Remnant Native Vegetation Research Articles

Bird-friendly wine country through diversified vineyards.

Vinecology, the integration of ecological and viticultural practices, focuses on the working landscapes of the Mediterranean-climate biomes to make wine-grape production compatible with species conservation. We examined how maintaining remnant native vegetation and surrounding natural areas in and around vineyards, two primary practices of vinecology, may influence bird community richness and composition across a vineyard landscape. We conducted bird surveys over spring and summer (October-January) at 120 sites across a wine-grape growing region in central Chile. The sites were equally divided across vineyards with and without remnant native vegetation, and sites had varying amounts of adjacent natural land cover. We used generalized linear mixed models to examine individual species responses to remnant vegetation in the vineyard at plot scale (within a 50-m radius) in the surrounding natural area (within a 500-1000 m radius). We used the Horn similarity index to explore overall community differences to quantify variations in endemic species, guild detection levels, and species richness between site types. At the plot scale, 9 out of 30 species were positively associated with the proportion of remnant vegetation and 3 species were negatively associated. Six were positively influenced by the proportion of native vegetation in the surrounding landscape and 3 species were negatively associated with proportion of native vegetation. Although overall total detections and richness were significantly greater in continuous mixed Mediterranean forest, 84.9% of these species were also detected in forest remnants within vineyards. Endemics, insectivores, granivores, and omnivores were all more abundant in vineyards with remnant native vegetation than in vineyards without remnant native vegetation. Our results show the value of maintaining and restoring natural vegetation remnants in vineyards as a tool for bird conservation that can be applied in working landscapes of the New World Mediterranean climate regions.

Minimizing the Wallacean shortfall: a small sample reveals new occurrences of ground-dwelling spiders in native Cerrado and exotic pastures in the Midwestern Brazil

Spiders have gained wide acceptance in ecological studies as indicators of environmental quality because they show a strong preference for habitat type and pattern of land use. Knowledge of the spider community in Neotropical landscapes is still incipient. In order to decrease such lack of knowledge, this study provides information on the ground-dwelling spider assemblages in remnants of native Brazilian Cerrado (savanna woodlands) and in exotic pastures (Urochloa spp.; Poaceae). We collected the spiders in two remnants of native vegetation and in four exotic pastures using pitfall traps in Aquidauana, Mato Grosso do Sul, Midwestern Brazil. A total of 141 adults were captured, belonging to 11 families and 22 species of spiders (Arachnida: Araneae). Sixteen species were found in the exotic pastures, 10 in the Brazilian Cerrado, and only four were common to both habitats. We found higher species richness in exotic pastures when compared to Brazilian Cerrado. In addition, four spider species were reported for the first time in the state of Mato Grosso do Sul: Apopyllus silvestrii (Simon, 1905) (Gnaphosidae) sampled in exotic pastures, and Eilica rufithorax (Simon, 1893) (Gnaphosidae), Lycosa inornata Blackwall, 1862 (Lycosidae) and Oxyopes salticus (Hentz, 1845) (Oxyopidae) captured in the remnants of native vegetation. With these results, we minimize the Wallacean shortfall by increasing knowledge on distribution of spiders in remnants of native Cerrado and exotic pastures in the Midwestern Brazil. Moreover, we demonstrate that the ground-dwelling spider assemblage is rich and abundant in exotic pastures, a structurally poor and homogeneous habitat compared to the native vegetation of the Brazilian Cerrado. Then, our findings may aid in understanding the complexity of effects generated by mixed ecosystems on this group of predatory arthropods widely used as bioindicators of environmental and land use changes.

Valley Fever: Environmental Risk Factors and Exposure Pathways Deduced from Field Measurements in California.

Coccidioidomycosis, also known as Valley fever, has been reported among military personnel in Coccidioides-endemic areas of the southwestern United States since World War II. In this study, the prevalence of Coccidioides was confirmed in different soil and dust samples collected near three military bases in California using DNA extraction and Polymerase Chain Reaction (PCR) methods. Analyses of physical and chemical parameters revealed no significant differences between Coccidioides-positive and -negative sites. Soil samples collected in the Mojave Desert (near Twentynine Palms MCAGCC) showed the highest percentage of Coccidioides-positive soil and dust samples. Samples from the San Joaquin Valley (near NAS Lemoore) showed the lowest percentage of positive samples and were restricted to remnants of semi-natural areas between agricultural fields. Our results suggest that soil disturbance around all three military bases investigated poses a potential Coccidioides exposure risk for military personnel and the public. We conclude that once lands have been severely disturbed from their original state, they become less suitable for Coccidioides growth. We propose a conceptual framework for understanding exposure where disturbance of soils that exhibit natural or remnants of native vegetation (Creosote and Salt Bush) generate a high risk of exposure to the pathogen, likely during dry periods. In contrast, Coccidioides-positive sites, when undisturbed, will not pose a high risk of exposure.

