Land use change causes environmental homogeneity and low beta-diversity in Heteroptera of streams

2020 ◽  
Vol 56 ◽  
pp. 9 ◽  
Author(s):  
Karina Dias-Silva ◽  
Leandro Schlemmer Brasil ◽  
Geysa Kelly Oliveira Veloso ◽  
Helena Soares Ramos Cabette ◽  
Leandro Juen
Keyword(s):  
Beta Diversity ◽  
Riparian Vegetation ◽  
Environmental Changes ◽  
Aquatic Communities ◽  
Generalist Species ◽  
Environmental Variations ◽  
Environmental Integrity ◽  
Physical Changes ◽  
Topic Understanding ◽  
Better Than

Although species distribution pattern is a widely discussed topic, understanding the mechanisms that drive it in time and space is still one of the central goals of ecology. Moreover, it is of the most importance to discuss the maintenance of this biodiversity and the services it provides. Therefore, our aim is to test the following hypotheses: 1) Preserved environments have higher beta-diversity than environments with lower preservation values, since beta-diversity is determined by environmental variations between habitats; 2) Beta-diversity will be better than species richness to detect changes in community regarding environmental integrity gradients. This will occur because richness is not sensitive to changes in composition and this might mask results when sensitive species are lost and generalist species are introduced into the altered environments. In order to test these hypotheses, 20 points were sampled in five streams of the Brazilian Cerrado with different integrity conditions. Environmental change did not affect Heteroptera richness; however, it affected the beta-diversity of the group as a whole and of Nepomorpha, also negatively affecting both Gerromorpha beta-diversity and richness. Moreover, there was difference in variation of Gerromorpha composition in altered and degraded sites, but there was no effect on Nepomorpha. These results show that Gerromorpha is more sensitive to physical changes in streams caused by the loss of environmental integrity. Therefore, environmental changes with no regard to riparian vegetation boundaries causes shifts in stream conditions and changes aquatic communities, which places at risk the ecosystems services provided by these communities.

Nestedness of insect assemblages in agriculture-impacted Atlantic forest streams

2020 ◽  
Vol 56 ◽  
pp. 3
Author(s):  
Júlio Cesar Serrano Huiñocana ◽  
Edélti Faria Albertoni ◽  
Rayana Caroline Picolotto ◽  
Silvia Vendruscolo Milesi ◽  
Luiz Ubiratan Hepp
Keyword(s):  
Land Use ◽  
Atlantic Forest ◽  
Beta Diversity ◽  
Riparian Vegetation ◽  
Agricultural Land ◽  
Aquatic Insect ◽  
Agricultural Land Use ◽  
Agricultural Intensity ◽  
Environmental Integrity ◽  
Forest Streams

Agricultural land use causes habitats fragmentation and riparian vegetation removal, driving variability in the composition of aquatic insect assemblage in streams. We explored the effect of agriculture on the beta diversity of insect assemblages of Ephemeroptera, Plecoptera and Trichoptera (EPT) in Atlantic forest streams. We measured water physical and chemical variables and quantified the land cover of 10 stream catchments to determine the environmental integrity of the streams. The percentage of vegetation range was ∼6% to ∼47%, and agricultural land use range was ∼24% to ∼88%. We collected a total of 2632 individuals distributed in 30 genera. Trichoptera was the most abundant order (57%), followed by Ephemeroptera (41%) and Plecoptera (2%). The abundance was influenced by the higher agriculture practices in the streams adjacent areas. On the other hand, the oxygenated waters and higher percentages of riparian vegetation influenced the EPT rarefied richness. The beta diversity of EPT assemblages was structured by nestedness due to the influence agricultural activities. The variation in the agricultural intensity that occurs in the streams generated more intense limnological variability, which caused the nestedness of EPT insects as well as the reduction of taxonomic richness. Thus, the streams with low environmental integrity had EPT assemblages nested in streams of high environmental integrity.

scholarly journals Determinants of bird assemblage composition in riparian vegetation on sugarcane farms in the Queensland Wet Tropics

