scholarly journals Overlooked biodiversity loss in Amazonian smallholder agriculture

2017 ◽  
Author(s):  
Jacob B. Socolar ◽  
Elvis H. Valderrama Sandoval ◽  
David S. Wilcove

ABSTRACTDiversified smallholder agriculture is the main human land-use affecting the western Amazon, home to the world’s richest terrestrial biota, but the scant available data to date have suggested that the biodiversity impacts of this land-use are small. Here, we present comprehensive surveys of birds and trees in primary forest and smallholder agricultural mosaics in northern Peru. These surveys reveal substantial biodiversity losses that have been overlooked by other studies. Avian biodiversity losses arise primarily from biotic homogenization across infrequently surveyed forest habitats (a loss of beta-diversity). Furthermore, tree species richness declines much more steeply than bird richness. Statistical modeling of local habitat features that allow forest-associated species to persist in the smallholder mosaic strongly suggests that our results represent a best-case scenario for Amazonian agricultural biodiversity. We conclude that previous assessments of the biodiversity value of Amazonian smallholder agriculture have been overly optimistic because they are restricted to upland habitat, thereby missing losses in beta diversity; do not evaluate trees; and/or rely on generalizations from less speciose areas of the Neotropics, where habitat specialization amongst species is less prevalent. Smallholder agriculture will likely expand in western Amazonia due to infrastructure development, and it must be seen as a serious threat to the region’s biodiversity.

2021 ◽  
Vol 13 (10) ◽  
pp. 5355
Author(s):  
Vilém Pechanec ◽  
Ondřej Cudlín ◽  
Miloš Zapletal ◽  
Jan Purkyt ◽  
Lenka Štěrbová ◽  
...  

Global and regional biodiversity loss is caused by several drivers including urban development, land use intensification, overexploitation of natural resources, environmental pollution, and climate change. The main aim of our study was to adapt the GLOBIO3 model to the conditions of the Czech Republic (CR) to assess loss of naturalness and biodiversity vulnerability at the habitat level on a detailed scale across the entire CR. An additional aim was to assess the main drivers affecting the biodiversity of habitat types. The GLOBIO3 model was adapted to CZ-GLOBIO by adapting global to local scales and using habitat quality and naturalness data instead of species occurrence data. The total mean species abundance (MSA) index of habitat quality, calculated from the spatial overlay of the four MSA indicators by our new equation, reached the value 0.62. The total value of MSA for natural and near-natural habitats was found to be affected mainly by infrastructure development and fragmentation. Simultaneously, intensity of land use change and atmospheric nitrogen deposition contributed primarily to the low total value of MSA for distant natural habitats. The CZ-GLOBIO model can be an important tool in political decision making to reduce the impact of the main drivers on habitat biodiversity in the CR.


2020 ◽  
Author(s):  
K Varun ◽  
Sutirtha Dutta

AbstractThe Indian Thar desert has lost much of its grasslands over the last few decades, mainly due to land-use change from pastoralism to agriculture. Expanding croplands and intensifying grazing pressures are popularly hypothesized to be major drivers of biodiversity loss in the region. Our study aims to investigate the effects of contemporary land-use change on bird communities of the Western Thar Desert.We surveyed 58 randomly laid line transects in a c2000 sq.km study area, to quantify parameters of bird community structure in three predominant land-use types viz. protected grasslands, rangelands, and non-irrigated croplands. Fieldwork for the study was conducted in the dry season (winter and summer) between December 2018 and April 2019.During winter, overall bird richness and abundance were highest in protected grasslands followed by non-irrigated croplands and rangelands. Protected grasslands also had a higher abundance of diet and habitat specialists. Compared to protected grasslands, density was lower in non-irrigated croplands and rangelands for 35% and 10% of species, respectively. A majority of the negatively affected species were insectivorous grassland specialists.Contrary to the pattern in winter, overall bird richness, abundance, community composition, and guild structure in summer were similar across three land-use types. Only one of the 17 analysed species had lower density in modified land-use types.Overall, protected grassland was the best habitat for birds and was specifically important for specialists, particularly during the winter. Rangelands and fallow croplands sustained most generalists at comparable densities but had severe negative impacts on specialists.Synthesis and application: Our results point out that low-intensity agro-pastoral land-uses can supplement, but not replace, protected areas in conservation of Thar desert’s avifaunal diversity. Our results are consistent with the idea of managing dryland habitats as agro-grassland mosaics with embedded protected areas, in order to reconcile human needs and biodiversity conservation at a landscape scale.