Anthropogenic effects on the occurrence of medium‐sized mammals on the Brazilian Pampa biome

AbstractThe Pampa biome within Brazil is one of South America’s most endangered biomes, due to conversion to croplands and use for cattle farming, with very limited coverage by protected areas. We investigated the impacts of (i) human population density, (ii) grassland and (iii) forest cover, (iv) protected areas and (v) mean size of farms on the occurrence patterns of 18 medium‐sized mammal species. We gathered information on the occurrence of these species between 2001 and 2010 from the literature and using unpublished field data from local experts. We obtained 1066 records, varying between 13 and 101 per species. Grassland cover had consistently positive effects on species richness (considering the 18 analyzed species), endangered species (considering 10 species that are endangered or data deficient) and occurrence of five individual species (considering each species separately). Human population density, forest cover and mean size of farms had diverse effects on individual species; however, both forest cover and human population density had positive effects on species richness and endangered species occurrence. For human population density this may result from areas suitable for people being similar to those suitable for many native species. The protected area network of the Pampa biome appeared ineffective at protecting the focal species, with predominantly negative effects on mammal occurrence. This inefficiency is probably related to its minor coverage; only 2.9% of the biome area is under any level of protection and only 0.4% under strict protection. To guarantee the conservation of mammal species in this threatened biome, it is important to protect the last remnants of native vegetation, mainly grasslands, avoiding their conversion into croplands.

Landscape changes decrease genetic diversity in the Pallas’ long-tongued bat

Species with high mobility may have low genetic differentiation among populations due to historical long-distance dispersal, but recent studies show that bat dispersal may be affected by habitat loss and fragmentation. Here, we analyze the effects of landscape contemporary changes and dynamics in paleodistribution during the Quaternary on genetic diversity and differentiation in the Pallas’ long-tongued bat, Glossophaga soricina. We sampled 18 populations in landscapes with different land cover, and used nine microsatellite loci and the sequence of a fragment of the mitochondrial gene cytochrome b (CYB) to obtain genetic data. We performed ecological niche modelling and used general linear mixed models and optimization of multiple resistance surfaces to analyze how landscape structure and climatic suitability affect genetic diversity and differentiation. Our results show that the conversion of natural vegetation, such as forests and savannas, to agriculture, pastures or urban matrices (unsuitable habitats) decreases genetic diversity and increases inbreeding, but has no effect on genetic differentiation among populations, that was likely affected by spatial distance. Our findings point to the importance of maintenance of large areas of natural vegetation remnants to conserve genetic diversity of G. soricina, an important bat pollinator in the Neotropics.

Ranging Behavior of an Arboreal Marsupial in a Plantation Landscape

ABSTRACTForests are becoming increasingly fragmented, primarily because of their conversion to production landscapes. Animals occupying modified landscapes may need to expand their ranges and move longer distances between remnant forest patches to find resources. The establishment of plantations in fragmented landscapes, however, may provide complementary habitat for wildlife and improve connectivity, reducing the amount of movement required. Our objective was to determine the influence of plantations on koala (Phascolarctos cinereus) habitat use and test 2 competing hypotheses on the relationship between plantations and range size. We deployed global positioning system and very high frequency collars on 40 koalas in 2 landscapes (plantation and non‐plantation) in Victoria, Australia. From 68,216 tracking points collected over an 8‐month period, we calculated and compared seasonal home range size and habitat use between landscapes. There was no difference in range size, the size and number of core use areas, or the distance between core use areas between plantation and non‐plantation landscapes. Plantations extend existing koala habitat and facilitate koala movement through a landscape; however, remnant native vegetation is still more frequently used. Consequently, native vegetation (even fragmented, linear roadside vegetation) is of high conservation importance for the persistence of koalas in modified landscapes. © 2020 The Wildlife Society.

