Impacts of Anthropogenic Disturbance on Vegetation Dynamics: A Case Study of Wadi Hagul, Eastern Desert, Egypt.
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ABSTRACT:
SUBMITTER: Bedair R
PROVIDER: S-EPMC8466335 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Increasing anthropogenic disturbances in Madagascar are exerting constrains on endemic Malagasy lemurs and their habitats, with possible effects on their health and survival. An important component of health is the gut microbiome, which might be disrupted by various stressors associated with environmental change. We have studied the gut microbiome of gray-brown mouse lemurs (Microcebus griseorufus), one of the smallest Malagasy primates and an important model of the convergent evolution of diseases. We sampled two sites: one situated in a national park and the other consisting of a more disturbed site around human settlement. We found that more intense anthropogenic disturbances indeed disrupted the gut microbiome of this lemur species marked by a reduction in bacterial diversity and a shift in microbial community composition. Interestingly, we noted a decrease in beneficial bacteria (i.e., members of the Bacteroidaceae family) together with a slight increase in disease-associated bacteria (i.e., members of the Veillonellaceae family), and alterations in microbial metabolic functions. Because of the crucial services provided by the microbiome to pathogen resistance and host health, such negative alterations in the gut microbiome of mouse lemurs inhabiting anthropogenically disturbed habitats might render them susceptible to diseases and ultimately affecting their survival in the shrinking biodiversity seen in Madagascar. Gut microbiome analyses might thus serve as an early warning signal for pending threats to lemur populations.
| S-EPMC9253676 | biostudies-literature
Project description:BackgroundWadi El Natrun microorganisms have been considered as a new resource for natural products due to its extreme condition of salinity and alkalinity. Therefore, this study was devoted to generate metagemic library from soils collected from such an extreme environment in order to clone a novel cellulase for physique industrial applications.ResultsTotal soil-DNA was successfully extracted, and then digested by different restriction enzymes. Purified fragments ranged ~ 200-6500 bp were ligated and were cloned into plasmid cloning vector (pUC19) by using Escherichia coli DH5α (E. coli) host cells. A constructed metagenomic library composed of 270 clones was screened on carboxymethylcellulose (CMC) agar plate where the active clones had been characterized by the formation of the yellowish halo zone. Thereafter, clone 1 was selected as the most active as being based on cellulase activity quantification (19 μ/ml). Plasmid related to clone 1 encoded cellSNSY gene of approximately 1.5 kb was subjected to molecular characterization; the obtained partial sequence of 861 bps encoded 287 amino acids showing 76% similarity to the endoglucanase gene of Bacillus amyloliquefaciens. The recombinant cellSNSY was expressed under lacz promoter at 1 mM of isopropyl β-d-1-thiogalactopyranoside (IPTG), giving 21 μ/ml cellulase after ~ 27 h. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and an activity staining of the recombinant cellSNSY which revealed an active band with a molecular mass ~ 59 kDa appeared in the induced sample. The maximum enzyme activity of crude cellSNSY was observed at 45 °C and for a pH of 8.5. Interestingly, the enzyme activity was slightly inhibited by ethylenediamine tetraacetic acid (EDTA) and methanol. It showed high resistance to the tested heavy metals and the surfactant which ordered Zn> (SDS,Fe)>Mn>Cu.ConclusionsThis study established an easy and a skillful way to clone/express a new found cellulase gene(s) under lacZ promoter. The isolated recombinant cellSNSY showed 76% similarity to endoglucanase gene, and the enzyme showed tolerance to the mostly tested agents including heavy metals, surfactant, solvents, and EDTA. Additionally, the studied recombinant showed a high stability up to 55 °C and for alkaline pH 8.5. These features make it an ample and viable for many applications.
| S-EPMC8825895 | biostudies-literature
Project description:Upland moorlands are important landscapes, but many are considered degraded as a result of human activities. Consequently, their protection and restoration are of substantial concern. In Europe, restoration activities are often aimed at reversing the effects of 19th and 20th century "agricultural improvements," which often involved major drainage schemes. However, the ecological effects and long-term ecological context of "agricultural improvement" are not yet fully understood. To develop this understanding, we analyze paleoecological data (pollen, coprophilous fungal spores, microcharcoal) from five upland peatland sites using a range of analytical approaches: cluster analysis, principal component analysis, rate-of-change analysis, and regression analyses incorporating documentary historical data. The sites are located on Exmoor (South West England, UK), a landscape that typifies historic upland degradation. We demonstrate that in this landscape, 19th century drainage is associated with declines in Sphagnum and non-arboreal taxon richness; over longer timescales burning is associated with enhanced graminoid monocot abundance and grazing with lower taxon richness. We also show that rate-of-change in moorland vegetation communities during the 19th century is not distinctive in a long-term context: change has been a constant in this landscape, rather than an exception during the 19th century. Our findings indicate that the aims of "restoration" interventions intended to increase Sphagnum abundances, increase taxon richness and reduce graminoid dominance are consistent with the long-term dynamics of peatland systems, such as those on Exmoor. "Restoration" deemed successful in these terms may or may not resemble pre-drainage conditions, which were themselves a function of millennia of successive moorland management regimes.
