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1.
PeerJ ; 12: e17647, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38948210

RESUMEN

Background: Anthropogenic activities significantly impact natural ecosystems, leading to alterations in plant and pollinator diversity and abundance. These changes often result in shifts within interacting communities, potentially reshaping the structure of plant-pollinator interaction networks. Given the escalating human footprint on habitats, evaluating the response of these networks to anthropization is critical for devising effective conservation and management strategies. Methods: We conducted a comprehensive review of the plant-pollinator network literature to assess the impact of anthropization on network structure. We assessed network metrics such as nestedness measure based on overlap and decreasing fills (NODF), network specialization (H2'), connectance (C), and modularity (Q) to understand structural changes. Employing a meta-analytical approach, we examined how anthropization activities, such as deforestation, urbanization, habitat fragmentation, agriculture, intentional fires and livestock farming, affect both plant and pollinator richness. Results: We generated a dataset for various metrics of network structure and 36 effect sizes for the meta-analysis, from 38 articles published between 2010 and 2023. Studies assessing the impact of agriculture and fragmentation were well-represented, comprising 68.4% of all studies, with networks involving interacting insects being the most studied taxa. Agriculture and fragmentation reduce nestedness and increase specialization in plant-pollinator networks, while modularity and connectance are mostly not affected. Although our meta-analysis suggests that anthropization decreases richness for both plants and pollinators, there was substantial heterogeneity in this regard among the evaluated studies. The meta-regression analyses helped us determine that the habitat fragment size where the studies were conducted was the primary variable contributing to such heterogeneity. Conclusions: The analysis of human impacts on plant-pollinator networks showed varied effects worldwide. Responses differed among network metrics, signaling nuanced impacts on structure. Activities like agriculture and fragmentation significantly changed ecosystems, reducing species richness in both pollinators and plants, highlighting network vulnerability. Regional differences stressed the need for tailored conservation. Despite insights, more research is crucial for a complete understanding of these ecological relationships.


Asunto(s)
Efectos Antropogénicos , Ecosistema , Polinización , Animales , Agricultura , Biodiversidad , Conservación de los Recursos Naturales , Insectos/fisiología , Plantas
2.
Ann Bot ; 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38722218

RESUMEN

BACKGROUND AND AIMS: The majority of the earth's land area is currently occupied by humans. Measuring how terrestrial plants reproduce in these pervasive environments is essential for understanding their long-term viability and their ability to adapt to changing environments. METHODS: We conducted hierarchical and phylogenetically-independent meta-analyses to assess the overall effects of anthropogenic land-use changes on pollination, and male and female fitness in terrestrial plants. KEY RESULTS: We found negative global effects of land use change (i.e., mainly habitat loss and fragmentation) on pollination and on female and male fitness of terrestrial flowering plants. Negative effects were stronger in plants with self-incompatibility (SI) systems and pollinated by invertebrates, regardless of life form and sexual expression. Pollination and female fitness of pollination generalist and specialist plants were similarly negatively affected by land-use change, whereas male fitness of specialist plants showed no effects. CONCLUSIONS: Our findings indicate that angiosperm populations remaining in fragmented habitats negatively affect pollination, and female and male fitness, which will likely decrease the recruitment, survival, and long-term viability of plant populations remaining in fragmented landscapes. We underline the main current gaps of knowledge for future research agendas and call out not only for a decrease in the current rates of land-use changes across the world but also to embark on active restoration efforts to increase the area and connectivity of remaining natural habitats.

3.
Environ Manage ; 73(5): 913-919, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38424176

RESUMEN

Brazil is among the main contributors to global biodiversity, which, in turn, provides extensive ecosystem services. Agriculture is an activity that benefits greatly from these ecosystem services, but at the same time is degrading aquatic and terrestrial ecosystems and eroding Brazilian biodiversity. This conflict is growing, as emerging unsustainable legislative proposals that will benefit the agricultural sector are likely to accelerate the decline of biodiversity. One such initiative (Bill 1282/2019) would change Brazil's "Forest Code" (Law 12,651/2012) to facilitate construction of irrigation dams in Permanent Preservation Areas, a category that includes strips (with or without vegetation) along the edges of watercourses. Two other similar bills are advancing through committees in the Chamber of Deputies. Here we provide details of these three bills and discuss their consequences for Brazil's biodiversity if they are approved. Expected negative impacts with changes in the legislation include: increased deforestation; siltation; habitat fragmentation; introduction of non-native species; reduction in the availability of aquatic habitats; and changes in biogeochemical process. These proposals jeopardize biodiversity and may compromise the negotiations for an agreement between Mercosur and the European Union.


Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , Brasil , Biodiversidad , Bosques , Agricultura
4.
Braz J Vet Med ; 45: e001023, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37649963

RESUMEN

In this study, we conducted a retrospective survey of 63 giant anteaters (Myrmecophaga tridactyla) using the Federal University of Uberlândia, Minas Gerais State, Brazil as reference site for wild animals. We analyzed the clinical records of 63 animals from January 2016 to February 2020. The information obtained included the location where the anteater was found, the reason for rescue, estimated life stage, gender, weight, general condition of the animal, clinical signs, diagnosis, and destination. Of the 63 animals, 30.15%, (n = 19/63) were found in rural areas, 25.40% (n = 16/63) in urban areas, and 22.22% (n = 14/63) near highways. The main reason for rescue was run-over accidents (n = 18/63, 28.60%). Regarding life stage distribution, 27% (n = 17/63) were cubs, 25.40% (n = 16/63) were adolescent, and 41.26% (n = 26/63) were adults. There was a higher frequency of females (n = 35/63, 56%), and three (9%) of them were pregnant or had cubs. For injury evaluation, three of the 63 giant anteaters were dead on arrival at the rehabilitation site; therefore, we excluded them from this aspect of the study. Of the 60 remaining anteaters, only 13.33% (n = 8/60) of the animals were healthy upon physical examination.The most common condition was traumatic brain injury (n = 32/60 53.33%), followed by fractures (n = 23/60, 38.33%), neonate triad (n = 15/60, 25%), and abrasions (n = 15/60, 25%). The animals presented a high mortality rate (n = 39/60, 65%). The low number of giant anteaters reintroduced to their natural habitat and the high mortality rate of animals sent to rehabilitation centers show that the protection of giant anteaters is important to reduce the number of these animals sent to rehabilitation centers.


Foi realizado um levantamento retrospectivo de 63 tamanduás-bandeira (Myrmecophaga tridactyla) atendidos em um centro de animais selvagens referência na Universidade Federal de Uberlândia, Minas Gerais, Brasil. Foram analisados registros clínicos de 63 animais de janeiro de 2016 a fevereiro de 2020. As informações coletadas foram: local onde foi encontrado, motivo do resgate, idade estimada, sexo, peso, estado geral do animal, sinais clínicos, diagnóstico e destinação. Os animais foram encontrados em áreas rurais (30.15%, n = 19/63), áreas urbanas (25.40%, n = 16/63) e próximo a rodovias (22.22%, n = 14/63). O principal motivo do resgate foram os atropelamentos (28.60%, n = 18/63). A faixa etária foi de 27% (n = 17/63) filhotes, 25.40% (n = 16/63) jovens e 41.26% (n = 26/63) adultos. Encontrou-se maior frequência de fêmeas (56%, n = 35/63), sendo que três (9%) estavam prenhes ou com os filhotes nas costas. Apenas 13.33% (n = 8/60) dos animais apresentavam-se saudáveis ao exame físico. A condição mais comum foi traumatismo cranioencefálico (53,33%, n = 32/60), seguida por fraturas (38.33%, n = 23/60), tríade neonatal (25%, n = 15/60) e escoriações (25%, n = 15/60). Os animais apresentaram alta taxa de mortalidade (65%, n = 39/60). O baixo número de tamanduás reintroduzidos em seu habitat natural e a alta taxa de mortalidade de animais encaminhados para centros de reabilitação, mostram a importância de medidas que os protejam a ponto de reduzir o número de animais encaminhados para esses centros.

5.
Environ Entomol ; 52(2): 279-285, 2023 04 18.
Artículo en Inglés | MEDLINE | ID: mdl-36745143

RESUMEN

Habitat fragmentation is considered an important threat to biodiversity, increasing species exposure to edge effects. The Brazilian Cerrado savanna is considered a biodiversity hotspot and has been converted to small, isolated fragments due to human activities. Ant communities and colony survivorship are known to be affected by edge effects in Cerrado, but to date there is no information on the genetic diversity of ant colonies at the edge of fragmented areas. Here, we investigate if colony genetic diversity and structure of Odontomachus chelifer (Latreille) ants (Hymenoptera: Formicidae) are subject to edge effects in a Cerrado reserve in southeast Brazil. Using microsatellites, we evaluated the number of breeders (queens and males) and the genetic diversity in O. chelifer colonies located in the interior versus edge of a Cerrado fragment. All O. chelifer nests had multiple queens, which presented a low mating frequency. The number of breeders and most estimates of genetic diversity did not differ between colonies at the edge versus interior of the fragment. Genetic structure was not influenced by nest location as well. However, we detected a small and positive increase in the observed heterozygosity in colonies located at fragment edges. High heterozygosity is thought to be particularly important in fast-changing environments, such as edges, providing an advantage for genetic diversity. Further investigation is needed to assess in greater detail how habitat loss affects O. chelifer biology. Our study is a first step toward elucidating edge effects on genetic diversity of ant colonies, a topic still poorly explored in tropical environments.