2020 ◽  
Vol 6 (11) ◽  
pp. eaax8574 ◽  
Author(s):  
Matthew C. Hansen ◽  
Lei Wang ◽  
Xiao-Peng Song ◽  
Alexandra Tyukavina ◽  
Svetlana Turubanova ◽  
...  

Tropical forest fragmentation results in habitat and biodiversity loss and increased carbon emissions. Here, we link an increased likelihood of tropical forest loss to decreasing fragment size, particularly in primary forests. The relationship holds for protected areas, albeit with half the rate of loss compared with all fragments. The fact that disturbance increases as primary forest fragment size decreases reflects higher land use pressures and improved access for resource extraction and/or conversion in smaller fragments. Large remaining forest fragments are found in the Amazon and Congo Basins and Insular Southeast Asia, with the majority of large extent/low loss fragments located in the Amazon. Tropical areas without large fragments, including Central America, West Africa, and mainland Southeast Asia, have higher loss within and outside of protected areas. Results illustrate the need for rigorous land use planning, management, and enforcement in maintaining large tropical forest fragments and restoring regions of advanced fragmentation.


2019 ◽  
Vol 5 (2) ◽  
pp. 48-53
Author(s):  
Afrital Rezki, S.Pd., M.Si ◽  
Erna Juita ◽  
Dasrizal Dasrizal ◽  
Arie Zella Putra Ulni

Perkembangan penggunaan tanah bergerak horisontal secara spasial ke arah wilayah yang mudah diusahakan. Penggunaan tanah juga bergerak secara vertikal dalam rangka menaikkan mutunya. Penelitian ini bertujuan untuk menganalisis pola penggunaan lahan, bagaimana manajemen penggunaan lahan di satu wilayah berdasarkan batas Nagari. Metode yang digunakan adalah analsisis spasial dengan interpretasi citra penginderaan jauh, survey lapangan, dan analisis deskriptif. Pertumbuhan pemukiman Nagari Sungai Sariak Kecamatan VII Koto Kabupaten Padang Pariaman mengakibatkan pemanfaatan ruang menjadi tumpang tindih. Diperlukan cara-cara pengelolaan dan managemen penggunaan tanah dalam rangka pembangunan berkelanjutan yang menaikkan taraf hidup masyarakat dan tidak menimbulkan kerugian lingkungan.Terdapat 9 jenis penggunaan lahan yang ada di Nagari Sungai Sariak. Penggunaan lahan tersebut adalah Primary Forest, Secondary Forest, Paddy Field, Settlement, Mixed Plantations, Crop Fields, Water Bodies, Bushes, dan Plantations. Penggunaan lahan yang paling luas di Nagari Sungai Sariak adalah jenis penggunaan lahan Primary Forest, sebesar 48% dari total luas wilayah Nagari Sungai Sariak. Pada tahun 2011 sampai tahun 2016, penggunaan lahan paling luas terjadi pada penggunaan lahan jenis Primary Forest yang kemudian menjadi Mixed Plantations. Land use Changes moved horizontally spatially towards areas that are easily cultivated. The land use also moves vertically in order to increase its quality. This study aims to analyze land use patterns, how land use management in one area is based on Nagari boundaries. The method used is spatial analysis with interpretation of remote sensing images, field surveys, and descriptive analysis. The growth of Nagari Sungai Sariak in Kecamatan VII Koto, Kabupaten Padang Pariaman resulted in overlapping use of space. Management methods are needed and management of land use in the framework of sustainable development that raises the standard of living of the community and does not cause environmental losses. There are 9 types of land use in the Nagari Sungai Sariak. The land uses are Primary Forest, Secondary Forest, Paddy Field, Settlement, Mixed Plantations, Crop Fields, Water Bodies, Bushes, and Plantations. The most extensive land use in Nagari Sungai Sariak is the type of Primary Forest land use, amounting to 48% of the total area of the Nagari Sungai Sariak. From 2011 to 2016, the most extensive land use occurred in Primary Forest land uses which later became Mixed Plantations.


