Pine invasion decreases density and changes native tree communities in woodland Cerrado

ABSTRACT

Background: Invasive plants can negatively impact native communities, but the majority of the effects of these invasions have been demonstrated only for temperate ecosystems. Tropical ecosystems, including the Cerrado, a biodiversity hotspot, are known to be invaded by numerous non-native species, but studies of their impacts are largely lacking.

Aims: Our research aimed at quantifying how Pinus spp. presence and density affected Cerrado plant communities.

Methods: We sampled areas invaded and non-invaded by Pinus spp. to determine if pine invasion affected native tree richness, diversity, evenness, and density. We also evaluated if community composition differed between invaded and non-invaded sites.

Results: We found invaded plots had lower native tree densities than non-invaded plots and that Pinus spp. invasions changed native tree communities by reducing native species abundances.

Conclusion: Invasive pines had negative impacts on the native Cerrado tree community by reducing native plant density and changing species abundances. Reduced density and abundance at early invasion stages can result in reduction in biodiversity in the long term.     

Patterns of woody plant invasion in an Argentinean coastal grassland

Coastal dune grasslands are fragile ecosystems that have historically been subjected to various types of uses and human activities. In Buenos Aires Province (Argentina), these areas are frequently afforested for urban and touristic development. The introduction and subsequent spread of exotic tree species is one of the main threats to conservation of natural grasslands as invasive trees strongly transform their structure and composition. The aim of this study was to identify patterns of woody plant invasion comparing plant communities and environmental variables between invaded and non-invaded areas surrounding the coastal village of Mar Azul, Argentina. Coastal grasslands in this area are being invaded by Populus alba (white poplar) and Acacia longifolia (coast wattle). The height of the saplings and the richness of the accompanying vegetation were evaluated in relation to the distance from the edge of the mature tree patches. Also, the cover, richness and diversity of all species in the invaded and non-invaded areas were measured, as well as soil pH, temperature and particle size. Negative correlations were found between the height of the saplings and distance to mature tree patches in all areas. The richness of the accompanying vegetation was negatively and positively correlated with the distance from the poplar and acacia area, respectively. The most abundant native species was Cortaderia selloana. Less cover, richness and diversity of native plant species and greater soil particle size were found in invaded areas, where the proportion of bare soil was higher. Also, a higher proportion of leaf litter in the invaded areas was registered. The results emphasize the invasive capacity of P. alba and A. longifolia advancing on the native communities and reducing their richness. Knowledge of the impact of invasive woody plants in coastal grasslands is important to design active management strategies for conservation purposes.     

Impact of Parthenium hysterophorus L. invasion on plant species composition and soil properties of grassland communities in Nepal

Parthenium hysterophorus (Asteraceae) is a noxious plant that is considered one of the most invasive species in the world. We studied changes in the composition of plant species and soil properties related to the invasion of P. hysterophorus in three grassland communities of central Nepal. We collected vegetation and soil data along transects that were established in densely invaded to non-invaded areas within homogenous grassland stands. We found significant differences between invaded, transitional and non-invaded plots in species composition and soil properties. There were fewer species in non-invaded than transitional and invaded plots. By P. hysterophorus invasion both native and non-native species were supported or replaced, respectively. The concentrations of soil nitrogen and organic matter were significantly higher in transitional and invaded plots than in non-invaded plots. Soil pH, phosphorus and potassium were highest in the invaded plots, lowest in the non-invaded and intermediate in the transitional plots. Due to changes in above-ground vegetation and below-ground soil nutrient contents, P. hysterophorus invasion is likely to have an overall negative effect on the functioning of the entire ecosystem. Therefore, management of noxious P. hysterophorus is necessary to prevent future problems.     

Impacts of a woody invader vary in different vegetation communities

The impact of an exotic species in natural systems may be dependent not only on invader attributes but also on characteristics of the invaded community. We examined impacts of the invader bitou bush, Chrysanthemoides monilifera ssp. rotundata , in fore and hind dune communities of coastal New South Wales, Australia. We compared invader impacts on vegetation structure, richness of both native and exotic growth forms and community variability in fore and hind dunes. We found that impacts of bitou invasion were context specific: in fore dune shrublands, functionally distinct graminoid, herb and climber rather than shrub growth forms had significantly reduced species richness following bitou invasion. However, in forested hind dunes, the functionally similar native shrub growth form had significantly reduced species richness following bitou invasion. Density of vegetation structure increased at the shrub level in both fore and hind dune invaded communities compared with non-invaded communities. Fore dune ground-level vegetation density declined at invaded sites compared with non-invaded sites, reflecting significant reductions in herb and graminoid species richness. Hind dune canopy-level vegetation density was reduced at invaded compared with non-invaded sites. Bitou bush invasion also affected fore dune community variability with significant increases in variability of species abundances observed in invaded compared with non-invaded sites. In contrast, variability among all hind dune sites was similar. The results suggest that effects of bitou bush invasion are mediated by the vegetation community. When bitou bush becomes abundant, community structure and functioning may be compromised.     

