Perspectives in Ecology and Conservation最新文献

Open biomes such as grasslands, savannas, shrublands are associated with many global biodiversity hotspots, and cover ∼60% of land globally. Yet, extensive and increasing anthropogenic activities threaten their functioning and biodiversity. Here, we argue that, in open biomes, researchers and stakeholders (e.g., policy-makers, practitioners) should more comprehensively acknowledge that more than half of a plant’s biomass is typically located belowground. Not only fine roots but different belowground coarse organs of plants (e.g., thick roots, rhizomes) play key ecosystem functions that have been largely neglected in basic and applied ecology. By more accurately accounting for the distribution of these organs along ecological gradients, their biomass turnover and decomposition rate, we would improve estimates of carbon cycling (core in climate change mitigation policies) as well as ameliorating conservation efforts focused on open biomes worldwide.

Understanding the origin and maintenance of microbial diversity patterns, and the relative importance of local and landscape processes for determining biodiversity is still challenging. We investigated the influence of environmental factors acting at local and landscape scales on several facets of phytoplankton diversity. We conducted standardized surveys in 45 artificial ponds in an agricultural landscape of the Brazilian Cerrado, measuring several local (i.e. limnological variables) and landscape characteristics, and phytoplankton abundance, species richness and functional diversity. Structural Equation Models were used to decompose the multiple relationships that local and landscape factors can have between each other and with phytoplankton diversity. Abundance was determined by pond connectivity and limnological variables (water conductivity, transparency, and ammonia), while species richness was positively related to abundance, but negatively affected by pond age. Further, species richness shows a direct negative relationship with functional evenness, so species-poor communities tended to be overdispersed in the functional space. This complex set of relationships highlights the importance of decomposing environmental, morphometric and spatial factors and considering multiple facets of biodiversity to understand community dynamics. These results provide valuable insights on how artificial pond configuration and management in farmstead strategies can allow maintaining high levels of phytoplankton diversity and other aquatic communities in tropical regions.

Lula’s presidency in Brazil offers great hope for the environment but plans for hydroelectric dams in Amazonia represent an area of concern. The Belo Monte hydroelectric power plant that Lula promoted in his previous administrations and still defends illustrates the contradictions. In 2015 Belo Monte diverted water from the Xingu River through a canal that, since 2019, has left a 130-km river stretch with less than 30% of its natural annual discharge. This has compromised the food security of three Indigenous groups and of traditional non-indigenous river-dwelling people dependent on the river’s fish and turtles. Endemic (and threatened) species and unique ecosystems are now being eliminated. The pending renewal of Belo Monte’s operating license poses a test for the Lula administration’s socioenvironmental commitment. We offer suggestions for improved governance for existing dams like Belo Monte but conclude that no more large dams should be built in Amazonia.

Amphibians and reptiles are important indicators of ecosystem health, yet their populations are declining worldwide due to habitat loss and climate change. Agroecosystems, such as coffee plantations, can provide important habitat for these species. We conducted field surveys in the Sumapaz region of Colombia to identify the habitat structural variables that influence the diversity and abundance of herpetofauna in coffee crops. The canonical correspondence analysis revealed that abundance of leaf litter, leaf litter moisture, shade percentage, plantation area, and plantation age category were the most important variables for determining herpetofauna diversity. Our findings suggest that shaded coffee plantations can sustain herpetofauna diversity, and maintaining a thick layer of leaf litter is critical for establishing complex and structured animal communities. This study proposes a set of sustainable agricultural management principles to promote the existence of amphibians and reptiles in coffee crops. By adopting these practices, it is possible to prevent the decline in the population of amphibians and reptiles due to the expansion of the agricultural frontier, as seen in other coffee-growing regions. The findings of this study contribute to a better understanding of how to balance agricultural production and biodiversity conservation in the context of agroecosystems.

The Brazilian Amazon is one of Earth’s most biodiverse and ecologically important regions. However, research investments for biodiversity in the biome are disproportionately low compared with other regions of Brazil. In 2022, the Amazon received 13% of master's, doctoral and postdoctoral scholarships and hosted 11% of all researchers working in biodiversity postgraduate programs. Amazonian institutions received approximately 10% of all federal budget spent on grants and scholarships and about 23% of all resources destined to support long-term ecological sites. The cities of Manaus and Belém concentrate about 90% of all grants and scholarships available for the entire region. Despite per capita research investment in the Amazon being equal to or better than that available for the more economically developed regions of Brazil, the distribution of resources by area is highly unequal. Increasing research funding for the Amazon region requires differential input by federal agencies and more transnational collaborations and integration between Amazonian programs and international funds.