Role of grasslands in pest suppressive landscapes: how green are my pastures?

AbstractGrasslands are valuable non‐crop habitats in the world's agricultural regions, providing more than simply forage for grazing domestic and wild animals. They provide refuge and resources that support high levels of arthropod biodiversity, most importantly for natural enemies that provide vital biological control services to the surrounding cropped landscape. Ideally, farmers could manage and manipulate grasslands to boost their biocontrol services, although to achieve this, knowledge of the ecological function of these habitats is essential. Unfortunately, grasslands are often bundled together with other habitat types, such as scrubland and forest, under the label ‘non‐crop habitats’, and little is known about the contribution that these specific habitats make towards landscape pest suppression. While recent research has been investigating the importance of other non‐crop habitat such as native vegetation remnants, the contribution that grassland habitats may make towards landscape pest suppression remains a significant knowledge gap in biocontrol research. Here, the current understanding of grassland habitats as biological control service providers in the world's mixed farming systems is reviewed. Limited research into whether grassland habitats support natural enemies, and thus contribute biological control services to the adjacent surrounding cropped landscape, has returned inconclusive, even conflicting, results. Potential explanations for this inconsistency are explored, including the lack of studies, inadequate estimates of predator impact and the variety of different grassland habitat types studied, including their diversity in composition and management practices. Conclusions drawn from these studies are discussed, and suggestions for management are recommended, including increasing grassland floristic diversity, limiting intensive management practices and implementing weed control. Future research directions are proposed, along with the need to develop a universal grassland classification system for research, management and conservation purposes, using grassland type, floristic diversity and management practices as key axes for classification.

High quality remnant patches in a complex agricultural landscape sustain high spider diversity

Remnant vegetation in agricultural landscapes can play a significant role in supporting farmland biodiversity, especially agriculturally important arthropods such as spiders. Little is known about spider composition in native vegetation remnant patches, or which environmental parameters influence within-patch diversity. Furthermore, data on spider diversity is limited in the Greater Cape Floristic Region (GCFR), a global botanical hotspot of great conservation value. Here we sampled spiders in 12 remnant natural fynbos (sclerophyllous) patches in a fragmented agricultural landscape. Multiple environmental variables were measured at each site (within patch variables and landscape variables), to determine their influence on spider genus richness and assemblage structure. We also did this for ground- and plant-dwelling genera, as well as for their assemblages separately. Overall, natural vegetation remnants supported high spider diversity, even rare and range restricted species. Both patch- and landscape-scale variables influenced spider diversity and assemblage structure. Remnant patch size influenced the assemblage structure of all guilds, and positively influenced overall spider diversity. Similarly, the amount of remnant vegetation in the landscape influenced the assemblage structure of most guilds, as well as positively influencing overall spider diversity, across multiple spatial scales. Additional important variables were rockiness, alien invasive tree species richness and topographic complexity. We show that spider diversity is maintained by remnants of good quality natural vegetation, but also influenced by the complexity of the landscape. Preservation of remnant vegetation patches, regardless of size, throughout the privately-owned farm conservancy landscape maintains spider diversity, and so private land conservation should be promoted.

Pollen dispersal, pollen immigration, mating and genetic diversity in restoration of the southern plains Banksia

AbstractEvaluation of patterns of pollen dispersal, mating systems, population fitness, genetic diversity and differentiation in restoration and remnant plant populations can be useful in determining how well restoration activities have achieved their objectives. We used molecular tools to assess how well restoration objectives have been met for populations of Banksia media in the biodiversity hotspot of south-west Western Australia. We characterized patterns of pollen dispersal within, and pollen immigration into, two restoration populations. We compared mating system parameters, population fitness via seed weight, genetic diversity and genetic differentiation for restoration and associated reference remnant populations. Different patterns of pollen dispersal were revealed for two restoration sites that differed in floral display, spatial aggregation of founders and co-planted species. Proximity to remnant native vegetation was associated with enhanced immigration and more short-range pollen dispersal when other population variables were constant. Greater seed weights at remnant compared to restoration populations were not related to outcrossing rate. Equivalent mating system and genetic diversity parameters and low to moderate levels of genetic differentiation between restoration and remnant populations suggest pollinator services have been restored in genetically diverse restoration populations of local provenance B. media as early as four years from planting.