Asunto(s)
Hormigas , Humanos , Animales , Hormigas/genética , Pradera , Brasil , Ecosistema , Variación Genética
6.
Toxics ; 11(1)2023 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-36668799

RESUMEN

Industrial, agricultural, and urban areas can be sources of pollution and a cause of habitat fragmentation. The Conlara River located in the northeast of San Luis Province suffers different environmental pressures along its course from urban to agro-industrial areas. The present study aims to assess the water quality of the Conlara basin by evaluating how metals and pesticide contamination as well as physicochemical parameters relate to physiological stress in Jenynsia multidentata. Samplings were carried out in four sites characterized by a growing gradient of anthropic impact from the springs to the final sections of the river, starting with tourism passing through urban areas and ending with large agricultural areas (from S1 to S4) during both the dry and wet seasons. A total of 27 parameters were determined (11 physicochemical, 9 heavy metals, and 7 pesticides) in surface waters. Biomarkers (CAT, TBARS, ChE, and MN) showed significant physiological and cytological alterations in J. multidentata depending on the hydrology season. The combination of physicochemical parameters, metals, and pesticide levels allowed typification and differentiation of the sites. Some metal (Cr, Mn, Pb, and Zn) and pesticide (α-BHC, chlorpyrifos, permethrin and cypermethrin, and endosulfan α) levels recorded exceeded the recommended Argentinian legislation values. A principal component analysis (PCA) allowed detection of differences between both seasons and across sites. Furthermore, the differences in distances showed by PCA between the sites were due to differences in the presence of physicochemical parameters, metals, and pesticides correlated with several biomarkers' responses depending on type of environmental stressor. Water quality evaluation along the Conlara River shows deterioration and different types of environmental stressors, identifying zones, and specific sources of pollution. Furthermore, the biomarkers suggest that the native species could be sensitive to anthropogenic environmental pressures.

7.
Ciênc. rural (Online) ; 53(1): 1-5, 2023. tab, graf
Artículo en Inglés | VETINDEX | ID: biblio-1410639

RESUMEN

Mangaba tree is a fruit tree species whose natural populations are fragmented by anthropic actions. For this reason, studies assessing the impact of fragmentation on the diversity and genetic structure of these populations are required in order to establish suitable conservation strategies. In our study, we used data from analyzes through microsatellite markers in computer simulations to estimate the rates of migration and selfing of six mangaba populations. The studied populations are located in the northeastern states of Ceará, Pernambuco and Sergipe. We tested different selfing and migration rates and selected the combination that showed values of observed and expected heterozygosity closest to those previously obtained with microsatellite markers. According to our simulations, selfing and migration were moderate. This may have led to an increase in inbreeding and genetic drift, resulting in low genetic diversity. We recommend expanding the area and reducing disturbance to promote the occurrence of pollinators, which play an important role in increasing genetic diversity.


A mangabeira é uma espécie frutífera cujas populações naturais se encontram fragmentadas por ações antrópicas. Desse modo, são necessários estudos sobre a avaliação do impacto da fragmentação sobre a diversidade e estrutura genética dessas populações para o estabelecimento de estratégias de conservação adequadas. No presente estudo, foram utilizados dados de análises com marcadores microssatélites em simulações computacionais para estimar as taxas de migração e autofecundação de seis populações de mangaba. As populações estudadas estão localizadas nos estados nordestinos do Ceará, Pernambuco e Sergipe. Foram testadas diferentes taxas de autofecundação e migração, e selecionada a combinação que apresentou valores de heterozigosidade observada e esperada mais próximos dos obtidos com marcadores microssatélites. Com base nas simulações, a autofecundação foi de 0,3 e a taxa de migração variou de 0,5 a 0,6, valores que podem ter conduzido ao aumento da endogamia e deriva genética, resultando em baixa diversidade genética. Recomenda-se a expansão da área e a redução de perturbações para promover a ocorrência de polinizadores, que desempenham um papel importante no aumento da diversidade genética.