Impacts of Myriophyllum aquaticum invasion in a Mediterranean wetland on plant and macro-arthropod communities

The invasion by alien macrophytes in aquatic ecosystems may produce a strong alteration of the native aquatic vegetation leading to heavy impacts for both plant and faunal native diversity. Myriophyllum aquaticum is an aquatic plant native of Southern America, invasive in several part of the world. We studied the effects of M. aquaticum invasion on plant and macro-arthropod communities in the canals around a protected wetland in the Mediterranean basin. We sampled plant and macro-arthropod communities in 10 transects in invaded and non-invaded tracts of the canals. We assessed the differences in plant and macro-arthropod species richness, diversity, taxonomic diversity and species composition between invaded and non-invaded habitats by means of univariate and multivariate analyses. Our study shows a significant loss of plant diversity between non-invaded to invaded sites, leading to communities numerically and taxonomically impoverished and highly divergent in the species composition. We also detected significant differences in arthropod species composition between invaded and non-invaded transects. Some taxa such as mosquitoes and malacostraca were more frequent in the M. aquaticum-dominated stands. Furthermore, the study shows a positive relation between invaded habitats and juvenile individuals of the invasive alien crayfish Procambarus clarkii.     

African Grass Invasion in the Americas: Ecosystem Consequences and the Role of Ecophysiology

Clearing of natural vegetation for pastures and the deliberate introduction of African grasses constitute significant threats to the biological diversity of the tropics, subtropics, and warm temperate regions of the Americas. African grasses have escaped from cultivated pastures and revegetated rangeland sites and invaded natural areas at alarming rates. Invaded ecosystems tend to be biotically impoverished and differ markedly from adjacent non-invaded areas in structure and function. Effects of pasture creation and invasion by African grasses on ecosystem processes (transformation and flux of energy and matter) are primarily related to loss of woody species and changes in the fire regime. However, the ecophysiological attributes of the African grasses (e.g. high biomass allocation to leaves, high growth rate, and high leaf-level gas exchange rates) also have important consequences. Here we describe the extent of pasture creation with African grasses and their invasive spread in the New World and review ecological effects of these land-cover changes. We highlight a number of comparative ecophysiological studies within the context of mechanisms responsible for invasion by African grasses and resulting ecosystem change. This revised version was published online in July 2006 with corrections to the Cover Date.     

Green Frogs Show Reduced Foraging Success in Habitats Invaded by Japanese knotweed

Habitat loss is causing amphibian population declines worldwide, so there is increased attention to forces that degrade remaining habitats. Terrestrial habitats surrounding wetlands are critical foraging areas for temperate anurans. We investigated plant community changes in two old fields invaded by Japanese knotweed (Fallopia japonica) and the foraging success of Green frogs (Rana clamitans) in invaded and non-invaded portions of those fields. Within each field, vegetation data were recorded in quadrats located along two transects bisecting the invasion fronts. We placed frogs in ‘foraging buckets’ along transects and measured their change in mass over a 38 h period. There were significant changes in vegetation structure and composition associated with Japanese knotweed invasion. Diverse assemblages of native plants that covered non-invaded plots were absent from areas invaded by Japanese knotweed. There was also a significant change in vegetation architecture between invaded and non-invaded habitats. Change in frog mass declined significantly along transects, with most frogs in non-invaded plots gaining mass and no frogs in invaded plots gaining mass. Most frogs from non-invaded plots but only two from invaded plots defecated shortly after removal from foraging buckets (verification of recent feeding). We hypothesize that Japanese knotweed invasions degrade terrestrial habitat quality for frogs by indirectly reducing arthropod abundance. Nonnative plant invasions may be another factor contributing to amphibian population declines.     

Alien grass disrupts reproduction and post-settlement recruitment of co-occurring native vegetation: a mechanism for diversity decline in invaded forest?

