Perspectives in Ecology and Conservation最新文献

The neotropical rattlesnake Crotalus durissus occurs in South America, where it is generally associated to open areas in the dry diagonal of the continent, composed of xeric and savanna biomes. Since the 1950’s, however, the species started to be recorded in rainforest biomes. Land-use change, especially the conversion of forests to pasture, remains a widely believed but still untested hypothesis to explain this range expansion. An equally untested alternative hypothesis is ongoing climate change as a driver of this observed expansion. Here we modeled the current distribution of C. durissus using occurrence records prior to 1950 for model calibration. Model predictions were then evaluated using occurrence records post-1950. The sets of models considered (i) only bioclimatic predictors, (ii) only land-use land-cover predictors, and (iii) a combination of both. Our results indicated that since 1950’s the geographic range of C. durissus is expanding primarily due increase in pasture areas, and, secondarily due to ongoing changes in climate (changes in isothermality and precipitation). This range expansion encompasses the Argentinian Chaco and the arc of deforestation in the Amazon, which were unsuitable before the 1950’s. The ongoing range expansion of the neotropical rattlesnake can become a public health issue, given that it is a venomous snake of medical importance. The expansion of the neotropical rattlesnake range can be controlled through public policies aimed at restraining deforestation (especially in the Amazon and the Gran Chaco) and encouraging reforestation (especially in the Brazilian Atlantic Forest).

Monitoring programs must produce reliable estimates of animal population density to effectively guide management decisions and conservation action. Popular methods used to estimate density rely on visual encounters which are difficult to obtain for many large-bodied mammals in tropical forests. This study uses the Formozov-Malyshev-Pereleshin (FMP) method to produce density estimates for four terrestrial mammals based on track counts collected by Indigenous hunters in the Amazon. The focal species include collared peccary (Peccari tajacu), white-lipped peccary (Tayassu pecari), lowland tapir (Tapirus terrestris), and jaguar (Panthera onca). For each species, track detections were greater than visual detections and were found on more transects with a fewer number of surveys. Density estimates were produced for each focal species in hunted and nonhunted sites. These results were compared against the median of 84 density estimates located in the literature that differentiated between hunted and nonhunted sites in the Amazon. Results demonstrate that the FMP method is a reasonable and cost-efficient method. This method can directly engage Indigenous and other local peoples in research, as opposed to replacing their skills with technologies or professional biologists. Overall, this method complements traditional transect surveys and can improve our understanding and management of wildlife across the tropics.

While telemetry technology has undoubtedly revolutionized ecological research, the impacts to conservation remain in question. Conservation is, after all, an applied discipline with research that is intentionally designed to inform policies and practices that can demonstrably protect biodiversity. Though telemetry is a tool that is commonly used to raise conservation funding, the technology itself cannot generate these policies and practices. Rather, it is the outputs of the analytical processes interrogating the data deriving from telemetry systems that can do so. This distinction is not semantic but rather fundamental to creating more actionable research. We developed conceptual frameworks to delineate the pathways by which telemetry research can be structured to inform conservation policies, practices, and the decisions of funders motivated to support conservation. We demonstrate how the application of these frameworks can reduce the research-implementation gap so as to make biodiversity conservation more effective. While our assessment uses collaring as a case study, our conceptual frameworks are applicable to all research using animal-borne technology seeking to promote the recovery of species of conservation concern.

Plants are essential for our lives because they provide food, medicine, fuel, shelter, and immaterial resources. Understanding patterns of plant uses through large-scale plant use analysis may contribute to the development of a biocultural conservation approach. We conducted a systematic review to assess current knowledge of the ethnoflora of Argentina, as well as to identify taxonomic and geographic patterns of ethnobotanical uses of native plants at the large scale. We analyzed 124 articles reporting the use of 1706 species. We found that the most widely studied region and use category were Chaco and medicine, respectively. The number of useful native species within a family was positively related to the total native species in each family at the country level. In general, species of greatest cultural importance at the country level had a wide distribution. Almost 70% of native plants used in one phytogeographic province were exclusive to it, and species with the highest importance were characteristic elements of its vegetation. We found that southern Argentina has an exclusive ethnoflora that differs from that in a large area of central and northern Argentina. Our review highlights that plants used by people are intimately associated with the local environment, and that species with great cultural importance across phytogeographic provinces are frequent in the landscape. We provide the first analysis of ethnobotanical studies and a database of useful native plants across Argentina. This information highlights strengths and gaps in knowledge of useful native species, which is crucial for conservation, sustainability and human well-being.

