scholarly journals BETA DIVERSITY OF BIRDS (Passeriformes, Linnaeus, 1758) IN SOUTHERN AMAZON

2017 ◽  
Vol 18 (0) ◽  
Author(s):  
Welvis Felipe Fernandes Castilheiro ◽  
Manoel do Santos-Filho ◽  
Robson Flores de Oliveira
Keyword(s):  
At Risk ◽  
Beta Diversity ◽  
Biological Diversity ◽  
Environmental Changes ◽  
Selective Logging ◽  
Dry Forest ◽  
Spatial Distance ◽  
Local Conditions ◽  
Flooded Forest ◽  
High Beta

Abstract The importance of estimating the biological diversity and understanding how ecological specialization of species changes with spatially-organized habitats in undeniable. High beta diversity between neighboring places means an elevated number of species living within small distances, which usually are adapted to local conditions and highly vulnerable to anthropogenic actions as deforestation and burning. We investigated beta diversity of birds from the order Passeriformes in Southern Amazon, within landscapes with a large heterogeneous vegetation cover (habitats with flooded forest, dry forest, and marsh palm) through sound, observational, and photographic censuses. We marked 126 points in equidistant transects. A total of 148 species of birds were identified, distributed in 27 families. We found that 97% of the species foraged in flooded forest, 77% in dry forest and 19% in marsh palms, and only 18% foraged in the three habitats. An ordination analyses revealed which species showed the strongest preference to each habitat. The analysis for the Global beta diversity showed that this value is high (Whittaker: 7.7405), and the same pattern was obtained with the measure of pairwise dissimilarity. An influence of spatial distance was clearly observed in the cluster analysis and confirmed with a partial Mantel analysis; however, this was not observed at points that coincided with the transition and substitution of species. The influence of spatial distance in the dissimilarity index (beta diversity) was significant (r: 0.0608, p: 0.0049). The assemblage of species in small local populations with high beta diversity may be at risk if deforestation, selective logging, and poaching continue. In summary, this study provides important information on specific habitats with high beta diversity that may be at risk of destabilization of its populations due to continuing environmental changes imposed by humans.

scholarly journals Local-scale determinants of arboreal spider beta diversity in a temperate forest: roles of tree architecture, spatial distance, and dispersal capacity

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5596 ◽  
Author(s):  
Qiongdao Zhang ◽  
Dong He ◽  
Hua Wu ◽  
Wei Shi ◽  
Cong Chen
Keyword(s):  
Beta Diversity ◽  
Environmental Gradient ◽  
Dispersal Limitation ◽  
Local Scale ◽  
Tree Architecture ◽  
Habitat Specialization ◽  
Spatial Distance ◽  
Species Variation ◽  
Dispersal Capacity ◽  
Canopy Volume

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.

scholarly journals High beta diversity among small islands is due to environmental heterogeneity rather than ecological drift

2018 ◽  
Vol 45 (10) ◽  
pp. 2252-2261 ◽  
Author(s):  
Jinliang Liu ◽  
Mark Vellend ◽  
Zuhua Wang ◽  
Mingjian Yu
Keyword(s):  
Beta Diversity ◽  
Environmental Heterogeneity ◽  
Small Islands ◽  
High Beta ◽  
Ecological Drift

scholarly journals Adaptive sensing scheme using naive Bayes classification for environment monitoring with drone

2018 ◽  
Vol 14 (1) ◽  
pp. 155014771875603 ◽  
Author(s):  
Yao-Hua Ho ◽  
Yu-Te Huang ◽  
Hao-Hua Chu ◽  
Ling-Jyh Chen
Keyword(s):  
Environmental Changes ◽  
Naive Bayes ◽  
Cost Effective ◽  
Parameter Tuning ◽  
Naïve Bayes ◽  
Spatial Distance ◽  
Environmental Sensors ◽  
Adaptive Sensing ◽  
Naive Bayes Classification ◽  
Naïve Bayes Classification

Environmental sensors are important for collecting data to understand environmental changes and analyze environmental issues. In order to effectively monitor environmental changes, high-density sensor deployment and evenly distributed spatial distance between sensors become the requirements and desired properties for such applications. In many applications, sensors are deployed in locations that are difficult and dangerous to reach (e.g. mountaintop or skyscraper roof). To collect data from those sensors, unmanned aerial vehicles are used to act as data mules to overcome the problem of collecting data in challenging environments. In this article, we extend the adaptive return-to-home sensing algorithm with a parameter-tuning algorithm that combines naive Bayes classification and binary search to adapt adaptive return-to-home sensing parameters effectively on the fly. The proposed approach is able to (1) optimize number of sensing attempts, (2) reduce oscillation of the distance for consecutive attempts, and (3) reserve enough power for drone to return-to-home. Our results show that the naive Bayes classification–enhanced adaptive return-to-home sensing scheme is able to avoid oscillation in sensing and guarantees return-to-home feature while behaving more cost-effective in parameter tuning than the other machine learning–based approaches.