Asunto(s)
Variación Genética , Apocynaceae
8.
Ciênc. rural (Online) ; 53(1): e20210176, 2023. tab, graf
Artículo en Inglés | LILACS-Express | VETINDEX | ID: biblio-1384549

RESUMEN

ABSTRACT: Mangaba tree is a fruit tree species whose natural populations are fragmented by anthropic actions. For this reason, studies assessing the impact of fragmentation on the diversity and genetic structure of these populations are required in order to establish suitable conservation strategies. In our study, we used data from analyzes through microsatellite markers in computer simulations to estimate the rates of migration and selfing of six mangaba populations. The studied populations are located in the northeastern states of Ceará, Pernambuco and Sergipe. We tested different selfing and migration rates and selected the combination that showed values of observed and expected heterozygosity closest to those previously obtained with microsatellite markers. According to our simulations, selfing and migration were moderate. This may have led to an increase in inbreeding and genetic drift, resulting in low genetic diversity. We recommend expanding the area and reducing disturbance to promote the occurrence of pollinators, which play an important role in increasing genetic diversity.


RESUMO: A mangabeira é uma espécie frutífera cujas populações naturais se encontram fragmentadas por ações antrópicas. Desse modo, são necessários estudos sobre a avaliação do impacto da fragmentação sobre a diversidade e estrutura genética dessas populações para o estabelecimento de estratégias de conservação adequadas. No presente estudo, foram utilizados dados de análises com marcadores microssatélites em simulações computacionais para estimar as taxas de migração e autofecundação de seis populações de mangaba. As populações estudadas estão localizadas nos estados nordestinos do Ceará, Pernambuco e Sergipe. Foram testadas diferentes taxas de autofecundação e migração, e selecionada a combinação que apresentou valores de heterozigosidade observada e esperada mais próximos dos obtidos com marcadores microssatélites. Com base nas simulações, a autofecundação foi de 0,3 e a taxa de migração variou de 0,5 a 0,6, valores que podem ter conduzido ao aumento da endogamia e deriva genética, resultando em baixa diversidade genética. Recomenda-se a expansão da área e a redução de perturbações para promover a ocorrência de polinizadores, que desempenham um papel importante no aumento da diversidade genética.

9.
Rev. bras. parasitol. vet ; 32(3): e005823, 2023. tab, graf
Artículo en Inglés | LILACS-Express | LILACS, VETINDEX | ID: biblio-1515082

RESUMEN

Abstract Knowledge of taxonomy and biodiversity of parasites is fundamental to better understand ecosystem dynamics. The objective of this study was to describe the helminth fauna of two species of marsupials in five fragments of the Atlantic rainforest in the western region of Paraná State, Brazil. In a total of 4050 trap-nights, the animals were captured using Sherman, Tomahawk, and Pitfall traps, euthanized, necropsied, and their organs inspected for helminths. After identification of the parasites, descriptors of infection, such as prevalence, mean abundance, mean intensity, and range of intensity, were calculated. Collectively, six helminth species were observed in 18 animals. The following five species were observed in Marmosa paraguayana: Viannaia hamata (58.8%), Gracilioxyuris agilisis (52.9%), Travassostrongylus sextus (17.6%), Oncicola luehei (5.9%), and Pritchardia boliviensis (5.9%). Whereas the following two species were observed in Monodelphis dimidiata: Trichohelix tuberculata (100%) and Travassostrongylus sextus (100%). This study represents a new locality record for all helminths described herein, and a new host for four helminth species. This is the first report on the helminth fauna of Monodelphis dimidiata, expanding knowledge about marsupials in the Brazilian Atlantic Forest.


Resumo Conhecimentos taxonômicos e da biodiversidade parasitária são fundamentais para uma melhor compreensão da dinâmica do ecossistema. O objetivo do estudo foi descrever a helmintofauna de marsupiais em cinco fragmentos de Mata Atlântica, na região Oeste do Estado do Paraná, Brasil. Em um total de 4.050 armadilhas/noite, os animais foram capturados com as do tipo Sherman, Tomahawk e Pitfall, eutanasiados, necropsiados e seus órgãos inspecionados em busca de helmintos. Após a identificação do parasita, foram calculados os indicadores de infecção (prevalência, abundância média, intensidade média e variação de intensidade). Seis espécies de helmintos foram observadas em dezoito animais; cinco em Marmosa paraguayana: Viannaia hamata (58,8%), Gracilioxyuris agilisis (52,9%), Travassostrongylus sextus (17,6%), Oncicola luehei (5,9%) e Pritchardia boliviensis (5,9%), e duas em Monodelphis dimidiata: Trichohelix tuberculata (100%) e Travassostrongylus sextus (100%). Este estudo representa um novo registro de localidade para todos os helmintos descritos e um novo hospedeiro para quatro deles. Trata-se do primeiro relato da helmintofauna de Monodelphis dimidiata, expandindo-se os conhecimentos sobre marsupiais na mata Atlântica brasileira.

