Perspectives in Ecology and Conservation最新文献

Agricultural intensification is a major driver of biodiversity loss. However, the exact impacts of such loss of key ecosystem service (ES) provisions in agriculture require more scrutiny. We assessed the population loss impacts of a key ES-providing species in an agricultural landscape. We tested the hypothesis that intensive agriculture causes density reduction of frogs known as pest regulators and that negatively affects pest regulation. Different frog densities (high and low) observed in a previous study in low and high agricultural intensification areas were used as treatments in a semi-controlled field experiment. Functional response of the frog species was also studied. Neither high nor low frog density had any significant effect on respective pest populations. Limited feeding rate of the frog species might have contributed to reduced predation pressure on pests. Surprisingly, at low density, frogs significantly reduced the arthropod natural enemies, probably their preferred prey due to the latter’s agility. Unlike in low frog density treatment, increased intraspecific competition at high frog density made them seek out pests as alternative prey to the preferred arthropod pest enemies, whose populations were not affected by frog density. This study for the first time links the population loss of frogs, a potential bio-control agent to ES provision in a multi-trophic system.

Optimizing research efforts for biodiversity monitoring is crucial to conservation projects and actions to increase our ability to inform conservation priorities. However, it requires the financial and human capacity. Euglossini bees have been used in monitoring actions as successful bioindicators. Yet, relationships among variables and stressors are complex and can change over time, environment, and local conditions. Here we investigated the influence of sample area on sampling to maximize the cost-benefit ratio of collection effort and the relationship from Euglossini bees with environmental predictors at a mesoscale (25 km2) in central Amazonia considering PPBio plots structure. We found differences considering the sampling unit scale, including capturing different assemblage species compositions. Most bee species were sampled along the phosphorus gradient. Due to the growth of deforestation in the Amazon Forest, especially in the so-called “Arc of Deforestation”, these bees could provide quick and valuable information about landscape quality. Here we present part of the pieces from a giant puzzle that we still need to complete to provide conservation efforts for this group. Our work highlighted the need to consider soil and nutrient variables other than vegetation and distribute scents traps in larger areas instead of in small plots.

Abiotic determinants of global biogeographical patterns are well known for a range of taxa, particularly plants and vertebrates. However, they are largely undescribed for most arthropods which constitute the bulk of the world biodiversity. Based on recently updated ant databases, we estimate the relative strength of abiotic and topographic determinants of ant species richness at the global scale, and investigate how such determinants vary across zoogeographic realms. We used ant species distribution to estimate ant species richness, the number of sampling points, and estimated species richness per cell of 2° worldwide. We fit simultaneous autoregressive models (SAR) to test the relative importance of six explanatory variables: annual rainfall, rainfall seasonality, mean temperature, actual evapotranspiration, mean altitude, and topographic heterogeneity, on estimated species richness. At the global scale, estimated ant species richness was best explained by annual rainfall and mean temperature. However, while annual rainfall affected positively estimated species richness for most realms, the sign of the mean temperature varied between realms. Furthermore, rainfall seasonality, actual evapotranspiration, mean altitude and topographic heterogeneity affected negatively estimated ant species richness in a number of realms. The variation in ant diversity determinants between realms challenges the generality of the global pattern and demonstrates the importance of regional ecological and historical settings. This provides useful information for conservation planning and helps predict how ants will respond to global and regional climate change.

Conservation actions should account for species natural history and behavior related to differences between sexes. However, most studies have not taken into consideration non-independence of observations from the same individual. We used data from camera-trap surveys undertaken over six consecutive years to investigate habitat use by jaguar (Panthera onca) in varzea seasonally flooded forest. We used hierarchical modeling to assess sex differences in occurrence probability related to environmental factors, while accounting for individual and spatial autocorrelation. Specifically, we tested whether male and female jaguars responded differently to habitat type and anthropogenic influence. Our results do not support previous conclusions related to differences between sexes and indicate that, in the studied area, jaguars are habitat generalists, exploring all environments with similar probability during the low-water season. Human settlements also apparently have little effect on habitat use by jaguars in this area. The lack of avoidance of settlements might be due to the low levels of anthropogenic pressure in the area, which adds support to the effectiveness of sustainable-development reserves. The difference between our results and previous studies may be due to the fact that we took into account individual differences, or may be related to the unique environmental characteristics of the varzea of Mamirauá Sustainable Development Reserve in Central Amazonia.

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.