2015 ◽  
Vol 21 (1) ◽  
pp. 60 ◽  
Author(s):  
Anita F. Keir ◽  
Richard G. Pearson ◽  
Robert A. Congdon
Keyword(s):  
Riparian Vegetation ◽  
Wildlife Conservation ◽  
Agricultural Landscape ◽  
Riparian Zone ◽  
Riparian Forest ◽  
Agricultural Landscapes ◽  
Generalist Species ◽  
Assemblage Composition ◽  
Bird Assemblages ◽  
Wet Tropics

Remnant habitat patches in agricultural landscapes can contribute substantially to wildlife conservation. Understanding the main habitat variables that influence wildlife is important if these remnants are to be appropriately managed. We investigated relationships between the bird assemblages and characteristics of remnant riparian forest at 27 sites among sugarcane fields in the Queensland Wet Tropics bioregion. Sites within the remnant riparian zone had distinctly different bird assemblages from those of the forest, but provided habitat for many forest and generalist species. Width of the riparian vegetation and distance from source forest were the most important factors in explaining the bird assemblages in these remnant ribbons of vegetation. Gradual changes in assemblage composition occurred with increasing distance from source forest, with species of rainforest and dense vegetation being replaced by species of more open habitats, although increasing distance was confounded by decreasing riparian width. Species richness increased with width of the riparian zone, with high richness at the wide sites due to a mixture of open-habitat species typical of narrower sites and rainforest species typical of sites within intact forest, as a result of the greater similarity in vegetation characteristics between wide sites and the forest proper. The results demonstrate the habitat value for birds of remnant riparian vegetation in an agricultural landscape, supporting edge and open vegetation species with even narrow widths, but requiring substantial width (>90 m) to support specialists of the closed forest, the dominant original vegetation of the area.

scholarly journals New kid on the block: Research of alpine-lake macroinvertebrates in the Tatra Mountains enhanced by DNA barcoding and metabarcoding

2021 ◽  
Vol 4 ◽  
Author(s):  
Ondrej Vargovčík ◽  
Zuzana Čiamporová-Zaťovičová ◽  
Fedor Čiampor Jr
Keyword(s):  
Large Scale ◽  
Environmental Changes ◽  
Human Impacts ◽  
Sampling Error ◽  
Alpine Lakes ◽  
Alpine Lake ◽  
Tatra Mountains ◽  
Aquatic Communities ◽  
Wide Range ◽  
The Tatra Mountains

State of ecosystems and biodiversity protection are becoming the key interests for modern society due to climate change and negative human impacts (Leese 2018). Environmental changes in freshwaters are indicated also by benthic communities, especially in sensitive ecosystems like alpine lakes (Fjellheim 2009). Moreover, remoteness and isolation of alpine lakes make them a source of biodiversity, which is worth conserving (Hamerlík 2014). A promising tool for efficient large-scale monitoring of aquatic communities is DNA metabarcoding (Leese 2018). In this study, we applied metabarcoding to analyse macrozoobenthos of 12 lakes in the Tatra Mountains, using benthic bulk samples and eDNA filtered from water (Fig. 1). In compliance with recent publications, eDNA amplified with BF3/BR2 primers resulted in high percentage of non-invertebrate reads (Leese 2021). Based on in silico tests with the obtained sequences, we confirm that the recently developed EPTDr2n primer enables minimizing non-target amplification even with eDNA filtered from alpine-lake water (Elbrecht and Leese 2017). This ability is facilitated by 3’ end of the primer and we observed the two important mismatches in non-target sequences from our study (Leese 2021). Thus, our future analyses of eDNA (and bulk-sample fixative) will benefit from the new primer. Concerning bulk samples, a wide range of invertebrate taxa was assigned to the OTUs and they showed good congruence with previous studies using morphological determination (e.g. Krno 2006). Certain differences with (and among) the previous records per lake were observed, which could suggest ecological changes, but at the moment the influence of sampling error cannot be excluded. In eDNA, several taxa were congruent with the previous records, but their amount and read abundance was considerably lower due to non-target amplification. Apart from that, filling gaps in barcoding databases remains one of our priorities, as identification to species or genus level was not yet possible for some invertebrate OTUs. In addition, we subjected the NGS data to denoising and abundance-filtering in order to explore haplotype-level diversity (Andújar 2021). Although more comprehensive conclusions will be possible only after obtaining data from more lakes and years, already the two metabarcoding experiments presented here enabled us to efficiently detect within-species genetic diversity and identify a large variety of taxa, including groups that would otherwise be omitted or very challenging to identify. This underlines the potential of DNA methods to provide valuable ecological and biodiversity data across the tree of life for modern biomonitoring. This study was realized with support from VEGA 2/0030/17 and VEGA 2/0084/21.