Invasive plants significantly threaten native plant biodiversity, yet the mechanisms by which they drive species losses and maintain their own dominance are poorly known. We examined the effects of alien grass invasion (Stenotaphrum secundatum) on (1) abundance and frequency of occurrence, (2) reproductive effort (flowering) and output (fruit production) and (3) soil seed banks for three focal native plants that are characteristic of endangered coastal forest of south-eastern Australia. First, we sampled and compared the foliage cover abundance and frequency (proportion of sites occupied) of the focal natives across invaded and non-invaded (reference) sites (n = 20). We then intensively sampled reproductive effort and output (range of 5–9 sites per species), and density of propagules within the soil (using a standard glasshouse ‘emergence’ method; n = 26) for each species. Invasion was associated with reduced population sizes of all species within the standing vegetation but did not affect population frequency (i.e. proportion of sites where each species was present). Reproductive effort and output were about 75 % lower at invaded than native sites for all species. However, invasion had no effect on propagule densities of the focal natives within the seed bank, despite the substantial reduction in their reproduction. This indicates that the ultimate driver of population declines across invaded landscapes is post-settlement recruitment limitation from the seed bank (e.g. low rates of germination and seedling survival) rather than a reduction in the arrival and storage of propagules at invaded sites. Removal of Stenotaphrum alone might thus be sufficient to stimulate the recovery of native populations from the seed bank.     

Size, activity and catabolic diversity of the soil microbial biomass in a wetland complex invaded by reed canary grass

Reed canary grass (Phalaris arundinacea, L.) invasion of wetlands is an ecological issue that has received attention, but its impact on soil microbial diversity is not well documented. The present study assessed the size (substrate-induced respiration), catabolic diversity (CLPP, community level physiological profiles) and composition (selective inhibition) of the soil microbial community in invaded (>95% P. arundinacea cover) and in non-invaded areas of a wetland occupied by native species grown either as a mixed assemblage (22 species) or as quasi-monotypic stands of Scirpus cyperinus (74% cover). The study also tested the hypothesis that decomposition of lignin- and phenolics-rich plant tissues would be fastest in soils exhibiting high catabolic diversity. Results showed that soil respiration, microbial biomass and diversity were significantly higher (P?<?0.03; 1.5 to 3 fold) in P. arundinacea-invaded soils than in soils supporting native plant species. Fungal to bacterial ratios were also higher in invaded (0.6) than in non-invaded (0.4) plots. Further, canonical discriminant analysis of CLPP data showed distinct communities of soil decomposers associated with each plant community. However, these differences in microbial attributes had no effect on decomposition of plant biomass which was primarily controlled by its chemical composition. While P. arundinacea invasion has substantially reduced plant diversity, this study found no parallel decline in the size and diversity of the soil microbial community in the invaded areas.     

Focal species diversity patterns can provide diagnostic information on plant invasions

In Europe, coastal sandy habitats are considered highly endangered among those included in the EC Directive 92/43/EEC (Habitats Directive). Among the different threats which affect coastal communities, the spread of alien plants has been claimed to induce changes in community diversity and structure. We therefore set out to analyse diversity patterns of native and focal species (diagnostic and characteristic of coastal dune habitats of European conservation interest) in sandy coastal habitats invaded by Carpobrotus aff. acinaciformis, a widespread alien plant. Focal species are a major conservation target for the Habitats Directive and their decline should be considered a serious threat for the whole habitat. The study was performed in the Central Western coast of Italy. We randomly sampled the vegetation of the holocenic dune by 2 m × 2 m plots. First we split the collected data in two sets: invaded and non-invaded. We compared overall native and focal species richness patterns of the two sets by rarefaction curves. Then, in order to describe the singular aspects of species diversity (e.g. richness, Shannon index, Simpson index, Berger–Parker index), we also compared Rènyi's diversity profiles and we tested the significance of the differences between invaded and non invaded sets using a bootstrap procedure. Rarefaction curves of the non-invaded set rise quickly and reach higher accumulation values than the invaded set, but differences between the two curves were not significant. With respect to Rènyi's profiles, the profile for the invaded dataset was always below the non-invaded one, but differences in diversity were significant only when specifically considering the focal species (Shannon, Simpson and Berger–Parker indices). In the analysed case, the invasion is significantly associated with changes in focal species diversity, instead those differences are not evident on the all native species pool. In the case of recent invasions, a consistent decline on focal species diversity may represent an early alarm sign of diversity loss and may help define specific conservation actions to prevent the decrease of overall diversity.     