Diversity ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 240
Author(s):  
Alessandro Ferrarini ◽  
Marco Gustin ◽  
Claudio Celada

Biodiversity loss has multiple causes, but habitat degradation through land-use change is the predominant driver. We investigated the effectiveness of the Natura 2000 network in preserving the main wetlands of the two largest islands of the Mediterranean region, whose conservation is critical for many avian species at European and global level, in a 23-year period (1990–2012). In Sardinia, the surroundings of 22 wetlands were affected by an increase in artificial areas (+64 ha/year) and decrease in agricultural (−54 ha/year) and natural (−17 ha/year) ones. In Sicily, the surroundings of 16 wetlands were impacted by an increase in agricultural areas (+50 ha/year) and decrease in natural and semi-natural ones (−62 ha/year). Results show that the Natura 2000 policies were effective in preserving wetlands (no shrinkages detected in both regions), but their surroundings experienced intense processes of degradation and artificialization in all the sub-periods considered (1990–2000, 2000–2006, 2006–2012), whose effects are now threatening waterbirds and wetland integrity. The enlargement of the existing Natura 2000 sites, the creation of new ones and the speedup of the application of the rules of the Habitats and Birds Directives seem necessary to counteract the rapid land-use changes around these important stopover sites.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5596 ◽  
Author(s):  
Qiongdao Zhang ◽  
Dong He ◽  
Hua Wu ◽  
Wei Shi ◽  
Cong Chen

Spiders are a functionally important taxon in forest ecosystems, but the determinants of arboreal spider beta diversity are poorly understood at the local scale. We examined spider assemblages in 324 European beech (Fagus sylvatica) trees of varying sizes across three forest stands in Würzburg (Germany) to disentangle the roles of tree architecture, spatial distance, and dispersal capacity on spider turnover across individual trees. A large proportion of tree pairs (66%) showed higher compositional dissimilarity in spider assemblages than expected by chance, suggesting prominent roles of habitat specialization and/or dispersal limitation. Trees with higher dissimilarity in DBH and canopy volume, and to a lesser extent in foliage cover, supported more dissimilar spider assemblages, suggesting that tree architecture comprised a relevant environmental gradient of sorting spider species. Variation partitioning revealed that 28.4% of the variation in beta diversity was jointly explained by tree architecture, spatial distance (measured by principal coordinates of neighbor matrices) and dispersal capacity (quantified by ballooning propensity). Among these, dispersal capacity accounted for a comparable proportion as spatial distance did (6.8% vs. 5.9%). Beta diversity did not significantly differ between high- and low-vagility groups, but beta diversity in species with high vagility was more strongly determined by spatially structured environmental variation. Altogether, both niche specialization, along the environmental gradient defined by tree architecture, and dispersal limitation are responsible for structuring arboreal spider assemblages. High dispersal capacity of spiders appears to reinforce the role of niche-related processes.


Botany ◽  
2020 ◽  
Vol 98 (9) ◽  
pp. 479-488
Author(s):  
Francisco E. Fontúrbel

Mistletoes are a group of flowering plants that have developed a parasitic lifeform through complex eco-evolutionary processes. Despite being considered a pest, mistletoes represent a keystone forest resource and are involved in complex plant–plant and plant–animal interactions. Their parasitic lifeform and specialized ecological interactions make mistletoes an ideal model with which to understand the effects of anthropogenic disturbances in a changing world. The accelerated growth of the human population has altered all ecosystems on Earth, leading to biodiversity loss. Land-use changes (involving habitat loss, fragmentation, degradation, and transformation processes) can alter the ecological scenario for mistletoe by altering hosts, mutualists, and nutrient cycling. Those changes may have large consequences at the community level, changing the spatial structure of mistletoes, as well as interaction effectiveness, facilitation process, interaction disruption, and novel interactions with invasive species, leading to non-analog communities in the long run. Furthermore, climate change effects operate on a global scale, enhancing the effects of land-use changes. As temperatures increase, many species would alter their distribution and phenology, potentially causing spatial and temporal mismatches. But more critical is the fact that water stress is likely to disrupt key ecological interactions. Thus, mistletoes can provide valuable insights for what we can expect in the future, as a result of human disturbances.


