersed. We generated null distributions of phylogenetic and functional diversity indices for each site by shuffling the full species by site community matrix of all species found in the study area 999 times maintaining species occurrence frequency and sample species richness. We compared the observed phylogenetic and functional diversity to the mean of the null distribution by calculating a standardized effect size (SES) using the following equation:

Phylogenetic and functional β-diversity

In order to understand the contribution of our two study sites to regional species pool, we applied β-diversity analysis within and between the two study sites. For within site, β-diversity was compared between sampled points within a site (Harare and Chivero Park), and for between sites (Harare-Chivero Park), we compared all sampled points in one site to all the sampled points in the other site [START_REF] Weideman | Land cover change homogenizes functional and phylogenetic diversity within and among African savanna bird assemblages[END_REF]. We calculated functional and phylogenetic β-diversity using the betapart package [START_REF] Baselga | Betapart: An R package for the study of beta diversity[END_REF][START_REF] Baselga | Partitioning the turnover and nestedness components of beta diversity[END_REF]. The PhyloSor index was used to calculate phylogenetic beta diversity (βPD). It is similar to Sorenson's index, but substitutes the unique and shared species with unique and shared phylogenetic branch length and represents the amount of PD shared between sites. This was converted to a dissimilarity measure (1 -PhyloSor). The same procedure was used to calculate functional beta diversity (βFD) but using the functional dendrogram instead of the phylogeny. Standardized effect sizes (SES) for β-diversity were calculated using the formula used for alpha diversity metrics.

Phylogenetic signal of morphometric, reproductive and feeding functional traits

We calculated phylogenetic signal of all the seven binary foraging guild traits using D [START_REF] Fritz | Selectivity in mammalian extinction risk and threat types: A new measure of phylogenetic signal strength in binary traits[END_REF], by scaling the observed sum of sisterclade differences with the mean values of the two expected ∑ distributions as follows ( ∑ ∑ Fritz ∑ & Purvis, 2010 ∑ ): D = [ dobs -mean ( db)]/[mean( dr)mean( ∑ db)], where dobs is the observed sum of sister-clade differences, ∑ db is the sum expected under Brownian evolution and dr are the sum of sisterclade differences expected for a Fig. 2. Phylogeny of the 93 bird species that were recorded in this study. The tree was pruned from the most comprehensive dated phylogeny for birds (Hackett all species) backbone [START_REF] Jetz | The global diversity of birds in space and time[END_REF]. Taxonomic orders of birds with more than two species were highlighted in different colors. Bird silhouettes were downloaded random phylogenetic pattern. Phylogenetic signal of continuous traits was calculated using Blomberg's K [START_REF] Blomberg | Testing for phylogenetic signal in comparative data: Behavioral traits are more labile[END_REF] in picante package [START_REF] Kembel | Picante: R tools for integrating phylogenies and ecology[END_REF].

Statistical analyses

Data were tested for normality and homogeneity of variance before analysis. Alpha diversity metrics (species richness, species abundance, Shannon Wiener index, PD, and FD) were compared between Harare and Chivero Park using independent t-test. One-way analysis of variance (ANOVA) was applied to test for variation in functional and phylogenetic beta-diversity metrics together with the respective standardized effect size (SES). Significant tests were further subjected to a Tukey Honest Difference Test (TukeyHSD) when p-value was < 0.05. One sample t-tests were applied to test if the standardized effect sizes were significantly different from null expectation of zero. False discovery rate for t-tests was controlled for following the procedure in [START_REF] Benjamin | The control of the false discovery rate in multiple testing under dependency[END_REF]. Since birds were sampled using avian point count, we used Mantel's test to calculate patterns of spatial autocorrelation for Harare and Chivero separately. The Mantel test can be used to examine relationships between multivariate dissimilarity matrices and a matrix of their geographic positions, and determines spatial dependence at different distance classes [START_REF] Borcard | Numerical ecology with R[END_REF]. The correlogram produces r coefficients between -1 and 1, where 1 is completely spatially dependent and -1 spatially independent.

Results

A total of 18 bird orders, 48 families, and 93 species were recorded at the two study sites (Fig. 2). Species richness for Chivero Park (72) was greater than that for Harare (66), with 27 and 21 species being unique to each site, respectively. Bird abundance was significantly higher (W = 172, p < 0.0001) per sampling point in Harare compared with Chivero (Fig. 3a). Species richness per sampling point was also significantly higher (t = -2.26, df = 57.85, p = 0.027) in Harare compared with Chivero (Fig. 3b). Although species richness and abundance per sampling point were higher in Harare compared with Chivero, Shannon Wiener index per sampling point did not vary significantly between the two sites (W = 361, p = 0.19) (Fig. 3c).