10.
PeerJ ; 10: e14266, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36540793

RESUMEN

Individual dietary specialization is one of the factors that promotes variation in resource use at the individual level. Here we used stable isotope analysis of multiple tissues with different turnover rates to examine the degree of individual specialization in two sub-populations of the predator Cichla temensis inhabiting both fragmented and undammed rivers within the Uatumã River basin of the Amazon. Our results showed that the undammed river provides better conditions to promote individual dietary specialization than the fragmented river. This study contributes to the understanding of how specific life history characteristics of populations of generalist predators are impacted by fragmentation within megadiverse environments such as the Amazon basin.


Asunto(s)
Cíclidos , Ríos , Animales , Isótopos , Conducta Predatoria , Dieta/veterinaria
11.
Rev. biol. trop ; Rev. biol. trop;70(1)dic. 2022.
Artículo en Inglés | LILACS, SaludCR | ID: biblio-1407238

RESUMEN

Abstract Introduction: The effects of habitat transformation have been widely studied and the effects are well-known at different levels of biological organization. However, few studies have focused on responses to this process at the level of multiple taxa in diverse taxonomic and functional groups. Objective: Determine the variations in taxonomic and functional diversity of ants, butterflies, and dung beetles, at a spatial and temporal level in a landscape mosaic of the ecoregion of the Colombian foothills. Methods: We assessed amount of natural habitat and landscape composition in four types of vegetation, during the highest and lowest rain periods. We collected butterflies with hand nets and used baited pitfall traps for dung beetles and ants. Results: Habitat loss positively affected ant and butterfly species richness, and negatively affected dung beetles. The abundance of ants and butterflies had a positive effect on the dominance of species in the transformed vegetation, for dung beetles the abundance was negatively affected by the absence of canopy cover. Habitat loss had no negative effect on functional diversity as there is no difference between natural and transformed vegetation. Conclusions: The amount of habitat, habitat connectivity and different types of vegetation cover were important factors in the maintenance of insect diversity in the modified ecosystems of foothills of the Colombian Orinoquia. The lack of a common spatial and temporal pattern shows that studies of multiple insect taxa should be carried out for biodiversity monitoring and conservation processes.


Resumen Introducción: Los efectos de la transformación del hábitat han sido ampliamente estudiados y son bien conocidos los efectos a diferentes niveles de organización biológica. Sin embargo, pocos estudios se han centrado en las respuestas a este proceso a nivel de múltiples taxones en diversos grupos taxonómicos y funcionales. Objetivo: Determinar las variaciones en la diversidad taxonómica y funcional de hormigas, mariposas y escarabajos coprófagos, a nivel espacial y temporal en un mosaico paisajístico de la ecorregión del piedemonte colombiano. Métodos: Evaluamos la cantidad de hábitat natural y la composición del paisaje en cuatro tipos de vegetación, durante los períodos de mayor y menor lluvia. Recolectamos mariposas con redes de mano y usamos trampas de caída con cebo para escarabajos coprófagos y hormigas. Resultados: La pérdida de hábitat afectó positivamente la riqueza de especies de hormigas y mariposas y afectó negativamente a los escarabajos peloteros. La abundancia de hormigas y mariposas tuvo un efecto positivo sobre la dominancia de especies en la vegetación transformada, para los escarabajos coprófagos la abundancia se vio afectada negativamente por la ausencia de cobertura de dosel. La pérdida de hábitat no tuvo un efecto negativo sobre la diversidad funcional ya que no hay diferencia entre la vegetación natural y la transformada. Conclusiones: La cantidad de hábitat, la conectividad del hábitat y los diferentes tipos de cobertura vegetal fueron factores importantes en el mantenimiento de la diversidad de insectos en los ecosistemas modificados del piedemonte de la Orinoquia colombiana. La falta de un patrón espacial y temporal común muestra que se deben realizar estudios de múltiples taxones de insectos para los procesos de monitoreo y conservación de la biodiversidad.