2019 ◽  
Vol 15 (1) ◽  
pp. 70 ◽  
Author(s):  
Warsilan Warsilan

As the capital of the province of East Kalimantan, Samarinda City developments has a rapid progress from year to year. Samarinda City Development has a tendency oriented towards infrastructure development without regard to the existence of the quality of the existing environment. Imbalance of development in Samarinda city is to start decreasing the water catchment area, so its make increasing intensity of flood in the Samarinda City. The purpose of this study was to analyze the impact of changes in land use in the Samarinda city on the ability of the water catchment area. This research method using descriptive approach, the data collection system of primary and secondary. Intensity flood in the Samarinda city  is increasing from year to year, this condition happened as a problem that always occurs during the rainy season. Current development trends, always take an area that should be an infiltration  area for Samarinda City. Culture and inadequate infrastructure conditions such as lack of system of drainage and polder, was another factor causing the high intensity of flood  in Samarinda City. Therefore, the relevant regulations development guidelines for Samarinda  City must consider all aspects of planning, in this case especially the important of a balance of cultivated land and protected areas or zones.Keywords: Changes in land use; intensity of puddles; Samarinda


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Gaëtane Le Provost ◽  
Jan Thiele ◽  
Catrin Westphal ◽  
Caterina Penone ◽  
Eric Allan ◽  
...  

AbstractLand-use intensification is a major driver of biodiversity loss. However, understanding how different components of land use drive biodiversity loss requires the investigation of multiple trophic levels across spatial scales. Using data from 150 agricultural grasslands in central Europe, we assess the influence of multiple components of local- and landscape-level land use on more than 4,000 above- and belowground taxa, spanning 20 trophic groups. Plot-level land-use intensity is strongly and negatively associated with aboveground trophic groups, but positively or not associated with belowground trophic groups. Meanwhile, both above- and belowground trophic groups respond to landscape-level land use, but to different drivers: aboveground diversity of grasslands is promoted by diverse surrounding land-cover, while belowground diversity is positively related to a high permanent forest cover in the surrounding landscape. These results highlight a role of landscape-level land use in shaping belowground communities, and suggest that revised agroecosystem management strategies are needed to conserve whole-ecosystem biodiversity.


2018 ◽  
Vol 10 (8) ◽  
pp. 2764 ◽  
Author(s):  
Abhishek Chaudhary ◽  
Arne Mooers

Efficient forward-looking mitigation measures are needed to halt the global biodiversity decline. These require spatially explicit scenarios of expected changes in multiple indicators of biodiversity under future socio-economic and environmental conditions. Here, we link six future (2050 and 2100) global gridded maps (0.25° × 0.25° resolution) available from the land use harmonization (LUH) database, representing alternative concentration pathways (RCP) and shared socio-economic pathways (SSPs), with the countryside species–area relationship model to project the future land use change driven rates of species extinctions and phylogenetic diversity loss (in million years) for mammals, birds, and amphibians in each of the 804 terrestrial ecoregions and 176 countries and compare them with the current (1900–2015) and past (850–1900) rates of biodiversity loss. Future land-use changes are projected to commit an additional 209–818 endemic species and 1190–4402 million years of evolutionary history to extinction by 2100 depending upon the scenario. These estimates are driven by land use change only and would likely be higher once the direct effects of climate change on species are included. Among the three taxa, highest diversity loss is projected for amphibians. We found that the most aggressive climate mitigation scenario (RCP2.6 SSP-1), representing a world shifting towards a radically more sustainable path, including increasing crop yields, reduced meat production, and reduced tropical deforestation coupled with high trade, projects the lowest land use change driven global biodiversity loss. The results show that hotspots of future biodiversity loss differ depending upon the scenario, taxon, and metric considered. Future extinctions could potentially be reduced if habitat preservation is incorporated into national development plans, especially for biodiverse, low-income countries such as Indonesia, Madagascar, Tanzania, Philippines, and The Democratic Republic of Congo that are otherwise projected to suffer a high number of land use change driven extinctions under all scenarios.


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