Invasive alien plants affect grassland ant communities, colony size and foraging behaviour

Ants are dominant members of many terrestrial ecosystems and are regarded as indicators of environmental changes. However, little is known about the effects of invasive alien plants on ant populations, particularly as regards the density, spatial distribution and size of ant colonies, as well as their foraging behaviour. We addressed these questions in a study of grassland ant communities on five grasslands invaded by alien goldenrods (Solidago sp.) and on five non-invaded grasslands without this plant. In each grassland, seven 100 m² plots were selected and the ant colonies counted. Ant species richness and colony density was lower in the plots on the invaded grasslands. Moreover, both of these traits were higher in the plots near the grassland edge and with a higher number of plant species in the grasslands invaded by goldenrods but not in the non-invaded ones. On average, ant colony size was lower on the invaded grasslands than the non-invaded ones. Also, ant workers travelled for longer distances to collect food items in the invaded areas than they did in the non-invaded ones, even after the experimental removal of some ant colonies in order to exclude the effect of higher colony density in the latter. Our results indicate that invasive alien goldenrods have a profound negative effect on grassland ant communities which may lead to a cascade effect on the whole grassland ecosystem through modification of the interactions among species. The invasion diminishes a major index of the fitness of ants, which is a colony’s size, and probably leads to increased foraging effort of workers. This, in turn, may have important consequences for the division of labour and reproductive strategies within ant colonies.     

Floristic relationships of the woody component in rocky outcrops savanna areas in Central Brazil

Rocky outcrops usually have a peculiar vegetation which differs from that of the surrounding vegetation matrix. In Brazil, a savanna type (cerrado rupestre) is particularly characterized by rocky outcrops and is one of eleven vegetation types which occur throughout Cerrado biome. It has been scarcely studied in detail. Therefore, the aim of this study was to investigate the phytogeographical patterns of the woody species in ten areas of the rocky outcrop savanna in the Brazilian Central Plateau. The difference in spatial distribution of the species was assessed through indicator species and CCA ordination analyses. Ten indicator species showed significantly different distribution. The first axis of the ordination showed association with the edaphic gradient, based on maximum temperature, pH and physical properties of the soils (eigenvalue 0.63). The second axis showed an eigenvalue 0.46, associated with poor rainfall and land declivity. It appears that the woody flora of the rocky outcrop savanna areas of the Brazilian Central Plateau is relatively homogeneous, with low β diversity. Apparently, the size of the woody species populations is what distinguishes the ten investigated areas. Therefore, initiatives and actions for the Cerrado biome conservation must consider not only the size of the protected areas but also that of the populations to be protected, especially the woody species on rocky outcrops.     

Cricket calling communities as an indicator of the invasive ant <Emphasis Type="Italic">Wasmannia auropunctata</Emphasis> in an insular biodiversity hotspot

Invasive species are a major concern for the maintenance of ecosystem services and biodiversity but are difficult to mitigate. Upstream solutions to prevent their impact, including their detection, are needed. Wasmannia auropunctata, an invasive ant living in vagile supercolonies, is especially hard to track and is a major threat for tropical ecosystems and local animal communities. As part of such tropical communities, crickets are sensitive to ecological conditions, easy to collect, detectable and identifiable through their species-specific calls. Here, we evaluated the use of an acoustic community of crickets as an indicator of the presence of W. auropunctata in New Caledonia. We evaluated the dominance of the crickets in the soundscape, describe the cricket community structure and diversity along a shrubland to forest gradient, characterize these cricket communities structure and diversity in the light of ongoing invasion by W. auropunctata, and identify cricket species’ indicators of the invasion. Acoustic recordings collected on 24 sites were described using human-listening and spectrographic visualization. The results demonstrated a clear dominance of the cricket group in the New Caledonian nocturnal soundscapes. Each habitat harbored a specific acoustic cricket community related to specific environmental attributes including vegetation height, daily variation of humidity and temperature. The presence of W. auropunctata was significantly associated with a lower cricket acoustic activity and species richness at night. Of the 19 species detected, four nocturnal species were identified as indicator of non-invaded forests and preforests. This work supports the use of acoustic as an alternative method to detect invasion.     