| S-EPMC9994610 | biostudies-literature
Project description:A primary impediment to understanding how species diversity and anthropogenic disturbance are related is that both diversity and disturbance can depend on the scales at which they are sampled. While the scale dependence of diversity estimation has received substantial attention, the scale dependence of disturbance estimation has been essentially overlooked. Here, we break from conventional examination of the diversity-disturbance relationship by holding the area over which species richness is estimated constant and instead manipulating the area over which human disturbance is measured. In the boreal forest ecoregion of Alberta, Canada, we test the dependence of species richness on disturbance scale, the scale-dependence of the intermediate disturbance hypothesis, and the consistency of these patterns in native versus exotic species and among human disturbance types. We related field observed species richness in 1 ha surveys of 372 boreal vascular plant communities to remotely sensed measures of human disturbance extent at two survey scales: local (1 ha) and landscape (18 km2). Supporting the intermediate disturbance hypothesis, species richness-disturbance relationships were quadratic at both local and landscape scales of disturbance measurement. This suggests the shape of richness-disturbance relationships is independent of the scale at which disturbance is assessed, despite that local diversity is influenced by disturbance at different scales by different mechanisms, such as direct removal of individuals (local) or indirect alteration of propagule supply (landscape). By contrast, predictions of species richness did depend on scale of disturbance measurement: with high local disturbance richness was double that under high landscape disturbance.
| S-EPMC4423832 | biostudies-literature
Project description:Law enforcement and massive media awareness, limiting the anthropogenic disturbance, is the way to go for implementing successful desert native vegetation recovery plans. A lesson learned on the resiliency of desert ecosystems throughout studying the native vegetation coverage in the Wadi Al-Batin desert ecosystem during the COVID-19 pandemic. Wadi Al-Batin tri-state desert (89,315 km2) covers the South-western part of Iraq, State of Kuwait, and the North-eastern part of Saudi Arabia. In this study, the spatiotemporal changes in vegetation coverage was detected, by using Sentinel-2A imageries, during the period from 2017 to 2020. For better understanding the impact of associated law enforcement and media practices during COVID-19 pandemic, native vegetation coverage of years with relevant rainfall records were compared. The results revealed that despite receiving the least amount of rain of the three years (≤93 mm), the COVID-19 year (2020) had the highest native vegetation coverage at 28.5% compared with 6% in 2017, and 2% in 2018. These results prove that the main drivers of desert vegetation deterioration are anthropogenic activities, such as quarrying, overgrazing, distractive camping, and off-road vehicle movements. Moreover, the estimated 63% vegetation coverage in Wadi Al-Batin desert in 2019 assures the significant role of precipitation in desert vegetation recovery. This bulk increase in vegetation coverage detected during COVID-19 pandemic shows that the desert vegetation adapts to harsh environments (low rainfall) and rapidly recovers once the source of the disturbance was removed by enforcing the environmental rules. Thus, the protection of natural resources and ecosystems can be achieved through the synergy between governments and civil communities, including intensive awareness of environmental impacts via media, enforcing environmental regulations, and promoting regional collaboration.
| S-EPMC9764450 | biostudies-literature
Project description:Anthropogenic-based disturbances may alter peatland soil-plant causal associations and their ability to sequester carbon. Likewise, it is unclear how the vegetation attributes are linked with different soil C decomposition-based pools (i.e., live moss, debris, and poorly- to highly-decomposed peat) under grassing and harvesting conditions. Therefore, we aimed to assess the relationships between aboveground vegetation attributes and belowground C pools in a Northern Patagonian peatland of Sphagnum magellanicum with disturbed and undisturbed areas. We used ordination to depict the main C pool and floristic gradients and structural equation modeling (SEM) to explore the direct and indirect relationships among these variables. In addition, we evaluated whether attributes derived from plant functional types (PFTs) are better suited to predict soil C pools than attributes derived from species gradients. We found that the floristic composition of the peatland can be classified into three categories that follow the C pool gradient. These categories correspond to (1) woody species, such as Baccharis patagonica, (2) water-logged species like Juncus procerus, and (3) grasslands. We depicted that these classes are reliable indicators of soil C decomposition stages. However, the relationships change between management. We found a clear statistical trend showing a decrease of live moss, debris, and poorly-decomposed C pools in the disturbed area. We also depicted that plant diversity, plant height, and PFT composition were reliable indicators of C decomposition only under undisturbed conditions, while the species-based attributes consistently yielded better overall results predicting soil C pools than PFT-based attributes. Our results imply that managed peatlands of Northern Patagonia with active grassing and harvesting activities, even if small-scaled, will significantly alter their future C sequestration capacities by decreasing their live and poorly-decomposed components. Finally, aboveground vegetation attributes cannot be used as proxies of soil C decomposition in disturbed peatlands as they no longer relate to decomposition stages.
