Connectivity of Protected Areas: Effect of Human Pressure and Subnational Contributions in the Ecoregions of Tropical Andean Countries

Phylogenetic diversity and North Andean block conservation

Background

The Northern Andean Block (NAB) harbors high biodiversity; therefore, it is one of the most important areas in the Neotropics. Nevertheless, the settlement of several human populations has triggered the rapid transformation of ecosystems, leading to the extinction or endangerment of many species.

Methods

Because phylogenetic diversity indices quantify the historical distinctness between species, they are adequate tools for evaluating priority conservation areas. We reconstructed 93 phylogenies encompassing 1,252 species and, utilizing their occurrence data sourced from the Global Biodiversity Information Facility, computed the Average Taxonomic Distinctness Index (AvTD) for each grid cell with a spatial resolution of 0.25° within the NAB. The index values for each grid cell were categorized into quantiles, and grid cells displaying values within the upper quantile (Q5) were identified as the most significant in terms of phylogenetic diversity. We also calculated the contribution of endemic species to overall phylogenetic diversity within the NAB, specifically focusing on areas preserved within protected areas.

Results

The NAB Andean region exhibited the highest AvTD, with high AvTD values observed in the middle and southern areas of Cordilleras. Endemic species made a relatively modest contribution to the overall phylogenetic diversity of the NAB, accounting for only 1.2% of the total. Despite their relatively small geographical footprints, protected areas within the NAB have emerged as crucial repositories of biodiversity, encompassing 40% of the total phylogenetic diversity in the region.

Discussion

Although the NAB Andean region has been identified as the most crucial area in terms of AvTD, some regions in the Amazonian Piedemonte and Pacific lowlands have high AvTD levels. Interestingly, some protected areas have been found to harbor higher AvTDs than expected, given their smaller size. Although the delimitation of new PAs and species richness have been the primary factors driving the expansion of PAs, it is also essential to consider the evolutionary information of species to conserve all aspects of biodiversity, or at least cover most of them. Therefore, using phylogenetic diversity measures and the results of this study can contribute to expanding the PA network and improving the connectivity between PAs. This approach will help conserve different aspects of biodiversity and preserve evolutionary relationships between species.

The Delineation and Ecological Connectivity of the Three Parallel Rivers Natural World Heritage Site

Landscape connectivity refers to the degree of continuity between the spatially structured units of a landscape. Ecological connectivity can characterise the degree to which ecological functional areas are connected in terms of function and ecological processes. In this study, the landscape pattern index and ecosystem service values were used to evaluate the ecological functional resistance of each landscape type, taking the Three Parallel Rivers Natural World Heritage Site as an example and the habitat distribution and population size of the Yunnan snub-nosed monkey as a reference. The minimum cost distance model, combined with the barrier impact index (BEI) and ecological connectivity index (ECI), was used to determine the degree of barrier impact on the study area and the ecological connectivity of the core reserve of the heritage site in both 2000 and 2020. The resistances of the different land types and landscape heterogeneity to the ecological function of species migration between the core protected areas of the heritage site were, in descending order, those of the forest, shrubs and grass, water, unused land, cultivated land, and built-up land. In 2020, the study area had a large BEI, with areas such as built-up areas, major roads, the sides of large rivers, and arable land being significant contributors to the blockage of landscape connectivity. The overall landscape connectivity in the study area was generally low, with clear spatial differentiation and a three-column parallel distribution pattern influenced by the topography and landscape. With the adjustment of the core reserve boundaries of the heritage site, the proportion of areas with high connectivity (ECI = 4-5) increased from 11.31% in 2000 to 34.36% in 2020. This increased landscape connectivity was conducive to the migration and reproduction of large terrestrial animals, such as the Yunnan snub-nosed monkey, with increasing numbers of populations and individuals. This study provides theoretical and methodological insights into the delineation and conservation of natural heritage sites and landscape connectivity.

Effectiveness of the Qilian Mountain Nature Reserve of China in Reducing Human Impacts

The management effectiveness of protected areas plays a key role in biodiversity and ecosystem services conservation. We evaluated the effectiveness of Qilian Mountain Nature Reserve (QMNR) in reducing human footprint (HF). Four dominant human activity factors, including population density, land use, road distribution, and night light, were incorporated for HF mapping. Comparisons of the HF value between inside and outside QMNR and its four functional zones were conducted. The results show that both the HF inside and outside of QMNR were increasing, but the difference between them was increasing, indicating partial management effectiveness. The north part of the central reserve has a good effect in reducing human impacts, while the effectiveness was poor at both ends of the reserve. The HF value of the most strictly managed core and buffer zones increased by 10.50 and 6.68%, respectively, for 2010–2020. The QMNR was effective in controlling population density and land use, but ineffective in reducing road construction, mining, and construction of hydropower facilities.

Not only range, but quality: human influence and protected areas within the distribution of mammal species subject to use in the Department of Cundinamarca, Colombia

Mammal conservation in transformed landscapes depends heavily on the role of protected areas, especially for species used by local communities both within and around these areas. We evaluated the level of representation and the magnitude of the influence of humans, via human footprint, across the range of mammals used by local communities in the Department of Cundinamarca, Colombia. We emphasised the differences of the human influence at a department scale and inside Protected Areas (PA). The definition of species used by local communities refers to using a resource for its economic, religious and/or traditional value. Specifically, we addressed whether there is a difference between the magnitude of human influence inside and outside the PAs and if the impact is greater on threatened species, species with greater or lesser representation or according to their use. We found 43 species subject to use in our analysis, with low values of representation when compared with global targets (X̄ ± CD = 10.69% ± 4.99) and with high values of vulnerability, based on the mean value of the Spatial Human Footprint Index (HSFI) (57 ± 2.74). We found a difference of 10.72 points between the average HSFI of the Department and that of the PAs (X̄ ± CD = 10.73 ± 5.98%). This shows that the status of each species’ habitats is less impacted by human activities within PAs and that the conservation areas for all species depend largely on their presence in largely transformed landscapes. Although this seems an expected outcome, the Department of Cundinamarca is one of the less represented on PAs at a national level and has suffered from severe fragmentation; thus, our results highlight the need for improving and expanding the current PA system as most species, especially those subject to use, will depend on their existence for their conservation on the long run.