scholarly journals A Suppression Method of Concentration Background Noise by Transductive Transfer Learning for a Metal Oxide Semiconductor-Based Electronic Nose

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1913
Author(s):  
Huixiang Liu ◽  
Qing Li ◽  
Zhiyong Li ◽  
Yu Gu
Keyword(s):  
Transfer Learning ◽  
Environmental Changes ◽  
Oxide Semiconductor ◽  
Target Domain ◽  
Fisher Linear Discriminant ◽  
Linear Discriminant ◽  
Signal Features ◽  
Changes Over Time ◽  
Independence Criterion ◽  
Better Than

Signal drift caused by sensors or environmental changes, which can be regarded as data distribution changes over time, is related to transductive transfer learning, and the data in the target domain is not labeled. We propose a method that learns a subspace with maximum independence of the concentration features (MICF) according to the Hilbert-Schmidt Independence Criterion (HSIC), which reduces the inter-concentration discrepancy of distributions. Then, we use Iterative Fisher Linear Discriminant (IFLD) to extract the signal features by reducing the divergence within classes and increasing the divergence among classes, which helps to prevent inconsistent ratios of different types of samples among the domains. The effectiveness of MICF and IFLD was verified by three sets of experiments using sensors in real world conditions, along with experiments conducted in the authors’ laboratory. The proposed method achieved an accuracy of 76.17%, which was better than any of the existing methods that publish their data on a publicly available dataset (the Gas Sensor Drift Dataset). It was found that the MICF-IFLD was simple and effective, reduced interferences, and deftly managed tasks of transfer classification.

The Holocene record of environmental changes in the ‘Stagno di Maccarese’ marsh (Tiber river delta, central Italy)

The Holocene ◽  
2012 ◽  
Vol 22 (12) ◽  
pp. 1461-1471 ◽  
Author(s):  
C Giraudi
Keyword(s):  
Environmental Changes ◽  
Central Italy ◽  
Global Scale ◽  
Beach Ridges ◽  
The Holocene ◽  
Tiber River ◽  
Environmental Variations ◽  
Holocene Record ◽  
The 19Th Century ◽  
Ird Events

The stratigraphic study of the Stagno di Maccarese, carried out on the sediments exposed in about 7 km of trenches excavated in an area of approximately 1.5 km2, has shown that in the course of the Holocene many environmental variations have taken place. The complex evolution of the marsh is demonstrated by the variations in water salinity and the presence of erosion surfaces and soils between the sediments. In the early Holocene, the area studied was an isolated marsh with water having variable salinity, and it was only about 6000 cal. yr BP that it was encompassed in the system of inner delta marshes. In the delta environment, the water of the marsh was oligohaline until about 9th–8th centuries bc, brackish from 9th–8th centuries bc to about 600 yr BP, and later oligohaline until the 19th century drainage. A number of environmental variations are connected with local phenomena, such as erosion of the beach ridges and Tiber floods, but the others can be correlated chronologically with climatic events recorded at regional and global scale. The millennial variations seem to be connected with changes in insolation, while abrupt variations can be correlated chronologically with the IRD events dated at 8200, 5900, 4200, 2800, 1400 and 500 cal. yr BP.

Using photographs to document environmental change: the effects of dams on the riparian environment of the lower Ord River

2002 ◽  
Vol 50 (4) ◽  
pp. 465 ◽  
Author(s):  
A. N. Start ◽  
T. Handasyde
Keyword(s):  
Environmental Change ◽  
Western Australia ◽  
Water Allocation ◽  
Riparian Vegetation ◽  
Aquatic Communities ◽  
Tree Component ◽  
Woodland Communities ◽  
Large Floods ◽  
Allocation Plans