The most bird rich order was Passeriformes, containing almost half of all the species that were recorded (Fig. 2). Harare and Chivero had each two unique bird orders, Apodiformes and Coliiformes and Psittaciformes and Gruiformes, respectively (Appendices B and C). Passeriformes constituted more than half of the species that were occurring in Harare urban green spaces. The relative species richness in the different functional groups for Harare and Chivero Park were similar to those recorded at national and regional level ( χ 2 = 29.056, df = 24, p-value = 0.218, Appendix D).

Phylogenetic diversity was significantly higher (t = -2.13, df = 56.42, p = 0.038) in Harare than Chivero (Fig. 4a). Similarly, Harare had significantly higher FD (t = -3.51, df = 57.98, p < 0.001) than Chivero (Fig. 4b). There was no significant difference in SESPD (t = 0.2252, df = 55.517, p-value = 0.8226) and SESFD (t = -1.7504, df = 57.153, pvalue = 0.08541) between Harare and Chivero (Fig. 4 c & d, respectively).

Phylogenetic and functional beta diversity

There was a significant difference (F2,2637 = 398.2, p < 0.0001) in βPD between Harare, Chivero and Harare-Chivero. A posthoc test showed that Harare-Chivero beta-diversity was higher than that for both Chivero and Harare (Fig. 5a). Functional beta diversity varied significantly (F2,2637 = 536.3, p < 0.0001) between, Harare, Chivero and Harare-Chivero. A posthoc test showed that Harare-Chivero beta-diversity was higher than that for both Chivero and Harare (Fig. 5b). The standardized effect size for phylogenetic beta-diversity (SESβPD) varied significantly (F2, 2637 = 464.3, p <0.0001). Posthoc test showed that Chevero, Harare and Harare-chivero were all different (Fig. 5c). Harare-Chivero had significantly higher standardized effect size for functional beta-diversity (SESβFD) across sites (F2,2637 = 528.6, p < 0.0001; Fig. 5d).

Phylogenetic signal

All the bird feeding guilds did not differ significantly from the Brownian expectation (D = 0), except for nectarivores. Even those that differed significantly from the random expectation such as insectivores and raptors, they did not differ significantly from the Brownian expectation (Table 2). Only nectarivores differed significantly from the Brownian expectation (Table 2). All continuous traits showed a phylogenetic signal (Table 2).

Spatial autocorrelation

The test results for both Harare and Chivero are non-significant (r = 0.016, p = 0.383; r = 0.017, p = 0.399, respectively), leading to the conclusion that closer samples are not more similar.

Discussion

Our expectation that Chivero Park has higher bird species richness, abundance, phylogenetic and functional diversity than Harare was not supported. Although not significantly different, our results largely indicate that at beta scale bird functional diversity was higher in Harare while no difference was recorded for phylogenetic diversity between the two sites. Two bird orders were unique to each site, Apodiformes [Little Swift (Apus affinis) and African Palm-Swift (Cypsiurus parvus) urban specialists] and one species under Coliiformes, the Speckled Mouse-bird (Colius striatus) were unique to Harare, while Psittaciformes Meyer's Parrot (Poicephalus meyeri) and Gruiformes Black crake (Amaurornis flavirostra) a water bird were only occurring at Chivero Park. Proportional species richness for the different foraging groups did not differ between our two study sites, and between these two sites and those at national and regional level. The higher species abundance and richness in the urban green spaces observed here is similar to what was observed in suburban sites in Finland and Canada compared to periurban [START_REF] Clergeau | Are urban bird communities ¨ influenced by the bird diversity of adjacent landscapes[END_REF]. [START_REF] Clergeau | Are urban bird communities ¨ influenced by the bird diversity of adjacent landscapes[END_REF] attributed their observations to their study site being in the far north and supplementation of seeds at feeders in urban areas increasing seed eating bird richness. However, increasing species richness or abundance in urban areas could also increase their risks to certain threats such as predation by feral cats or collisions with windows [START_REF] Loss | The impact of free-ranging domestic cats on wildlife of the United States[END_REF][START_REF] Seymour | Caught on camera: The impacts of urban domestic cats on wild prey in an African city and neighbouring protected areas[END_REF][START_REF] Trouwborst | Domestic cats and their impacts on biodiversity: A blind spot in the application of nature conservation law[END_REF][START_REF] Van Doren | Drivers of fatal bird collisions in an urban center[END_REF]. So, there are likely tradeoffs that take place in making urban areas more attractive to birds.