Asunto(s)
Animales , Hormigas , Escarabajos , Ecosistema , Mariposas Nocturnas , Colombia
12.
Toxics ; 10(7)2022 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-35878251

RESUMEN

The Volcán River watershed in the south Pacific of Costa Rica comprises forests, small urban settlements, cattle fields, and intensive agriculture (mostly pineapple and sugarcane). The ecological integrity and quality of its waters was assessed from 2011-2013 and 2018-2019 by means of physical-chemical parameters (pH, conductivity, temperature, DO, DBO, nitrate, total phosphorus, and pesticide residues) and benthic macroinvertebrate (MI) sampling in eight sites (Volcán, Cañas, and Ángel Rivers, and Peje and Maura streams), resulting in high ecological integrity in all sites except the Peje stream, which is polluted with nitrates and pesticides. Only in this stream was there a marked seasonal variation in the abundance of 16 MI families including Leptohyphidae, Leptophlebiidae, Philopotamidae, Glossossomatidae, and Corydalidae, among others, whose presence was limited exclusively to the dry season (December to April), disappearing from the stream in the rainy season, with corresponding peaks in nitrate (max 20.3 mg/L) and pesticides (mainly herbicides and organophosphate insecticides). The characteristics of the watershed, with large areas of forest and excellent water quality, allow for the re-colonization of organisms into the Peje stream; however, those organisms are incapable of development and growth, providing evidence of a contaminant-driven habitat fragmentation in this stream during the rainy season.

13.
Toxics ; 10(4)2022 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-35448443

RESUMEN

Rivers in the Amazon have among the greatest biodiversity in the world. The Xingu River, one of the tributaries of the Amazon River, has a length of 1640 km, draining 510,000 km2 in one of the most protected regions on the planet. The Middle Xingu region in Brazil has been highly impacted by mining and livestock farming, leading to habitat fragmentation due to altered water quality. Therefore, comparing two rivers (the preserved Xingu River and the impacted Fresco River) and their confluence, the aims of the present study were to (1) assess the land uses in the hydrographic basin; (2) determine the water quality by measurements of turbidity, total solids, and metals (Cd, Cu, Fe, Mn, Pb, Zn, and Hg); (3) compare the zooplankton biodiversity; and (4) to evaluate the avoidance behavior of fish (Astyanax bimaculatus) when exposed to waters from the Xingu and Fresco Rivers. Zooplankton were grouped and counted down to the family level. For the analysis of fish avoidance, a multi-compartment system was used. The forest class predominated at the study locations, accounting for 57.6%, 60.8%, and 63.9% of the total area at P1XR, P2FR, and P3XFR, respectively, although since 1985, at the same points, the forest had been reduced by 31.3%, 25.7%, and 27.9%. The Xingu River presented almost 300% more invertebrate families than the Fresco River, and the fish population preferred its waters (>50%). The inputs from the Fresco River impacted the water quality of the Xingu River, leading to reductions in local invertebrate biodiversity and potential habitats for fish in a typical case of habitat fragmentation due to anthropic factors.

14.
Immunogenetics ; 74(4): 431-441, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35080658

RESUMEN

Habitat fragmentation and infectious diseases threaten wildlife globally, but the interactions of these threats are poorly understood. For instance, while habitat fragmentation can impact genetic diversity at neutral loci, the impacts on disease-relevant loci are less well-studied. We examined the effects of habitat fragmentation in Brazil's Atlantic Forest on amphibian genetic diversity at an immune locus related to antigen presentation and detection (MHC IIB Exon 2). We used a custom high-throughput assay to sequence a fragment of MHC IIB and quantified Batrachochytrium dendrobatidis (Bd) infections in six frog species in two Atlantic Forest regions. Habitat fragmentation was associated with genetic erosion at MHC IIB Exon 2. This erosion was most severe in forest specialists. Significant Bd infections were detected only in one Atlantic Forest region, potentially due to relatively higher elevation. In this region, forest specialists showed an increase in both Bd prevalence and infection loads in fragmented habitats. Reduced population-level MHC IIB diversity was associated with increased Bd infection risk. On the individual level, MHC IIB heterozygotes exhibited a trend toward reduced Bd infection risk, although this was marginally non-significant. Our results suggest that habitat fragmentation increases Bd infection susceptibility in amphibians, mediated at least in part through erosion of immunogenetic diversity. Our findings have implications for management of fragmented populations in the face of emerging infectious diseases.


