scholarly journals Metabarcoding to establish freshwater indicators of environmental degradation in the Indo-Burmese biodiversity hotspot

2021 ◽  
Vol 4 ◽  
Author(s):  
Alfried Vogler ◽  
Md. Mizanur Rahman ◽  
Alfred Burian ◽  
Thomas Creedy

Biodiversity hotspots of the world are increasingly exposed to anthropogenic pressures and resulting ecosystem breakdowns. However, biotic surveys for ecological status assessment are rarely conducted in poorly characterised, yet highly diverse ecosystems in the tropics and subtropics. Here, we addressed the challenge of developing a monitoring system for the highland streams of the Indo-Burmese biodiversity hotspot in Bangladesh, using a meta-barcoding approach to investigate the impacts of growing anthropogenic pressures on poorly studied invertebrate communities. Species richness and beta diversity in the region were correlated with anthropogenic stressors that varied greatly between sampling sites. A partial-network approach allowed us to identify potential indicator species for either a good or poor ecological status. Overall, our results document high species richness and pronounced responses to disturbance in these unexplored, but threatened habitats. In combination with classical taxonomy approaches, metabarcoding can therefore serve as a valuable tool to rapidly generate lacking baseline information facilitating the conservation of vulnerable ecosystems.

2007 ◽  
Vol 274 (1618) ◽  
pp. 1567-1574 ◽  
Author(s):  
Kevin J Gaston ◽  
Richard G Davies ◽  
C. David L Orme ◽  
Valerie A Olson ◽  
Gavin H Thomas ◽  
...  

Despite its wide implications for many ecological issues, the global pattern of spatial turnover in the occurrence of species has been little studied, unlike the global pattern of species richness. Here, using a database on the breeding distributions of birds, we present the first global maps of variation in spatial turnover for an entire taxonomic class, a pattern that has to date remained largely a matter of conjecture, based on theoretical expectations and extrapolation of inconsistent patterns from different biogeographic realms. We use these maps to test four predictions from niche theory as to the form that this variation should take, namely that turnover should increase with species richness, towards lower latitudes, and with the steepness of environmental gradients and that variation in turnover is determined principally by rare (restricted) species. Contrary to prediction, we show that turnover is high both in areas of extremely low and high species richness, does not increase strongly towards the tropics, and is related both to average environmental conditions and spatial variation in those conditions. These results are closely associated with a further important and novel finding, namely that global patterns of spatial turnover are driven principally by widespread species rather than the restricted ones. This complements recent demonstrations that spatial patterns of species richness are also driven principally by widespread species, and thus provides an important contribution towards a unified model of how terrestrial biodiversity varies both within and between the Earth's major land masses.


2016 ◽  
Vol 109 (1) ◽  
pp. 409-418 ◽  
Author(s):  
Aurélie Blanfuné ◽  
Charles François Boudouresque ◽  
Marc Verlaque ◽  
Sajmir Beqiraj ◽  
Lefter Kashta ◽  
...  

2015 ◽  
Vol 26 (4) ◽  
pp. 48-55 ◽  
Author(s):  
Aleksandra Bielczyńska

Abstract Diatoms are widely used for bioindication because of their sensitivity to anthropogenic pressures (e.g. eutrophication or acidity of waters). In many countries in the world, work has been undertaken to develop and implement diatom indices. Since 2000, in the Member States of the European Union, this has been done as part of the implementation of the Water Framework Directive. The results of lake assessment obtained using the Polish method based on epiphytic diatoms (IOJ - Indeks Okrzemkowy Jezior = the Diatom Index for Lakes) are greatly different from those provided by the other ecological status assessment methods. The purpose of this article is to review the scientific literature on the use of phytobenthos for bioindication in order to identify the advantages and disadvantages of the Polish IOJ method and to indicate the possible directions of improvements in this method. The literature evidencing the variability of phytobenthos related to its habitat, the spatial variability at the scale of a lake and the variability in the growing season was reviewed. The cited writings indicate that the further specification of guidelines for the sampling procedure and an increase in the number of survey sites could enhance the functionality of the Polish lake assessment method. It has also been suggested that it may be useful to test the effect of the seasonal variability of a phytobenthos assemblage on its bioindicator value.


2017 ◽  
Vol 11 (1) ◽  

With the exponential rise of human activities in the past decades, majority of studies conducted in Taal Volcano Protected Landscape (TVPL) are geared towards the conservation and preservation of Lake Taal’s remaining biodiversity. However, the current structure and assemblage of its terrestrial biotic communities remain relatively unstudied. In this study, we conducted biodiversity censuses in the four sites in TVPL to provide baseline information regarding the community structure of the selected study sites. Comparison of the plant diversity in Taal Volcano Crater Island and Romandan Falls within the forested areas of Mataas na Kahoy, Batangas reveal that both sites support remarkably different vegetation, with the former supporting a smaller floral diversity. The fairly small number of animal samples present difficulty in providing conclusive findings to the wildlife structure of the two study sites. However, the presence of 11 animal species exhibit valuable results in determining the ecological status of TVPL. It is deduced that several ecological barriers exist between the sites, which is attributed to their unique terrestrial biota.


Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 223
Author(s):  
Dāvis Ozoliņš ◽  
Agnija Skuja ◽  
Jolanta Jēkabsone ◽  
Ilga Kokorite ◽  
Andris Avotins ◽  
...  

Highly humic lakes are typical for the boreal zone. These unique ecosystems are characterised as relatively undisturbed habitats with brown water, high acidity, low nutrient content and lack of macrophytes. Current lake assessment methods are not appropriate for ecological assessment of highly humic lakes because of their unique properties and differing human pressures acting on these ecosystems. This study proposes a new approach suitable for the ecological status assessment of highly humic lakes impacted by hydrological modifications. Altogether, 52 macroinvertebrate samples from 15 raised bog lakes were used to develop the method. The studied lakes are located in the raised bogs at the central and eastern parts of Latvia. Altered water level was found as the main threat to the humic lake habitats since no other pressures were established. A multimetric index based on macroinvertebrate abundance, littoral and profundal preferences, Coleoptera taxa richness and the Biological Monitoring Working Party (BMWP) Score is suggested as the most suitable tool to assess the ecological quality of the highly humic lakes.


Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 918 ◽  
Author(s):  
Oscar Belmar ◽  
Carles Ibáñez ◽  
Ana Forner ◽  
Nuno Caiola

Designing environmental flows in lowland river sections and estuaries is a challenge for researchers and managers, given their complexity and their importance, both for nature conservation and economy. The Ebro River and its delta belong to a Mediterranean area with marked anthropogenic pressures. This study presents an assessment of the relationships between mean flows (discharges) computed at different time scales and (i) ecological quality based on fish populations in the lower Ebro, (ii) bird populations, and (iii) two shellfish fishery species of socioeconomic importance (prawn, or Penaeus kerathurus, and mantis shrimp, or Squilla mantis). Daily discharge data from 2000 to 2015 were used for analyses. Mean annual discharge was able to explain the variation in fish-based ecological quality, and model performance increased when aquatic vegetation was incorporated. Our results indicate that a good ecological status cannot be reached only through changes on discharge, and that habitat characteristics, such as the coverage of macrophytes, must be taken into account. In addition, among the different bird groups identified in our study area, predators were related to river discharge. This was likely due to its influence on available resources. Finally, prawn and mantis shrimp productivity were influenced up to a certain degree by discharge and physicochemical variables, as inputs from rivers constitute major sources of nutrients in oligotrophic environments such as the Mediterranean Sea. Such outcomes allowed revisiting the environmental flow regimes designed for the study area, which provides information for water management in this or in other similar Mediterranean zones.


2011 ◽  
Vol 8 (3) ◽  
pp. 397-400 ◽  
Author(s):  
Jake L. Snaddon ◽  
Edgar C. Turner ◽  
Tom M. Fayle ◽  
Chey V. Khen ◽  
Paul Eggleton ◽  
...  

The exceptionally high species richness of arthropods in tropical rainforests hinges on the complexity of the forest itself: that is, on features such as the high plant diversity, the layered nature of the canopy and the abundance and the diversity of epiphytes and litter. We here report on one important, but almost completely neglected, piece of this complex jigsaw—the intricate network of rhizomorph-forming fungi that ramify through the vegetation of the lower canopy and intercept falling leaf litter. We show that this litter-trapping network is abundant and intercepts substantial amounts of litter (257.3 kg ha −1 ): this exceeds the amount of material recorded in any other rainforest litter-trapping system. Experimental removal of this fungal network resulted in a dramatic reduction in both the abundance (decreased by 70.2 ± 4.1%) and morphospecies richness (decreased by 57.4 ± 5.1%) of arthropods. Since the lower canopy levels can contain the highest densities of arthropods, the proportion of the rainforest fauna dependent on the fungal networks is likely to be substantial. Fungal litter-trapping systems are therefore a crucial component of habitat complexity, providing a vital resource that contributes significantly to rainforest biodiversity.


2012 ◽  
Vol 279 (1742) ◽  
pp. 3520-3526 ◽  
Author(s):  
Brian Tilston Smith ◽  
Amei Amei ◽  
John Klicka

Climatic and geological changes across time are presumed to have shaped the rich biodiversity of tropical regions. However, the impact climatic drying and subsequent tropical rainforest contraction had on speciation has been controversial because of inconsistent palaeoecological and genetic data. Despite the strong interest in examining the role of climatic change on speciation in the Neotropics there has been few comparative studies, particularly, those that include non-rainforest taxa. We used bird species that inhabit humid or dry habitats that dispersed across the Panamanian Isthmus to characterize temporal and spatial patterns of speciation across this barrier. Here, we show that these two assemblages of birds exhibit temporally different speciation time patterns that supports multiple cycles of speciation. Evidence for these cycles is further corroborated by the finding that both assemblages consist of ‘young’ and ‘old’ species, despite dry habitat species pairs being geographically more distant than pairs of humid habitat species. The matrix of humid and dry habitats in the tropics not only allows for the maintenance of high species richness, but additionally this study suggests that these environments may have promoted speciation. We conclude that differentially expanding and contracting distributions of dry and humid habitats was probably an important contributor to speciation in the tropics.


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