Our findings suggest that future urban developments should endeavour to leave patches of green spaces with native vegetation, establish urban gardens and golf courses within the urban landscape matrix. This suggestion stems from the fact that both FD and PD were high in Harare compared with Chivero Park. Also, Harare had higher species richness per sampling point than Chivero Park. Similarly, the urban matrix had higher FD, PD and species richness than Kruger National Park in a study from South Africa [START_REF] Weideman | Land cover change homogenizes functional and phylogenetic diversity within and among African savanna bird assemblages[END_REF]. Indeed, our findings for FD and PD supports previous studies that observed the significance of preserving urban green spaces in urban development as a way to promote biodiversity [START_REF] Aronson | Biodiversity in the city: Key challenges for urban green space management[END_REF][START_REF] Lepczyk | Global patterns and drivers of urban bird diversity[END_REF]. Although our current study and that of [START_REF] Weideman | Land cover change homogenizes functional and phylogenetic diversity within and among African savanna bird assemblages[END_REF] have shown higher phylogenetic and functional diversity in urban green spaces compared with nearby protected areas, this observation is contradictory to studies that have shown urbanization to be associated with lower phylogenic diversity (Iba´nez- ˜ Alamo ´ et al., 2017;[START_REF] Sorte | The phylogenetic and functional diversity of regional breeding bird assemblages is reduced and constricted through urbanization[END_REF], and differences could have emanated from differences in scales at which these studies have been carried out, local and global, respectively. However, after controlling for species richness, phylogenetic diversity (SESPD) of bird communities although not significantly different from zero, there was a tendency towards biological homogenization in both Harare and Chivero. This observation indicates that sampled points within each site comprised of phylogenetically related species. Indeed, urban environments have been previously reported to suffer from biotic homogenization in some previous studies [START_REF] Clavel | Worldwide decline of specialist species: Toward a global functional homogenization?[END_REF][START_REF] Godet | Dissociating several forms of commonness in birds sheds new light on biotic homogenization[END_REF][START_REF] Reif | Changes in bird community composition in the Czech Republic from 1982 to 2004: Increasing biotic homogenization, impacts of warming climate, but no trend in species richness[END_REF][START_REF] Weideman | Land cover change homogenizes functional and phylogenetic diversity within and among African savanna bird assemblages[END_REF].

The higher FD in Harare than Chivero Park suggests that birds recorded at sampling points in Harare are distributed across a wider range of functional clades than those recorded in Chivero Park. The likely reason why higher functional diversity was recorded in Harare is that it had more large bodied species (Ciconia abdimii, Threskiornis aethiopicus, Falco amurensis, Numida meleagris, Bubulcus ibis and Columba livia) and more lineages of generalist species that have adapted to living in highly urbanized environments for example Little Swift, African Palm-Swift and Pied Crow and these species were occurring in high numbers [START_REF] Clavel | Worldwide decline of specialist species: Toward a global functional homogenization?[END_REF][START_REF] Suri | Landscape and Urban Planning More than just a corridor: A suburban river catchment enhances bird functional diversity[END_REF]. Indeed, Harare had more birds in the order Passeriformes which could have further enhanced functional diversity since they as well fall in several foraging guilds. The dominance of passerines in urban environments has been observed before (La [START_REF] Sorte | The phylogenetic and functional diversity of regional breeding bird assemblages is reduced and constricted through urbanization[END_REF]. Furthermore, the high habitat diversity surrounding the sampled green spaces may enhance functional diversity and help explain this enigma [START_REF] Hagen | Impacts of urban areas and their characteristics on avian functional diversity[END_REF][START_REF] Mbiba | Bird species assemblages differ, while functional richness is maintained across an urban landscape[END_REF]. Relative to native species, the abundance of non-native species in urban areas tends to be higher [START_REF] Lepczyk | Global patterns and drivers of urban bird diversity[END_REF]. After controlling for species richness, species in Harare are over dispersed, while in Chivero they are random. The over dispersion of bird functions in Harare is different from a similar study [START_REF] Weideman | Land cover change homogenizes functional and phylogenetic diversity within and among African savanna bird assemblages[END_REF], where clustering was observed in the urban environment. However, recent evidence suggests that higher functional diversity may result from higher rates of lineage turnover rather than speciation [START_REF] Igea | Angiosperm speciation cools down in the tropics[END_REF]. All the birds that were recorded in the urban green spaces were IUCN Red List least concern designates, which may still mean that a lot more still needs to be done in order to create conducive habitats for such species here. Alternatively, conservation of threatened species can be enforced outside of urban landscapes through law and policy.