Asunto(s)
Quitridiomicetos , Micosis , Anfibios , Animales , Anuros/genética , Brasil/epidemiología , Ecosistema , Bosques , Inmunogenética , Micosis/epidemiología , Micosis/genética , Micosis/veterinaria
15.
Ciênc. rural (Online) ; 52(8): e20210303, 2022. ilus, tab
Artículo en Inglés | VETINDEX | ID: biblio-1364730

RESUMEN

Morphometry of fruits and seeds is a useful and important information for phenotyping and genetic characterization of crop plant species and, for conservation of endangered species, as is the case of Butia purpurascens Glassman. In this study, we determined comparatively the morphometric features of fruits and pyrenes between yellow and magenta B. purpurascens morphotypes, located in four different sites (populations). We processed 1380 fruits collected from 69 individuals. We evaluated the length, width and weight of the fruits and pyrenes, the fresh and dry pulp mass, and percentage of pulp moisture. Yellow morph showed larger and heavier fruits than magenta morph. Morphometric differences were also evident among the four populations, suggesting that ecosystems fragmentation can cause deleterious genetic effects in B. purpurascens in long-term.


A morfometria de frutos e sementes é uma informação útil e importante para fenotipagem e caracterização genética de espécies vegetais com potencial econômico e, para a conservação de espécies ameaçadas, como é o caso de Butia purpurascens. Nesse estudo, determinamos comparativamente as características morfométricas de frutos e pirênios entre morfotipos amarelo e magenta de B. purpurascens, localizados em quatro localidades diferentes (populações). Beneficiamos 1380 frutos, coletados em 69 indivíduos. Avaliamos o comprimento, largura e o peso dos frutos e pirênios, a massa fresca e seca da polpa, e a porcentagem de umidade da polpa. O morfotipo amarelo apresentou frutos maiores e mais pesados do que o morfotipo magenta. Diferenças morfométricas também foram notórias entre as quatro populações, sugerindo que a fragmentação de ecossistemas pode causar efeitos genéticos deletérios em B. purpurascens ao longo do tempo.


Asunto(s)
Especies en Peligro de Extinción , Arecaceae/anatomía & histología , Arecaceae/genética , Ecosistema
16.
Mov Ecol ; 9(1): 35, 2021 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-34233767

RESUMEN

BACKGROUND: There is growing evidence that individuals within populations can vary in both habitat use and movement behavior, but it is still not clear how these two relate to each other. The aim of this study was to test if and how individual bats in a Stunira lilium population differ in their movement activity and preferences for landscape features in a correlated manner. METHODS: We collected data on movements of 27 individuals using radio telemetry. We fitted a heterogeneous-space diffusion model to the movement data in order to evaluate signals of movement variation among individuals. RESULTS: S. lilium individuals generally preferred open habitat with Solanum fruits, regularly switched between forest and open areas, and showed high site fidelity. Movement variation among individuals could be summarized in four movement syndromes: (1) average individuals, (2) forest specialists, (3) explorers which prefer Piper, and (4) open area specialists which prefer Solanum and Cecropia. CONCLUSIONS: Individual preferences for landscape features plus food resource and movement activity were correlated, resulting in different movement syndromes. Individual variation in preferences for landscape elements and food resources highlight the importance of incorporating explicitly the interaction between landscape structure and individual heterogeneity in descriptions of animal movement.

17.
PeerJ ; 9: e11673, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34239779

RESUMEN

BACKGROUND: A key challenge for conservation biology in the Neotropics is to understand how deforestation affects biodiversity at various levels of landscape fragmentation. Addressing this challenge requires expanding the coverage of known biodiversity data, which remain to date restricted to a few well-surveyed regions. Here, we assess the sampling coverage and biases in biodiversity data on fruit-feeding butterflies at the Brazilian Atlantic Forest, discussing their effect on our understanding of the relationship between forest fragmentation and biodiversity at a large-scale. We hypothesize that sampling effort is biased towards large and connected fragments, which occur jointly in space at the Atlantic forest. METHODS: We used a comprehensive dataset of Atlantic Forest fruit-feeding butterfly communities to test for sampling biases towards specific geographical areas, climate conditions and landscape configurations. RESULTS: We found a pattern of geographical aggregation of sampling sites, independently of scale, and a strong sampling bias towards large and connected forest fragments, located near cities and roads. Sampling gaps are particularly acute in small and disconnected forest fragments and rare climate conditions. In contrast, currently available data can provide a fair picture of fruit-feeding butterfly communities in large and connected Atlantic Forest remnants. DISCUSSION: Biased data hamper the inference of the functional relationship between deforestation and biodiversity at a large-scale, since they are geographically clustered and have sampling gaps in small and disconnected fragments. These data are useful to inform decision-makers regarding conservation efforts to curb biodiversity loss in the Atlantic Forest. Thus, we suggest to expand sampling effort to small and disconnected forest fragments, which would allow more accurate evaluations of the effects of landscape modification.