No Net Loss of Species Diversity After Prescribed Fires in the Brazilian Savanna

Although savannas are fire-adapted ecosystems, prescribing fire for biodiversity conservation remains controversial at least in some regions where savannas occur. Faced with uncertainty, many decision makers and even scientists are still reluctant to prescribe fire for conservation purposes in fire-prone ecosystems, invoking the precautionary principle. Knowledge gaps on the ideal fire regime, such as how and when to burn, and especially the fear of biodiversity losses, are among the main arguments against fire management applied to remnants of native savanna vegetation. To inform this debate, we assessed the impact of prescribed fires on diversity of plants (different growth forms), ants, frogs, lizards, birds, and small mammals, in savannas and grasslands of the Brazilian Cerrado. We assessed the existing species richness, composition, and abundance in areas subjected to long periods of fire suppression and compared to that observed over a short period after prescribed dry-season fires, within each group of plants and animals. Whenever possible, we carried out separate analyses for grassland and savanna. Burning did not significantly reduce species richness of any of the groups analyzed, but had a positive effect on richness of graminoids in grassland. When analyzed at the species level, abundance of most animal groups did not show consistent responses to fire, except for a decrease in some frog populations in grasslands. Forbs, graminoids and subshrubs increased in abundance after fire in grassland areas, though in savanna areas, abundance of forbs and subshrubs tended to decline after fire. Species composition changed little in response to fire as indicated by low levels of dissimilarity between burned and unburned areas. These results confirm the high resilience of Cerrado biota to fire, as expected for savanna ecosystems in general. Besides, we demonstrate here that the risk of biodiversity losses cannot justify the objections to the use of prescribed fire for conservation purposes in the Cerrado.

Estimating the Potential for Conservation and Farming in the Amazon and Cerrado under Four Policy Scenarios

Since 2013, clearing rates have rapidly increased in the Amazon and Cerrado biomes. This acceleration has raised questions about the efficacy of current regional public and private conservation policies that seek to promote agricultural production while conserving remnants of natural vegetation. In this study, we assessed conservation and agricultural outcomes of four potential policy scenarios that represent perfect adherence to private sector, zero-deforestation commitments (i.e., the Amazon soy moratorium—ASM and the Amazon cattle agreements—CA) and to varying levels of implementation of the Brazilian Forest Code (FC). Under a zero-clearing scenario, we find that the extent of croplands as of 2017 within the two biomes (31 MHa) could double without further clearing if agriculture were to expand on all previously cleared land that is suitable for crops. Moreover, at least 47 MHa of land that is already cleared but unsuitable for crops would remain available for pasture. Under scenarios in which only legal clearing under the FC could occur, 51 MHa of additional natural vegetation could be cleared. This includes as many as 1 MHa of nonforest vegetation that could be cleared in the Amazon biome without triggering the ASM and CA monitoring systems. Two-thirds of the total vegetation vulnerable to legal clearing is located within the Cerrado biome, and 19 MHa of this land is suitable for cropland expansion. Legal clearing of all of these areas could reduce biodiversity persistence by 4% within the two biomes, when compared with the zero-clearing scenario, and release up to 9 PgCO2e, with the majority (75%) coming from the Cerrado biome. However, when we considered the potential outcomes of full implementation of the FC, we found that 22% (11 MHa) of the 51 MHa of vegetation subject to legal clearing could be protected through the environmental quotas market, while an additional 1 MHa should be replanted across the two biomes, predominantly in the Amazon biome (73% of the area subject to replanting). Together, quotas and replanting could prevent the release of 2 PgCO2e that would otherwise be emitted if all legal clearing occurred. Based on our results, we conclude that ongoing legal clearing could create additional space for cropland and cattle production beyond the substantial existing stocks of cleared areas but would significantly impair local carbon and biodiversity stocks.

