Perspectives in Ecology and Conservation最新文献

In naturally flowing waters, communities are expected to increase their taxonomic and functional diversity as well as increase the complexity of food web architecture along the longitudinal gradient from headwaters to mouth. However, these theories do not necessarily apply to dammed rivers. We analysed fish communities at 12 locations along the 1700 km stretch of the transnational Uruguay River. We determined species richness, beta-diversity and its components (turnover and nestedness), trophic diversity, and isotopic niches at community level, with particular focus on areas upstream and downstream of the four existing dams. We estimated trophic diversity metrics based on diet analysis, and isotopic niche breadth based on Bayesian isotopic niche models. We detected consistent longitudinal changes, supporting predictions from the River Continuum Concept. However, taxonomic richness, trophic diversity, and isotopic niche decreased abruptly immediately downstream of dams, and the component contributing the most to beta diversity was turnover, with the highest values occurring mainly after the cascade of dams in the upper Uruguay River, fitting expectations from the Serial Discontinuity Concept. The dam-free stretches of the Uruguay River allowed the recovery of ecological diversity as fish richness and trophic and isotopic niche increased. The negative impacts of dams should urgently be considered in the Neotropics, where many large dams are projected.

Colombia has experienced alarming rates of deforestation, posing a threat to forest biodiversity both inside and outside protected areas. Furthermore, a decline in ecological connectivity can potentially disrupt vital ecological processes such as pollination, gene flow, breeding, seed dispersal, among others. To address this issue at a national scale, it is crucial to identify and conserve a comprehensive network of ecological corridors.

In this study, we identified high priority potential ecological corridors linking protected areas in Colombia. We categorized a representative set of 16 threatened mammal species into four ecological profiles. Then, we used Least Cost Path (LCP) analysis to model potential corridors between protected areas as those that minimized resistance for forest species dispersal. To prioritize conservation efforts, we applied the decrease in the Probability of Connectivity index (dPC) to identify corridors with the highest priority.

Our findings emphasize the importance of preserving large forest patches within protected areas for species inhabiting lowland and sub-Andean forests. However, for species residing in Andean and high Andean forests, restoration measures (e.g., increasing forest cover) between protected areas are needed to enhance landscape permeability and facilitate their dispersal, thereby contributing to their conservation.

Our results have practical implications for decision-makers involved in conservation efforts. These findings can aid in identifying conservation priorities for existing protected areas and their surrounding forest habitats in Colombia. Additionally, we provided expert-based resistance values for different forest mammals that can be further used in other large scale connectivity analyses, including other countries where these species inhabit.

The world is calling for ambitious conservation targets for the Amazon, the world's largest hydrographic basin, with an aim to protect 80% of the biome by 2025. With less than two years to reach this target, it is time to bridge scientific, management, and policy divides in understanding and safekeeping the Amazon. A collaborative, concerted effort is required for developing policy strategies toward the integration of riverine biocultural diversity and connectivity to conserve the basin. Building on policy analysis and interviews with diverse stakeholders, this paper identifies key elements that can support the creation of an Amazon basin-wide riverine conservation system’s approach, focusing on public policies and institutional arrangements. The proposed system concentrates on coordinated protection of riverine connectivity and ecosystem services across this transboundary basin. It builds on existing policies, institutions, and governance arrangements to instantly include rivers currently under some form of protection, while providing a platform for investigating other rivers for subsequent inclusion. Fostering transdisciplinary dialogues, addressing power imbalances, and promoting capacity building across scales would facilitate meaningful participation of key stakeholders in the system's governance. Building on local strengths, enforcement would happen at the regional and national levels.

As threats to the marine environment are increasing over time, the United Nations aims to protect 30% of the ocean by 2030 as one of its sustainable development goals. In order to maximize the ecological benefit for the ocean, a coordinated global effort in marine protected area (MPA) planning is necessary. In this context, ecological connectivity between areas should be considered. Connectivity has been integrated in several previous MPA designs however this usually requires exhaustive larval information (which may not be readily available) and/or complex ocean current simulations (which may be arduous at the transnational scale). In this study, we developed a simple passive drift model of larval dispersal as an alternative approach to integrate connectivity in MPA design. By doing so, we determined larvae source and sink areas between the Philippines and Taiwan, and recorded the time it takes for the virtual larvae from the Philippines to reach the sink zones in Taiwan. We used integer linear programming to identify areas best suited for protection in the Philippines, and found that Batanes, Philippines seeds Green Island and Orchid Island in Taiwan. Travel time of the virtual larvae was estimated to range between 7 and 12 days. We also demonstrate that the integrated approach to maximize habitat area and minimize larvae travel time yields promising results for marine conservation. This approach could be instrumental in marine conservation planning, especially in the formulation of a transboundary MPA network.

Preserving tropical forests by avoiding deforestation and forest degradation is essential for maintaining ecosystem services. Brazilian Conservation Units (CUs) and Indigenous Lands (ILs) have effectively prevented deforestation and supported climate regulation. However, these protected areas face increasing threats from forest fires and droughts across the Amazon and Cerrado biomes. This study assesses how disturbances affect climate regulating factors (surface temperature (LST), evapotranspiration (ET), and albedo) in Mato Grosso state, among different land uses (CUs, ILs, and multiple-use areas - MUs). To do so, we analyzed satellite data collected between 2001 and 2020. Results showed that MUs (outside protected areas) had lower ET (∼10%), higher daytime LST (∼1.5 °C), and higher albedo (∼10%) than CUs and ILs in both biomes in 2001. Over the study period, MUs experienced a greater increase in LST (Amazon: ∼1.4 °C; Cerrado: ∼1.1 °C) and albedo (Amazon: ∼6%; Cerrado: ∼3%) compared to protected areas, regardless of the biome. In contrast, ILs and CUs showed smaller mean changes in LST (∼0.2 °C), ET (∼1.3%), and albedo (∼1.3%). These changes were associated with native vegetation loss, forest fires, and water stress. Our results highlight the important role of protected areas in maintaining climate stability, with higher ET, lower LST, and lower albedo than other land uses. However, the long-term preservation of these services within protected areas depends on interventions in surrounding regions, particularly in the Amazon. Protecting and restoring these natural ecosystems is key for safeguarding ecosystem services and climate regulation in tropical regions.

Grassy ecosystems occupy 27% of Brazilian territory and have historically been neglected in conservation efforts and studies about biodiversity. The Campos Sulinos region in Southern Brazil includes open formations in the Pampa and Atlantic Forest domains. This region has the smallest coverage by protected areas in the country and presents high levels of biodiversity and endemism. Besides, this region is under threat due to croplands and exotic tree plantations. Here, we compile a plant population genetics and phylogeography dataset from published studies focusing on species native to the Campos Sulinos to synthesize findings in plant evolution and genetics to better understand the dynamics of genetic diversity in this open ecosystem. We found 58 works on 51 plant species, published from 2005 to 2022. Most studies used only one kind of molecular marker and few loci. The climatic changes during the Pleistocene are likely the main speciation driver either due to the dynamics between grassland and forest or marine transgressions. Overall, high genetic variability and clear structuring of populations were found for the species studied. Regions with high genetic diversity do not coincide with protected areas. We reinforce the necessity of considering high intraspecific genetic diversity and population structure into both conservation and restoration planning, as well as in research within the Campos Sulinos.