| S-EPMC8935636 | biostudies-literature
Project description:Severe dust events have occurred frequently in arid regions, which greatly impacted air quality, climate, and public health. The Middle East is one of the areas in the world impacted by intense dust storms. We investigated the characteristics of airborne dust levels in five Middle Eastern countries (Kuwait, Iraq, Iran, Saudi Arabia, and Syria) from 2001 to 2017. Surface level dust concentrations were determined using the Modern-Era Retrospective analysis for Research and Applications version 2. Kuwait was selected as an example to assess sources and other factors influencing dust levels in arid regions. We performed backward trajectory analysis to identify the dust transport pathways. We quantitatively assessed the impacts of meteorological parameters along with the Normalized Difference Vegetation Index (NDVI). Dust levels in Kuwait were higher than the other four countries, and had a distinct seasonal pattern, with the highest in summer and the lowest in winter. Our results showed that dust levels in Kuwait in January were influenced largely by local emissions, whereas in June they were affected more by emissions attributable to long-distance transport. There were significant positive associations between wind speed in the five countries, particularly Iraq, with dust levels in Kuwait, indicating the impact of nearby desert areas. Significant negative associations were observed between NDVI in Kuwait, Iraq, and Saudi Arabia with dust levels in Kuwait. Our result highlights that climatic variations and vegetation conditions are associated with changes in dust levels in arid regions.
| S-EPMC7085415 | biostudies-literature
Project description:BACKGROUND:Biological invasions provide a window on the process of community assembly. In particular, tracking natural enemy recruitment to invading hosts can reveal the relative roles of co-evolution (including local adaptation) and ecological sorting. We use molecular data to examine colonisation of northern Europe by the parasitoid Megastigmus stigmatizans following invasions of its herbivorous oak gallwasp hosts from the Balkans. Local host adaptation predicts that invading gallwasp populations will have been tracked primarily by sympatric Balkan populations of M. stigmatizans (Host Pursuit Hypothesis). Alternatively, ecological sorting allows parasitoid recruitment from geographically distinct populations with no recent experience of the invading hosts (Host Shift Hypothesis). Finally, we test for long-term persistence of parasitoids introduced via human trade of their hosts' galls (Introduction Hypothesis). RESULTS:Polymorphism diagnostic of different southern refugial regions was present in both mitochondrial and nuclear microsatellite markers, allowing us to identify the origins of northern European invaded range M. stigmatizans populations. As with their hosts, some invaded range populations showed genetic variation diagnostic of Balkan sources, supporting the Host Pursuit Hypothesis. In contrast, other invading populations had an Iberian origin, unlike their hosts in northern Europe, supporting the Host Shift Hypothesis. Finally, both British and Italian M. stigmatizans populations show signatures compatible with the Introduction Hypothesis from eastern Mediterranean sources. CONCLUSIONS:These data reveal the continental scale of multi-trophic impacts of anthropogenic disturbance and highlight the fact that herbivores and their natural enemies may face very different constraints on range expansion. The ability of natural enemies to exploit ecologically-similar hosts with which they have had no historical association supports a major role for ecological sorting processes in the recent assembly of these communities. The multitude of origins of invading natural enemy populations in this study emphasises the diversity of mechanisms requiring consideration when predicting consequences of other biological invasions or biological control introductions.
| S-EPMC2974729 | biostudies-literature
Project description:Biological diversity is the basis for, and an indicator of biosphere integrity. Together with climate change, its loss is one of the two most important planetary boundaries. A halt in biodiversity loss is one of the UN Sustainable Development Goals. Current changes in biodiversity in the vast landmass of Siberia are at an initial stage of inventory, even though the Siberian environment is experiencing rapid climate change, weather extremes and transformation of land use and management. Biodiversity changes affect traditional land use by Indigenous People and multiple ecosystem services with implications for local and national economies. Here we review and analyse a large number of scientific publications, which are little known outside Russia, and we provide insights into Siberian biodiversity issues for the wider international research community. Case studies are presented on biodiversity changes for insect pests, fish, amphibians and reptiles, birds, mammals and steppe vegetation, and we discuss their causes and consequences.
| S-EPMC8497665 | biostudies-literature
Project description:The data presented in this article are related to the research article entitled "Pollen spectrum, a cornerstone for tracing the evolution of the eastern central Asian desert" (JQSR 5260) (Lu et al., 2018) [1] In this paper, we supply a dataset, which provides a descriptive and general summary of pollen characteristic of desert dominant species in the eastern arid central Asia (ACA). The other important component is the illustration on pollen grains traits under light microscopy (LM) and scanning electron microscopy (SEM). Pollen grains of 56 species are extracted from voucher specimens from the PE herbarium at the Institute of Botany. It is worth noting that these species own special distribution patterns in China. The distribution maps are plotted using the Google Maps and the species distribution data at the county level supplied by the Chinese Virtual Herbarium (http://www.cvh.ac.cn/).
| S-EPMC5996618 | biostudies-literature