Theory predicts that susceptibility to disease in ectothermic hosts increases as temperatures depart from host’s thermal optima, because pathogens have functionally broader thermal tolerance ranges and acclimate faster than hosts to shifts in temperature. Hence, hosts adapted to cooler and warmer climates should be at greater risk of infection under abnormally warm and cool conditions, respectively. Batrachochytrium dendrobatidis (Bd) is a chytrid fungus that affects amphibians worldwide. In Brazil's Atlantic Forest, Bd outbreaks have been linked to numerous declines in amphibian populations, particularly in cooler high elevation areas. Thus, we hypothesize that years with abnormally warm temperatures could shift the balance in favor of the pathogen, thereby driving the historical declines. We also hypothesize that warm-adapted amphibians from lowland sites could experience elevated Bd infection risk during abnormally cold years. To test whether thermal mismatch (elevation vs. temperature anomaly) drove shifts in Bd prevalence through time we compiled a comprehensive database spanning 50 years, gathered across an elevational gradient within the Atlantic Forest. In agreement with our predictions, cool-adapted hosts had higher Bd prevalence when temperatures were higher than historical averages. In parallel, Bd prevalence in warm-adapted hosts was higher in colder-than-average years, although frogs from higher elevations exhibited an overall higher risk of disease due to disproportionally high infection prevalence. Our study links the thermal mismatch hypothesis with historical shifts in Bd prevalence in Brazilian frogs, indicating that Bd infections, modulated by climate change, may continue to have a negative impact on Neotropical amphibians.

Environmental DNA (eDNA) metabarcoding is a relatively new technology allowing effective non-invasive analyses and monitoring of biodiversity patterns. Studies on eDNA metabarcoding focus on using sequence data to delimit basic units (i.e., such as Molecular Operational Taxonomic Units – MOTUS – or Amplicon Sequence Variation – ASVs), and after this definition standard analytical approaches from community ecology are applied. However, there is more information inherent to eDNA data and it is now straightforward to use more general approaches in which analyses are based directly on phylogenies or genetic distances between MOTUs or ASVs, rather than in discrete units without any accounting for hierarchical structure, providing a more continuum understanding of biodiversity patterns. Here we briefly review the concepts and methods to incorporate phylogenetic patterns into eDNA metabarcoding analyses, illustrating some of the main issues with eukaryote diversity data along the Araguaia River Basin. Hopefully this perspective stimulates researchers obtaining eDNA metabarcoding data to perform their data under the community phylogenetics framework instead of (or in addition to) the more standard community ecology approach.

Brazil can provide ecosystem services, food, and combat climate change-related vulnerabilities. However, this possibility is obliterated by the increasing deforestation in the Brazilian Legal Amazon derived from illegalities and political incentives to a business-as-usual economic development model that clears land for real estate speculation or extensive agro-livestock. Recently, the state governments of Amazonas, Acre, and Rondônia, supported by agro-livestock-related institutions, proposed a zone for economic development in a region of confluence accounting for 23.37% of these states’ total area. Formerly “Sustainable Development Zone between the States of Amazonas, Acre, and Rondônia” (AMACRO), it was renamed to “Abunã-Madeira Sustainable Development Zone (SDZ)” to meet sustainability criteria; however, environmental impact studies regarding its implementation still lack. By integrating land tenure and official deforestation datasets from 2012 to 2022, we assess whether this region is becoming a notable deforestation hotspot. Results showed growing deforestation trends for all land tenure classes, alarmingly in protected areas, since 2018, when the project was announced. Unlike possible economic gains, deforestation in this region affects essential edaphoclimatic conditions for Brazil’s agro-livestock, worsening environmental and socioeconomic vulnerabilities. Effective territorial planning, environmental impact studies, and law enforcement are urgently needed before establishing the zone to avoid a regional hecatomb.

Agroforestry systems, such as shade coffee plantations, favor the maintenance of woody vegetation, which promotes the presence of pollinators such as hummingbirds. Many shade coffee plantations in Mesoamerica have been abandoned due to the fall in coffee prices and undergone succession processes that increase vegetation complexity. Alternatively, they have been replaced by cattle pastures, which negatively affect hummingbird-plant interactions. Here, we describe the structure of hummingbird-plant interaction networks in three types of land use―late-successional forests, coffee plantations, and cattle pastures―that were derived from a cloud forest in southern Mexico. For one year (2019–2020), we collected bimonthly quantitative data on hummingbird-plant interactions for each type of land use. We found that the network of each land use had a heterogeneous structure, and most species had few linkages. The late forests and coffee plantations had more species, pairs of interactions, and modularity than the cattle pastures. The cattle pasture network had the greatest robustness due to the presence of generalist hummingbirds, which are important for network cohesion in a great disturbance scenario. Furthermore, hummingbird visits were influenced by plant traits, such as foliage height diversity. The study findings suggest that the conversion of natural habitats have implications for the conservation of plant-pollinator interactions and that generalist pollinator species are key to disturbance resiliency.

We identified the 30% most-important forest remnants for conservation in the Atlantic Forest domain in South America based on three bird diversity components: (1) overall species potential distribution, (2) potential distribution of threatened species, and (3) diversity of functional traits. We evaluated the extent of overlap among priority areas using the different approaches and analysed the efficiency of the current Protected Areas network at protecting biodiversity in current and potential future (2040 and 2080) climate scenarios. The overlap among the most important areas is low among the different bird diversity components in all climate scenarios, and few changes were found in priority areas between the current and future scenario. The proportion of species that reached the minimum amount of their distribution areas protected varied from zero to 4% depending on the climate scenario and the species conservation status (threatened or not). Priority areas based on the potential distribution of threatened species were less correlated to areas based on the overall species potential distribution than to functional traits in all climate scenarios, suggesting that there might be considerable differences between species composition and their functionalities. Our analyses point out the main regions where resources should be allocated to conservation of birds in a mega-biodiversity region.