Remnants of native forests support carnivore diversity in the vineyard landscapes of central Chile

AbstractCarnivores play an important role in ecosystem functioning as apex predators. However, most carnivore species are threatened or have been extirpated in human-dominated landscapes. The Mediterranean region of central Chile is a biodiversity hotspot, but expansion of agricultural areas such as vineyards is degrading wildlife habitat. We estimated the species richness and composition of carnivore communities in remnant fragments of sclerophyllous forest-shrubland in the vineyard landscapes of central Chile to evaluate the effects of human disturbance at different spatial scales. We tested two hypotheses: (1) vineyard landscapes with higher levels of human disturbance support a lower diversity of native carnivores in fragments of remnant native vegetation compared to landscapes with larger areas of natural habitat, and (2) habitat specialists and generalists respond differentially to human influence at the habitat vs landscape spatial scale. We used camera traps at 12 sites across the study area and evaluated the impact of human disturbance indicators on the richness and detection frequency of carnivore species. We found that human population density negatively affected carnivore richness and was associated with a lower detection frequency of the Vulnerable guiñaLeopardus guigna. The presence of domestic dogs also had a negative effect on the detection frequency of the guiña and the two native species of foxes, the culpeoLycalopex culpaeusand South American grey foxLycalopex griseus. We conclude that protecting remnants of native forest in vineyard landscapes is crucial for carnivore conservation in central Chile.

Environmental and socioeconomic risk factors associated with visceral and cutaneous leishmaniasis: a systematic review.

We performed a systematic review of the literature published since 1900 about leishmaniasis a neglected vector-borne disease, focused on environmental and social risk factors for visceral (VL) and cutaneous leishmaniasis (CL) to better understand their impact on the incidence of disease. The search terms were "leishmaniasis" AND "risk factors" using Google Scholar, PudMed, and Scielo. We reviewed 177 articles, 95 studies for VL, 75 for CL, and 7 on both forms. We identified 14 categories of risk factors which were divided into three groups: socioeconomic (7), environmental (5), and climate (2) variables. Socioeconomic factors were also associated with disease incidence in vulnerable human populations of arid and tropical developing regions. Environmental and climate factors showed significant associations with the incidence of VL and CL in all the studies that considered them. Proximity to natural vegetation remnants increased disease risk in both the New and Old World while the climate conditions favorable for disease transmission differed among regions. We propose a common conceptual framework for both clinical forms that highlights networks of interaction among risk factors. In both clinical forms, the interplay of these factors played a major role in disease incidence. Although there are similarities in environmental and socioeconomic conditions that mediate the transmission cycle of tropical, arid, and Mediterranean regions, the behavior of vector and reservoirs in each region is different. Special attention should be given to the possibility of vector adaptation to urban environments in developing countries where populations with low socioeconomic status are particularly vulnerable to the disease.

Reproductive success of Trypoxylon (Trypargilum) lactitarse (Hymenoptera: Crabronidae) in a fragmented landscape

ABSTRACT Fragmentation of natural vegetation often implies a reduction in local species richness and abundance. The resources used by bees and wasps for feeding and nesting are distributed quite irregularly in fragmented environments, which influences their foraging behavior, occurrence patterns and reproductive success. The objective of the present work was to determine if the size of native vegetation remnants influences the reproductive success of the solitary wasp species Trypoxylon (Trypargilum) lactitarse Saussure, 1867. Trap-nests were established along the edges of forest fragments of different sizes located in municipalities in the central region of the state of Goiás, Brazil. The nests were used to quantify nesting rate, number of cells with larvae, survival of larvae, proportion of nests attacked by parasitoids, and size of hatched adults. The foundation rate of trap-nests was greater in large fragments, whereas the mean number of cells per nest, parasitoidism rate, larval survival and sex ratios, and size of hatched adults did not differ between large and small fragments. Therefore, it appears that fragment size influences the survival or permanence of adults more so than it does that of the larvae in the studied fragments. There are two possible explanations for the difference in the foundation rate: 1) each female founds, in average, the same number of nests in small and large fragments, but the number of females is lower in the smaller fragments; 2) females have the capacity to provision several nests, but in the larger areas each female founds more nests than in smaller areas. However, it is necessary future studies to differentiate these two hypotheses.

Uso e ocupação do solo e a relação com a fragilidade dos remanescentes florestais na bacia hidrográfica do Rio Cértima/Portugal