Between sites (Harare-Chivero) beta diversity for both functional and phylogenetic diversity was higher compared to within sites (Harare and Chivero). This high turnover in species between the two sites may indicate that urban landscapes produce sufficient heterogeneity that can be important for bird species conservation complementing the protected area matrix leading to higher regional bird diversity [START_REF] Child | Assessing the broad-scale impact of agriculturally transformed and protected area landscapes on avian taxonomic and functional richness[END_REF][START_REF] Fahrig | Is habitat fragmentation bad for biodiversity?[END_REF][START_REF] Ke | Landscape heterogeneity shapes taxonomic diversity of non-breeding birds across fragmented savanna landscapes[END_REF][START_REF] Sorte | The phylogenetic and functional diversity of regional breeding bird assemblages is reduced and constricted through urbanization[END_REF]. After controlling for species richness, functional and phylogenetic β-diversity showed over dispersion between sites (Harare-Chivero). The fact that Chivero Park sampling points were clustered compared with those from Harare for βdiversity is different from what was observed in South Africa where the protected area had higher diversity compared with the urban environment [START_REF] Weideman | Land cover change homogenizes functional and phylogenetic diversity within and among African savanna bird assemblages[END_REF]. There was evidence of biotic homogenization of βdiversity within sites for both phylogenetic and functional diversity, and this is only similar to other studies that were carried in the urban environments (Iba´nez-˜ [START_REF] Alamo | Global loss of avian ´ evolutionary uniqueness in urban areas[END_REF][START_REF] Weideman | Land cover change homogenizes functional and phylogenetic diversity within and among African savanna bird assemblages[END_REF] ´ ). Differences probably emanated from our small sample size which was not repeated across years.

We therefore, ask people to interpret our results with caution.

Our study uses a protected area located near a city to assess how urban green spaces influence phylogenetic and functional diversity of breeding bird assemblages. We show that urban green spaces have the potential to maintain high species richness, abundance, functional and phylogenetic diversity. However, on the other hand protected areas may exhibit functional redundancy and broad-based clade diversity for phylogenetic diversity. Overall, urban green spaces can complement protected areas, thereby improving the national and regional functional and phylogenetic diversity. Although all the functional groups were represented in the urban green spaces as well as in Lake Chivero Park, this study did not record any bird species designated of significant concern in the IUCN Red List.

Funding

Not applicable.

Fig. 1 .

 1 Fig. 1. Map showing location of the study sites, Harare and Lake Chivero Park. Harare gardens (HG), Harare Golf Course (HRGC), Africa Unit Square (AUS), Mukuvisi Woodlands (MW), Harare botanical gardens (HBG) and Cleveland Park (CL).

  the observed PD or FD at a single site subtracting the mean of the PD or FD null distribution divided by the standard deviation of the PD or FD null distribution. Lower values of SES (<0) indicate phylogenetic clustering (i.e. co-occurring bird species are more closely related than expected by chance), whereas higher values (>0) indicate phylogenetic over dispersion (i.e. co-occurring bird species are less closely related than expected by chance).

Fig. 3 .

 3 Fig. 3. Violin plots comparing bird species abundance, richness and Shannon Wiener index at sampled points between Harare and Chivero. Box of the boxplot inside the violins indicate 25%-quartile, median and 75%-quartile from left to right.

Fig. 4 .

 4 Fig. 4. Violin plots comparing bird species phylogenetic diversity (PD), Functional diversity (FD), standardized effect size for PD (SESPD) and standardized effect size for FD (SESFD) between Harare and Chivero. Box of the boxplot inside the violins indicate 25%-quartile, median and 75%-quartile from left to right.

Fig. 5 .

 5 Fig. 5. Box plots comparing phylogenetic beta diversity (a), Functional beta diversity (b), standardized effect size for phylogenetic beta diversity (c) and standardized effect size for functional beta diversity (d) within sites (Harare and Chivero) and between sites (Harare-Chivero). The boxplot indicate 25%-quartile, median and 75%-quartile from bottom going up. The whiskers represent 1.5 × interquartile range (bottom) and 1.5 × interquartile range (top).

Table 1

 1

Table 2

 2 Phylogenetic signal for seven bird foraging traits that we considered in this study. Values of D smaller than 0 are phylogenetically more conserved than under the Brownian model and values of D greater than 1 are phylogenetically over dispersed.

					Culmen length	1.58	0.001
					Tail length	1.63	0.001
	Categorical traits	Bird feeding guilds	D statistic	p-value	Clutch size	0.40	0.002
		Insectivores	0.08	< 0.01
		Frugivores	0.12	<0.01
		Granivores	-0.46	<0.01
		Raptors	-0.30	< 0.01
		Nectarivores	1.11	0.60
		Scavengers	-0.14	0.06
		Grazers	0.44	0.12
	Continuous variables	Continuous trait	Blomberg's K	p-value
		Body mass	3.46	0.001
		Body length	3.31	0.001
		Tarsus length	2.29	0.001
		Wing length	3.13	0.001

Acknowledgements

We would like to thank our field assistant Innocent Magunje for his dedication to the project during data collection. The authors are indebted to the reviewers for their time and effort that allowed us to increase the clarity and quality of our work.

Data availability statement

Upon Acceptance data will be made available from the Dryad Digital Repository.

Appendix A. Supplementary data

Supplementary data to this article can be found online at https://doi. org/10.1016/j.landurbplan.2022.104462.