The propagule method as a tool to study assemblage dynamics in benthic foraminifera: An example with pH variations

2021 ◽  
Author(s):  
Anna E. Weinmann ◽  
Susan T. Goldstein ◽  
Maria V. Triantaphyllou ◽  
Martin R. Langer
Keyword(s):  
Shallow Water ◽  
Benthic Foraminifera ◽  
Environmental Changes ◽  
Ph Gradients ◽  
Local Conditions ◽  
Recovery Mechanisms ◽  
Decreasing Ph ◽  
Set Up ◽  
Ph Variations ◽  
Insight Into

<p>Benthic foraminifera are important indicators for ecological studies. The assemblage composition of local communities can be used to analyze influences of environmental variables such as temperature, salinity, pH, and others. In recent years, the experimental propagule method has emerged as an effective tool to evaluate the influence of these variables on assemblage dynamics of benthic foraminifera. Propagules (tiny juveniles) of benthic foraminifera are widespread and can survive outside of a species’ natural distribution range. Their ability to become dormant and be re-activated once local conditions become suitable, is an important driver behind the capacity of foraminiferal assemblages to react quickly to environmental changes. In the laboratory, the propagules are first separated from the coarser fractions by sieving and then cultured under different conditions.</p><p>In the present study, we analyzed the effect of ocean pH on the composition of shallow-water assemblages from Corfu Island (Greece). Like other calcifying organisms, assemblages of foraminifera are susceptible to pH variations and have revealed compositional shifts along natural or experimental pH gradients. Our experimental set-up included four pH treatments between 6.5 and 8.5 at constant temperature and salinity (22°C and 38 ppt) for 5 weeks.</p><p>At the conclusion of the cultivation experiment, we found high numbers of grown specimens (825–1564 per replicate) and a high survivability rate throughout all treatments (78–87%). Higher pH (7.8 and 8.5) resulted in assemblages that were dominated by monothalamous and porcelaneous species, whereas lower pH (6.5 and 7.2) lead to a reduction in porcelaneous and an increase in agglutinated species. Several taxa showed significant positive or negative correlations with decreasing pH values.</p><p>Our results are congruent with previous findings that reported compositional shifts from calcareous to agglutinated taxa with decreasing pH (both from culture and field observations). Our study also indicates that the activation of propagules is an important mechanism behind assemblage dynamics in shallow-water foraminifera. As such, it offers an improved insight into potential resilience and recovery mechanisms of foraminiferal assemblages with regard to local or seasonal pH variations as well as ongoing ocean acidification.</p>

Satellite-derived spatiotemporal patterns of environmental changes caused by 2018-2019 wildfires in Arctic-Boreal Russia

2020 ◽  
Author(s):  
Elena Cherepanova ◽  
Valery Bondur ◽  
Viktor Zamshin ◽  
Natalia Feoktistova
Keyword(s):  
Time Series ◽  
Greenhouse Gases ◽  
Forest Fires ◽  
Environmental Changes ◽  
Negative Impact ◽  
Spatiotemporal Patterns ◽  
Atmospheric Composition ◽  
The Arctic ◽  
Satellite Monitoring ◽  
Local Conditions