A series of photographs, mostly taken between 1952 and 1990 at three sites on the lower Ord River, Kimberley Region, Western Australia, was used to demonstrate that photographs can be used to describe environmental change in situations where there are no documented records. This study examined changes to riparian vegetation caused by the construction of two dams. The study has important implications for development of water allocation plans. In the post-dam era, relative hydrological stability brought about by curtailment of large floods and provision of perpetual flow in a once-seasonal river has allowed extensive development of emergent aquatic and fringing woodland communities throughout the study reach. The emergent aquatic communities and most of their component species were previously absent but the tree component of fringing woodland communities comprises species that were present before the dams were constructed, albeit in isolated, sheltered pockets. Limitations to the use of photographs included absence of any images through the first 50 years of pastoral use of the area, limited number of sites that attracted photographers and limits to the discernible detail (e.g. identity of species, even most trees, in landscape images).

scholarly journals Changes in the structure of bird communities over 10 years in the Ecological Corridor of Paraguay River, Pantanal wetland

2021 ◽  
Vol 12 (3) ◽  
pp. 111-125
Author(s):  
Rafaella Ferreira Neres de Queiroz ◽  
Breno Dias Vitorino ◽  
Angélica Vilas Boas da Frota ◽  
Carolina Joana da Silva ◽  
Solange Kimie Ikeda Castrillon ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Hydrological Cycle ◽  
Bird Community ◽  
Bird Communities ◽  
Time Interval ◽  
Sampling Point ◽  
Generalist Species ◽  
Paraguay River ◽  
Temporal Space ◽  
Effective Decision Making

Studies with bird communities related to the hydrogeomorphological characteristics of climatic rivers associated with flood areas are important to identify short and long term temporal space changes. In this perspective, this research aims to evaluate the structure of the bird community of the Paraguay River, through the richness of descriptors, the quantity and the diversity and equability index over an interval of 10 years, 2008 / 9-2018 / 19 , considering the economies of the hydrological cycle, floods, floods, emptiness and drought and sampled macrohabitats. The study was developed addressing a connected hydrology of the Paraguay River, in the longitudinal and lateral dimensions. A study area comprised of three functional sectors of the Paraguay River, meandering, rectilinear and transitional, beginning in the urban period of the municipality of Cáceres-MT, up to a Descalvada Farm, with a 134 km course of the river, with 13 points in total. Each functional sector of the river, had a sampling point and 10 parental bays, with different degrees of lateral connectivity, were sampled. A survey analyzed and compared two hydrological sampling cycles, the first between June 2008 and March 2009, and the second between August 2018 and April 2019. The protocol for the sampling consisted of four campaigns corresponding to the hydrological drought studies, flood, full and ebb. The results pointed to a distinction in the community structure between the two cycles 2008/2009 - 2018/2019 show a difference in the relative scope and in the composition of the species in the sampled locations. The main change registered between the two cycles (2008/2009 and 2018/2019) was the disappearance of three nests - habitat for feeding and reproduction of colonial birds, identified in the first and without registration in the second cycle. The dominance of Mycteria americana is highlighted, a species sensitive to environmental changes, not observed in the first cycle of studies. The absence of nests in 2018/2019, coupled with the dominance of Pitangus sulphuratus, a generalist species, may indicate anthropic changes that occurred along the Paraguay River in this time interval. It is hoped that the results of this comparison will be able to subsidize or influence the effective decision-making for the conservation of the biodiversity of birds and the Paraguay and Pantanal river itself.

scholarly journals The Role of Common-Pool Resources’ Institutional Robustness in a Collective Action Dilemma under Environmental Variations.

2020 ◽  
Author(s):  
Ana Alicia Dipierri ◽  
Dimitrios Zikos
Keyword(s):  
Conflict Resolution ◽  
Group Dynamics ◽  
Water Availability ◽  
Environmental Variability ◽  
Irrigation System ◽  
Mitigation Measures ◽  
External Disturbances ◽  
Environmental Variations ◽  
Better Than