Relationship between the presence of House Sparrows (<Emphasis Type="Italic">Passer domesticus</Emphasis>) and Neotropical bird community structure and diversity

Invasive exotic species pose an important threat to biodiversity worldwide. However, there is little information on the effects that specific exotic bird species have on native biota. The House Sparrow is an excellent ecological model to evaluate the effect that an invasive exotic species has on native bird communities. Our study describes the relationship of the presence and abundance of House Sparrows with the structure, diversity, and composition of native bird communities in West Mexico. We used two approaches to compare House Sparrow invaded and non-invaded bird communities: (1) at a small geographic-scale that allowed us to evaluate shifts in avian communities with presence of the House Sparrow under similar environmental conditions; and (2) at the landscape-level to evaluate the effect of this species under a scenario of greater environmental heterogeneity. Results from both approaches show that areas invaded by House Sparrows have heavily-dominated avian communities with low species richness, while non-invaded areas exhibit highly-even and species-rich bird communities. Species turnover analysis indicates that the decrease in the number of bird species in House Sparrow invaded areas is caused by species loss, rather than a shift in species composition. Our results indicate that the invasion of an area by the House Sparrow, through synergistic interactions with human activities, determines the composition, structure, and diversity of native bird communities.     

Understory Invasion by <Emphasis Type="Italic">Acacia longifolia</Emphasis> Alters the Water Balance and Carbon Gain of a Mediterranean Pine Forest

In water-limited ecosystems, where potential evapotranspiration exceeds precipitation, it is often assumed that plant invasions will not increase total ecosystem water use, because all available water is evaporated or transpired regardless of vegetation type. However, invasion by exotic species, with high water use rates, may potentially alter ecosystem water balance by reducing water available to native species, which may in turn impact carbon assimilation and productivity of co-occurring species. Here, we document the impact of invasion by an understory exotic woody species (Acacia longifolia) in a semi-arid Mediterranean dune pine forest. To quantify the effects of this understory leguminous tree on the water use and carbon fixation rates of Pinus pinaster we compare an invaded and a non-invaded stand. A. longifolia significantly altered forest structure by increasing plant density and leaf area index in the mid-stratum of the invaded forest. A. longifolia contributed significantly to transpiration in the invaded forest (up to 42%) resulting in a slight increase in stand transpiration in the invaded relative to non-invaded forest. More importantly, both water use and carbon assimilation rates of P. pinaster were significantly reduced in the invaded relative to non-invaded stand. Therefore, this study shows that exotic plant invasions can have significant impacts on hydrological and carbon cycling even in water-limited semi-arid ecosystems through a repartitioning of water resources between the native and the invasive species.     

Neighbourhood association of Cortaderia selloana invasion,soil properties and plant community structure in Mediterranean coastal grasslands

Invasion by alien species is threatening the conservation of native plant communities and the integrity of ecosystems. To gain a better understanding of such impacts, many studies have examined the traits that make alien species successful invaders as well as the factors involved in community invasibility. However, it is necessary to link invader effects on community structure and on ecosystem processes in order to unravel the mechanisms of impact. Cortaderia selloana is a perennial grass native to South America that is invading abandoned agricultural lands close to coastal human settlements in Catalonia (NE Spain). In invaded pastures, we examined the association between C. selloana invasion, soil properties and vegetation structure changes in pastures, comparing the neighbourhood area of influence of C. selloana with areas far from C. selloana. Areas under the influence of C. selloana had lower total soil nitrogen values and higher C/N values than in areas far from C. selloana. Furthermore, the areas affected by C. selloana had lower species, family and life form richness and diversity, and less plant cover. In addition, C. selloana also increased the vertical vegetation structure and changed species composition (only 44% similarity between invaded and non-invaded areas). Our results point out that C. selloana has an effect on its neighbourhood leading to an increase in small-scale variability within invaded fields.     

Impact of Prunus serotina invasion on understory functional diversity in a European temperate forest

We investigated the relationships between the overstory dominance of Prunus serotina, and the functional diversity of the understory plant communities, in a managed European forest. Vegetation, habitat characteristics and disturbance history were surveyed in 32 invaded stands vs. 32 paired uninvaded stands, after a random stratification. Community specialization and functional diversity indices were compared and a RLQ analysis was run to link species traits to environmental variables. The herb layer of invaded stands exhibited significantly more specialist species and a lower trait diversity compared to uninvaded stands, with respect of species richness and vegetation cover. Light arrival to the forest floor and soil properties explained most of the variation in the RLQ analysis, but 20% of the variation strongly correlated with P. serotina dominance and associated disturbances. Traits characterizing shade-tolerant, short-living ruderals and shade-avoiders (vernal geophytes) were significantly associated to invaded stands, while those associated to light-demanding graminoids characterized uninvaded stands. The establishment of functionally close species (seedlings and saplings of native woody species) tended to be lower in invaded stands. We concluded that the invader was becoming the new ecosystem engineer, first by inducing trait convergence and community specialization, thus promoting traits that enable species to capture resources in the new environment it was creating, and second by reducing the grain of local heterogeneities.     