18.
Neotrop Entomol ; 50(1): 32-45, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33501630

RESUMEN

As large amounts of natural environments are lost due to urbanization, the role of remnant native vegetation in the preservation of biodiversity has become even more significant. Remnant native forest patches are essential refugia for flora and fauna and are crucial for the maintenance of ecosystem processes in urbanized landscapes. We evaluated the influence of landscape structure on ants and spiders associated with Atlantic Forest remnants in urban landscapes. We sampled 14 forest areas in the Metropolitan Region of Salvador and tested the effect of the landscapes' proportion of forest cover, mean landscape isolation, and mean landscape shape complexity on the taxonomic and functional richness and the community composition of both groups. The species collected were classified into functional groups based on behavioral attributes and environmental preferences. Overall, there were strong adverse effects of forest loss, decreased connectivity, and an increase in edge effects associated with the mean shape complexity of the forest remnants. However, the spiders responded to all three landscape structure characteristics whereas the ants only responded to the landscape mean shape complexity. Our findings indicate that the maintenance of urban forest habitats is essential for the conservation of biodiversity in the Metropolitan Region of Salvador and the preservation of ecological functions performed by species within the forest areas.


Asunto(s)
Hormigas , Biodiversidad , Bosques , Arañas , Urbanización , Animales , Hormigas/clasificación , Brasil , Arañas/clasificación
19.
Pap. avulsos Zool. ; 61: e20216193, 2021. graf, tab
Artículo en Inglés | VETINDEX | ID: vti-32902

RESUMEN

The recent edition of the Red Book of Endangered Brazilian Fauna brings 1,173 threatened species, 86% of them in terrestrial or freshwater environments. For these species, the main threat vector is agricultural activities that affect 519 species (51%). This information brought by the Red Book is examined in-depth and its consistency is discussed in search of an objective view on the impacts of agriculture, its importance, how they affect the different groups of animals, the different biomes of the country, and the different types of habitats continental. Birds, fish, and invertebrates are the groups with the highest number of species threatened by agricultural activity, accounting for more than 70% of the species. Habitat loss is by far the biggest impact caused by the activity, affecting almost 90% of the species. However, there is a difference between the impact of agriculture and livestock. The work seeks to understand why livestock threatens a smaller number of species, although pastures occupy more than twice the area occupied by crops and forestry. The work brings an objective debate on the relationship between agricultural activities and the conservation of wild fauna in Brazil, without falling into the trap of the useless demonization of human activities, highlighting, instead, the need to define and implement strategies for the conservation of biodiversity in the midst the land use matrix itself, complementary to the conservation units, based on the best available information on the vulnerability of fauna to the impacts of this vector.(AU)


Asunto(s)
24444 , Especies en Peligro de Extinción , Biodiversidad , Ecosistema
20.
Artículo en Inglés | LILACS-Express | VETINDEX | ID: biblio-1487507

RESUMEN

Abstract The recent edition of the Red Book of Endangered Brazilian Fauna brings 1,173 threatened species, 86% of them in terrestrial or freshwater environments. For these species, the main threat vector is agricultural activities that affect 519 species (51%). This information brought by the Red Book is examined in-depth and its consistency is discussed in search of an objective view on the impacts of agriculture, its importance, how they affect the different groups of animals, the different biomes of the country, and the different types of habitats continental. Birds, fish, and invertebrates are the groups with the highest number of species threatened by agricultural activity, accounting for more than 70% of the species. Habitat loss is by far the biggest impact caused by the activity, affecting almost 90% of the species. However, there is a difference between the impact of agriculture and livestock. The work seeks to understand why livestock threatens a smaller number of species, although pastures occupy more than twice the area occupied by crops and forestry. The work brings an objective debate on the relationship between agricultural activities and the conservation of wild fauna in Brazil, without falling into the trap of the useless demonization of human activities, highlighting, instead, the need to define and implement strategies for the conservation of biodiversity in the midst the land use matrix itself, complementary to the conservation units, based on the best available information on the vulnerability of fauna to the impacts of this vector.

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