Natural hazards — such as storms, floods, and wildfires — can be disastrous phenomena and so can biological invasions, for which impacts are often irrevocable and insidious. Yet, biological invasion awareness remains low compared to natural hazards, and investments to manage invasions remain vastly underfunded and delayed. Here, we quantified biological invasion costs relative to natural hazards, to raise awareness and political leverage. Analysing biological invasions and natural hazards damage cost data over 1980–2019, economic losses from biological invasions were of similar magnitude to natural hazards (e.g., $1,208.0 bn against $1,913.6 bn for storms and $1,139.4 bn for earthquakes). Alarmingly, invasion costs increased faster than natural hazards over time. Similar biological invasions impact magnitudes to natural hazards and faster cost growth rates urge commensurate recognition, coordination and action towards invasions in policies.

The Brazilian Atlantic Forest (BAF) is a global biodiversity hotspot, but its carbon sink capacity, especially in the subtropical portion, is poorly understood. We aimed to evaluate the relationship between biodiversity measures (i.e., taxonomic, functional, and phylogenetic diversity) and net carbon change across subtropical BAF, testing whether there is a win–win situation in the conservation of biodiversity and carbon sink capacity across forests of distinct ages. We obtained the net carbon change from 55 permanent plots, from early successional to old-growth forests, by combining the carbon gains and losses across two censuses. We found that subtropical BAF are on average acting as a carbon sink, but carbon gains and losses varied a lot across plots, especially within late successional/old-growth forests. The carbon sink was consistent across different forest ages, and we did not find a relationship between biodiversity and net carbon change in subtropical BAF. Therefore, conservation programs should aim at both targets in order to maximize the protection of biodiversity and carbon capture across the secondary and old-growth subtropical BAF, especially in a scenario of global changes.

Fires are recurrent in moist tropical savannas, but in recent decades, Neotropical forests have become more affected due to the increased frequency of fires and the extent of burned areas. Currently, there is still limited knowledge on whether and how these disturbance events generate changes in taxonomic and functional diversity that can ultimately lead to the degradation and loss of resilience of tropical forests. To understand the response of Neotropical moist seasonally flooded forests to fire and the impact on taxonomic and functional diversity, we studied forests affected by fires with three degrees of severity and intensity: unburned, severity and intensity burned, and high severity and intensity burned. Regardless of the severity, fire generates a high taxonomic and functional homogenization in the tree and palm community by reducing α and β taxonomic and functional diversity and increasing functional homogenization by filtering species with similar traits. We found that adults with fire avoidance traits, such as deciduousness, and persistence traits, such as resprouting ability, were the ones that better survived the fire. Fire significantly reduced the abundance of evergreen species and those that were dispersed by zoochory. Our findings provide insight into the functional trajectory of Neotropical moist seasonally flooded forests after the fire, indicating that even moderate fire events may lead to a homogenization of these ecosystems and threaten their persistence.

A diverse group of invasive grasses from tropical and subtropical Africa and Asia has spread throughout the Neotropics over the last decades. Despite their strong ecological impact, current and future distribution patterns of these grasses in the region according to climate change is poorly investigated. We chose ten high potential invasive grass species and used ecological niche modeling to project their geographic distribution within the Neotropics under four climate change scenarios (current, SSP1-2.6, SSP3-7.0 and SSP5-8.5 for 2100). Current climatically suitable areas for these invasive species were estimated to account for 51.3% of the Neotropics. Projections of future climatically suitable areas ranged between 47.0% and 57.6%, depending on the climate scenario. Range retractions are projected for Melinis repens and Urochloa decumbens regardless of the SSP scenario, while Arundo donax, Hyparrhenia rufa and Melinis minutiflora are expected to expand their range in all SSP scenarios. Currently, these ten invasive species have suitable areas that greatly overlap in dry regions of the Neotropics, mainly in the savannas of Central Brazil and Central America. However, a reduction in species overlap and a geographical expansion towards wetter regions is expected under the SSP1 and SSP3 scenarios, and towards drier regions under the SSP5 scenario.

Habitat loss has major impacts on biodiversity. Yet, such impacts are not always linear, as there can be threshold values of habitat amount below which species become extirpated from human-modified landscapes (extinction thresholds). This may be particularly the case for species with high habitat spatial requirements, especially in regions with a long land-use history, which have a lower extinction debt. To address these issues, we evaluated the linear and non-linear effects of landscape-scale forest (habitat) loss on primate species richness in regions with relatively new (Amazon) and old (Atlantic Forest) histories of land-use change. We also evaluated the role of mean home range size in regulating species responses to forest loss. Extinction thresholds were higher in the Atlantic Forest (78% remaining forest cover) than in the Amazon (45%), but primate-landscape associations were stronger in the Amazon. Thus, despite its recent land-use history, Amazon primates are more sensitive to habitat loss. As predicted, mean home range size decreased with forest loss in both biomes. Our findings highlight the importance of stopping deforestation in both biomes to maintain habitat amount above these thresholds. Yet, as <30% of the Atlantic Forest cover remains today, promoting restoration initiatives across this biome is paramount.