Depth distribution and composition of seed‐banks in alien‐invaded and uninvaded fynbos vegetation

South African fynbos vegetation is threatened on a large scale by invasive woody plants. A major task facing nature conservation managers is to restore invaded areas. The aim of this study was to determine the restoration potential of fynbos following dense invasion by the Australian tree Acacia saligna. The impacts of dense invasion on seed‐bank composition and depth distribution were investigated to determine which fynbos guilds and species have the most persistent seed‐banks. Soil samples were excavated at three different depths for invaded and uninvaded vegetation at two sand plain and mountain fynbos sites. Seed‐banks were determined using the seedling emergence approach. Invasion caused a significant reduction in seed‐bank density and richness at all sites. There was a significant, but smaller, reduction in seed‐bank density and richness with soil depth at three sites. Seed‐bank composition and guild structure changed following invasion. Low persistence of long‐lived obligate seeders in sand plain fynbos seed‐banks indicates that this vegetation type will be difficult to restore from the seed‐bank alone following alien clearance. The dominance of short‐lived species, especially graminoids, forbs and ephemeral geophytes, suggests that regenerating vegetation will develop into a herbland rather than a shrubland. It is recommended that seed collecting and sowing form part of the restoration plan for densely invaded sand plain sites. As seed density remained higher towards the soil surface following invasion, there is no general advantage in applying a mechanical soil disturbance treatment. However, if the shallow soil seed‐bank becomes depleted, for example following a hot fire through dense alien slash, a soil disturbance treatment should be given to exhume the deeper viable seed‐bank and promote recruitment.     

Effects of invasive Typha × glauca on wetland nutrient pools,denitrification, and bacterial communities are influenced by time since invasion

Invasive plants dramatically shift the structure of native wetland communities. However, less is known about how they affect belowground soil properties, and how those effects can vary depending on time since invasion. We hypothesized that invasion of a wetland by a widespread invasive plant (Typha × glauca) would result in changes in soil nutrients, denitrification, and bacterial communities, and that these effects would increase with time since invasion. We tested these hypotheses by sampling Typha-invaded sites of different ages (~40, 20, and 13 years), a Typha-free, native vegetation site, and a restored site (previously invaded ~30–40 years ago) but that had Typha return within 2 years of the restoration. At each site, we measured Typha stem density, plant species richness, soil nutrients, denitrification rates, and the abundance and composition of bacterial denitrifier communities. All Typha-dominated sites had the least plant species richness regardless of time since invasion. Additionally, sites that were invaded the longest exhibited significantly higher concentrations of soil organic matter, nitrate, and ammonium than the native site. In contrast, denitrification was higher in sites invaded more recently. Denitrifier diversity for the nirS gene was also significantly different, with highest nirS diversity in sites invaded the longest. Interestingly, the denitrifier communities within the restored site were most similar to the ones in T. × glauca sites, suggesting a legacy effect. Our study suggests this invader can alter important ecosystem properties, such as native species richness, nutrient pools, and transformations, as well as bacterial community composition depending on time since invasion.     

Influence of vegetation regeneration and agricultural land use on lizard composition,taxonomic and functional diversity between different vegetation types in Caatinga domain,Brazil

Anthropogenic changes in habitats are one of the main threats to biodiversity. Understanding how species diversity and their functions are affected by these changes is crucial to assess environmental impacts. In this work, we aim to understand how lizard composition, taxonomic and functional diversity respond to differences in native vegetation regeneration stages (conserved vegetation and open secondary vegetation) and agricultural land use in different vegetation types (Caatinga sensu stricto, Cerrado sensu stricto and Relictual Humid Forest) in Caatinga domain, Brazil. In more degraded areas (open secondary vegetation and agricultural areas), we found a decline in species evenness, shown by greater dominance of few species. Moreover, we found a lower functional evenness in agricultural areas than in areas of conserved vegetation, which suggests that a smaller portion of functional traits present greater dominance in more anthropized areas. We did not detect any significant differences in species richness, but we did registered differences in species composition in Relictual Humid Forest. Contrary to our expectations, lizard abundance was also greater in more degraded areas, probably as a result of the increased abundance of species benefited by anthropization. In this work, we advance the knowledge of how anthropogenic changes influence lizard diversity and emphasize the importance of analysing different facets of diversity and different habitat environments to understand how anthropization affects patterns in community ecology.