Em Portugal, à semelhança do que ocorreu em vastas áreas da Europa Mediterrânea, ocorreram importantes mudanças no uso e ocupação do solo, sobretudo após a segunda metade do século XX. Entre essas alterações destaca-se o abandono agrícola e a florestação de terras antes ocupadas com agricultura, em consequência do êxodo rural e também de políticas públicas adotadas. Neste contexto, o presente trabalho tem como objetivo avaliar o uso e ocupação do solo, os fatores físicos (climáticos, geomorfológicos e pedológicos) e históricos e as fragilidades identificadas nos remanescentes de vegetação autóctone existentes na Bacia do Rio Cértima em Portugal. Para tal, preliminarmente foi executado um diagnóstico geral da área de estudo a partir dos seguintes geoindicadores: Bioma; Clima; Geomorfologia; Geologia; Pedologia; Hipsometria e Declividade. Em seguida, foram calculadas as métricas de paisagem divididas em três categorias: tamanho, borda e forma; e são aplicadas à bacia, em geral, considerando os remanescentes florestais mapeados. Para avaliar a qualidade da vegetação florestal existente realizou-se uma análise em campo em locais selecionados da bacia do rio Cértima, por meio do método Landscape Assessment Protocol (LAP) - Protocolo de Avaliação da Paisagem. Desta forma pode-se observar que a grande parte da cobertura vegetal existente na bacia do rio Cértima é composta por eucaliptos, sendo que foram identificados um total 1220 remanescentes florestais, que ocupam uma área de 8.547,05 ha, equivalente a 15,89% da área da bacia.

Mamíferos terrestres de médio e grande porte em uma área de reserva legal na região centro-oeste de Minas Gerais, Brasil

As Reservas Legais (RL) são áreas localizadas dentro de propriedades rurais e contribuem para manutenção da diversidade de espécies de mamíferos, bem como para a movimentação de espécies entre os fragmentos de vegetação. Este trabalho teve como objetivo quantificar a riqueza e analisar a frequência de ocorrência de mamíferos terrestres de médio e grande porte em uma área de RL de 76,5 ha, no município de Pedra do Indaiá, Minas Gerais, Brasil. O período de amostragem foi de 28 meses, com a utilização dos seguintes métodos de coleta: observação direta, indireta e armadilha fotográfica. Foram registradas 25 espécies, distribuídas em sete ordens e 14 famílias. As ordens mais representativas foram Carnivora, Cingulata e Rodentia, e as menos representativas foram Lagomorpha e Didelphimorphia. Das 25 espécies registradas, seis encontram-se ameaçadas de extinção na lista de espécies da fauna ameaçada no estado de Minas Gerais e, quatro na lista de espécies da fauna ameaçada de extinção no Brasil. A presença de animais em alguma categoria de ameaça sugere a necessidade de manutenção da RL, bem como de remanescentes de vegetação nativa na região a fim de manter a qualidade do habitat necessária à persistência das populações e os serviços ecossistêmicos prestados por ela.

Habitat selection in transformed landscapes and the role of forest remnants and shade coffee in the conservation of resident birds.

Biodiversity conservation in transformed landscapes is becoming increasingly important. However, most assessments of the value of modified habitats rely heavily on species presence and/or abundance, masking ecological processes such as habitat selection and phenomena like ecological traps, which may render species persistence uncertain. High species richness has been documented in tropical agroforestry systems, but comparisons with native habitat remnants generally lack detailed information on species demography and habitat use. We generated a multi-species, multi-measure framework to evaluate the role of habitat selection in the adaptation of species to transformed landscapes, and demonstrate that its use could affect how we value the contribution different land uses make to biodiversity conservation. We analysed 7years of capture-mark-recapture and observation data for twelve species of resident birds present in native forest remnants and shade coffee plantations in a mega-diverse region. We assessed whether species behaved adaptively by evaluating the correlation between measures of habitat preference (occurrence, abundance, fidelity, inter-seasonal variance and age) and performance (body condition, muscle, primary moult, breeding and juveniles) in forest and coffee, and generated hypotheses about their role in species persistence. We documented adaptive habitat selection for seven species, non-ideal selection for four and maladaptive selection for one. While many species showed equal preference and/or equal performance in many traits, in general we found more evidence for birds preferring and/or performing better in forest than coffee, although relationships between our indicators and population adaptation need to be studied further before our proposed framework can be applied to more species and landscapes. While shade coffee can act as a biodiversity-friendly matrix providing complementary or supplementary habitat to a wide range of resident bird species, protecting remnants of native vegetation is still of paramount importance for biodiversity conservation in agricultural landscapes.