<p>Forest fires affect environmental changes both directly, changing the type of land cover, causing local and regional air pollution through emissions of greenhouse gases and aerosols, and indirectly through a secondary effect on atmospheric, soil and hydrological processes. The increase in the number and area of uncontrolled wildfires, the degradation of permafrost in high latitude areas leads to a change in the balance of greenhouse gases in the atmosphere, and it results in the negative impact on the Earth’s climatic system.</p><p>This study examined the Arctic-Boreal territories of the Russian Federation, where huge forest fires were observed in 2018-2019. In most of these areas, forest fire detection is carried out only by means of the satellite monitoring without aviation support. The sparsely populated and inaccessible territories are a major factor of the rapid spread of fires over large areas. Most of the forest areas in the region are so-called control zones, where the authorities may decide not to extinguish the fires if they do not threaten settlements and economic facilities, and consider the salvation of forests economically unprofitable. However, there is no reliable data on the environmental consequences of large forest fires in the Arctic-Boreal territories.</p><p>Satellite monitoring of wildfires provides the detection of fire locations, an assessment of their area and burning time. In our study, we used various indices calculated from remote sensing data for the pre-fire and post-fire periods to identify the spatiotemporal patterns of environmental change caused by large wildfires. The Sentinel 5 TROPOMI time series have been analyzed for the short-term and long-term atmospheric composition anomalies detection caused by forest fires in the region. In the process of comparing the methane concentrations time series for the 2018- 2019 fire seasons the constantly high values anomaly zones were found. We believe that these anomalies are resulting from Sentinel-5 CH4 algorithm constrains, which requires additional work on data validation with relation to the local conditions.</p><p>The reported study was funded by RFBR, MOST (China) and DST (India) according to the research project № 19-55-80021</p>

High beta diversity of bacteria in the shallow terrestrial subsurface

2008 ◽  
Vol 10 (10) ◽  
pp. 2537-2549 ◽  
Author(s):  
Jianjun Wang ◽  
Yucheng Wu ◽  
Hongchen Jiang ◽  
Chunhai Li ◽  
Hailiang Dong ◽  
...  
Keyword(s):  
Beta Diversity ◽  
Terrestrial Subsurface ◽  
High Beta

Selective logging and fire as drivers of alien grass invasion in a Bolivian tropical dry forest

2009 ◽  
Vol 258 (7) ◽  
pp. 1643-1649 ◽  
Author(s):  
J.W. Veldman ◽  
B. Mostacedo ◽  
M. Peña-Claros ◽  
F.E. Putz
Keyword(s):  
Tropical Dry Forest ◽  
Selective Logging ◽  
Dry Forest ◽  
Grass Invasion

scholarly journals Promoting long-term forest landscape resilience in the Lake Tahoe basin

2021 ◽  
Author(s):  
Eric S Abelson ◽  
Keith M Reynolds ◽  
Angela M White ◽  
Jonathan W Long ◽  
Charles Maxwell ◽  
...  
Keyword(s):  
At Risk ◽  
Environmental Changes ◽  
Fire Suppression ◽  
Lake Tahoe ◽  
Forest Landscape ◽  
Lake Tahoe Basin ◽  
Management Scenarios ◽  
Environmental Pressures ◽  
Support Tool ◽  
Tahoe Basin

Rapid environmental changes expected in the 21st century challenge the resilience of wildlands around the world. The western portion of the Lake Tahoe basin (LTW) in California is an important ecological and cultural hotspot that is at risk of degradation from current and future environmental pressures. Historical uses, fire suppression, and a changing climate have created forest landscape conditions at risk of drought stress, destructive fire, and loss of habitat diversity. We prospectively modeled forest landscape conditions for a period of 100 years to evaluate the efficacy of five unique management scenarios in achieving desired landscape conditions across the 23,600 hectares of LTW. Management scenarios ranged from no management other than fire suppression to applying treatments consistent with historical fire frequencies and extent (i.e., regular and broadscale biomass reduction). We developed a decision support tool to evaluate environmental and social outcomes within a single framework to provide a transparent set of costs and benefits; results illuminated underlying mechanisms of forest resilience and provided actionable guidance to decision makers. Sixteen attributes were assessed in the model after assigning weights to each, derived through a survey of stakeholder priorities, so that the contribution of each attribute to evaluations of scenario performance was influenced by the combined priorities of stakeholders. We found that removing forest biomass across the landscape, particularly when accomplished using extensive fire-based removal techniques, led to highly favorable conditions for environmental quality and promoting overall landscape resilience. Environmental conditions resulting from extensive fire-based biomass removal also had nominal variation over time, in contrast with strategies that had less extensive and/or used physical removal techniques, namely thinning. Our analysis provided a transparent approach to data assessment, considering the priorities of stakeholders, to provide insights into the complexities of maintaining optimal conditions and managing landscapes to promote ecosystem resilience in a changing world.

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