Extreme environmental variations (EV), as a phenomenon deriving from climate change (CC), led to an exacerbated uncertainty on water availability and increased the likelihood of conflicts regarding water-dependent activities such as agriculture. In this paper, we investigate the role of conflict resolution mechanisms -one of Ostrom’s acclaimed Design Principles (DPs)- when social-ecological systems (SESs) are exposed to physical external disturbances. The theoretical propositions predict that SESs with conflict-resolution-mechanisms will perform better than those without them. We tested this proposition through a framed-field-experiment that mimicked an irrigation system. In this asymmetric setting, farmers were exposed to two (2) dilemmas: (i) how much to invest in the communal irrigation system’s (CIS) maintenance and (ii) how much water to extract. The setting added a layer of complexity: water availability did not only depend on the investment but also on the environmental variability. Our findings largely confirmed the theoretical proposition: groups with stronger institutional robustness are able to cope with EV better than those with weaker robustness. However, we also found that some groups, despite lacking conflict-resolution-mechanisms, were also able to address EV. We explored potential explanatory variables to these unexpected results. We found that subjects’ and groups’ attributes might address uncertainty and avert conflict. Thus, SESs’ capacity to respond to external disturbances, such as EV, might not only be a question of DPs. Instead, it might also be strongly related to group members' attributes and group dynamics. Our results pave the way for further research, hinting that some groups might be better equipped for mitigation measures, while others might be better equipped for adaptation measures.

Measuring organisational resilience: small firms dealing with gas investment cycles

2016 ◽  
Vol 56 (2) ◽  
pp. 570
Author(s):  
Jerad Ford ◽  
Martie-Louise Verreynne ◽  
John Steen
Keyword(s):  
Small Firms ◽  
Regional Economy ◽  
Oil And Gas ◽  
Environmental Changes ◽  
Spillover Effects ◽  
Local Economy ◽  
Operational Phase ◽  
Capital Construction ◽  
Initial Results ◽  
Better Than

The capital construction phase of the CSG–LNG projects in Queensland has required significant investment in employment, and provided opportunities for local contractors with spillover effects for the regional economy. As these projects transition into the operational phase they will sustain a different supply chain profile, which has implications for the local economy. The authors’ primary question is, how do local business adapt to these changes? Initial results indicate that some businesses adapt better than others. The authors call these small to medium sized (SME) businesses resilient organisations. Building on data from a survey of SMEs in the gasfields, the authors show how resilient firms are able to learn, adapt, innovate and renew in response to these environmental changes. The findings suggest ways to support SMEs to adapt to the changes brought about by this economically important industry. The findings from this study also have wider implications for other regions in Australia and around the world that may encounter significant oil and gas investments in the future.

scholarly journals Modelling the risk of mortality of Corbicula fluminea (Müller, 1774) (Bivalvia: Corbiculidae) exposed to different turbidity conditions

2014 ◽  
Vol 74 (2) ◽  
pp. 509-514 ◽  
Author(s):  
WEP. Avelar ◽  
FF. Neves ◽  
MAS. Lavrador
Keyword(s):  
Environmental Changes ◽  
Corbicula Fluminea ◽  
Mortality Rates ◽  
Aquatic Communities ◽  
Water Turbidity ◽  
Erosion Processes ◽  
Risk Of Mortality ◽  
High Turbidity ◽  
Study Sites ◽  
The One

The provision of sediment in rivers, due to erosion processes that occur in the environment, consists of a major source of pollution and alteration of the physicochemical conditions of water resources. In addition, the increase in water turbidity may cause siltation, dramatically impacting aquatic communities. Specifically considering the bivalve Corbicula fluminea (Müller, 1774), the aim of this study was to analyse the effect of exposure to different turbidity conditions of sediments, as a risk factor for the animals. For this purpose, a docking device was designed to ensure water circulation in a closed system and to maintain the desired levels of turbidity. Although C. fluminea can generally tolerate environmental changes in aquatic systems, an intolerance to high turbidity levels was experimentally observed, expressed by the mortality rate of the animals when exposed to conditions above 150 nephelometric turbidity units (NTU). This value was similar to the one recorded at study sites in the rivers Pardo (Serrana-SP-Brazil) and Mogi Guaçu (Porto Ferreira-SP-Brazil) during the rainy season. Using a logistic regression model, the experimental results were analysed and the observed mortality rates indicate that the exposure of the animals to turbidity levels above 150 nephelometric turbidity units (NTU), for periods longer than 120 hours, may be considered a probable cause of mortality for the species.

Sign in / Sign up

Export Citation Format

Share Document