The recovery rates of secondary savannas in abandoned pastures are poorly explained by environmental and landscape factors

AbstractQuestionAssessing the natural regeneration potential of degraded savannas is a crucial step in restoration planning, since that assessment will define the need for and costs of active intervention. Predicting natural regeneration, however, depends on the mechanistic understanding of ecosystem resilience. Here, we searched for the factors modulating plant communities spontaneously regenerating in abandoned pastures.LocationTropical savanna (cerrado), Brazil.MethodsOver two years, we quantified changes in the structure, richness and species composition of plant communities in 29 secondary savannas resulting from pasture abandonment. We then investigated the influence of soil and landscape attributes, exotic grass cover and time since pasture abandonment on the recovery rate and species composition of these communities.ResultsThe wide variation among sites was not explained by time since abandonment or distance to the nearest remnant native vegetation. Soil attributes, exotic grasses and native vegetation cover around a pasture explained a small fraction of the variation in the recovery rate. We did not find an isolated factor or a robust set of factors explaining the variation in the recovery rate for all vegetation attributes. Species composition was slightly influenced by exotic grasses, soil penetration resistance, proportion of fine soil particles and time since abandonment. Colonization and resprouting by savanna specialists over the two‐year period were hindered by exotic grasses.ConclusionThe use of predictive models based on soil properties, exotic grasses, landscape attributes or time since abandonment is unfeasible for inferring the recovery rate of savanna structure and richness after pasture abandonment. Case‐by‐case monitoring is required to support decisions on restoration intervention. Other factors, which are almost impossible to obtain, such as land‐use practices and history and the taxonomic or functional composition of pre‐existing vegetation, can potentially influence the recovery rate. Exotic grasses must be controlled to favour colonization and resprouting by savanna specialists.

Movement patterns of an arboreal gecko in fragmented agricultural landscapes reveal matrix avoidance

AbstractAnimal movement through agricultural landscapes is critical for population persistence of species within fragmented native vegetation patches. However, perceived habitat quality and the structural changes between differing land uses within such landscapes can reduce an animal's willingness to move. Understanding when animal movement behaviour varies in response to differing habitat types is necessary for identifying barriers to movement between habitat patches. We quantified the homing success and fine‐scale movement behaviour of a patch‐dependent gecko, Gehyra versicolor, in remnant patches, three different matrix types (crop, pasture and linear plantings), and at varying distances from the edge using fluorescent powder tracking, radio‐telemetry and experimental displacement. We found displaced geckos in pasture environments orientated more strongly and moved farther into farmland after being released and, away from their home ranges in remnant patches. In contrast, we found strong homing ability of displaced animals in plantings and crop matrix types, with animals moving towards remnant patches and away from farmland. Importantly, from the 48 individuals radio‐tracked, none moved into farmland, including pastures, despite 16 individuals approaching edge habitat. Because radio‐tracked geckos did not move into pastures, or any other matrix type, movement further into pasture by displaced animals likely represents limited orientation capacity in pasture rather than preference for pasture. We conclude geckos behaviourally avoided the farmland, irrespective of the presence of complex habitat (e.g. linear plantings). Our findings suggest that, despite efforts to improve farmland quality by planting, farmland is not generally preferred compared to remnant native vegetation. Understanding habitat‐specific movement behaviour is crucial to effectively identifying barriers to animal movement and will improve our efforts to conserve regional populations of patch‐dependent species.

Use of forest remnants and teak (Tectona grandis) plantations by small mammals in Mato Grosso, Brazil

ABSTRACTPlanted forests are replacing extensive areas of degraded pastures. It is extremely relevant for species conservation to understand how the community of small mammals responds to these changes. This study assessed the use of habitats in native remnants surrounded by a teak matrix by small mammals in the Cerrado, in the Pantanal and in the Amazon, in Mato Grosso state, Brazil. We used pitfall, Sherman and Tomahawk traps for sampling. The traps were installed at a distance of 50, 150 and 400 m from the edge of the fragment to the matrix, and the same design was used for the forest fragments. We recorded 22 species with 370 individuals of small mammals captured (13 rodents and nine marsupials), with a total effort of 14,350 conventional traps/night and 4,700 pitfalls/night. In this study, the teak plantation presented a barrier, preventing the dispersion of some species, especially Gracilinanus agilis, Marmosa demerarae, Philander opossum, Neacomys spinosus and Oecomys catherinae. Among the species that used the matrix, 10 were captured mainly up to 150 m from edges, suggesting a decrease in species richness as well as abundance within the matrix compared to remnants, indicating that remnants of native vegetation represent important refuges for small mammal biodiversity.