Invertebrate responses to land use in tropical streams: discrimination of impacts enhanced by analysis of discrete areas

2019 ◽  
Vol 70 (4) ◽  
pp. 563
Author(s):  
Richard G. Pearson ◽  
Niall Connolly ◽  
Lee J. Benson ◽  
Andi Cairns ◽  
Paul Clayton ◽  
...  
Keyword(s):  
Land Use ◽  
Environmental Gradients ◽  
Detailed Comparison ◽  
Ecological Condition ◽  
Sensitivity Index ◽  
Riparian Management ◽  
Explanatory Variables ◽  
Taxa Richness ◽  
Tropical Australia ◽  
Local Impacts

We identified influences of land-use disturbances on invertebrate assemblages in streams draining eight areas of the Great Barrier Reef catchment in tropical Australia (~15.7–22°S), a region of high biodiversity. We used distance-based linear modelling (DistLM) to analyse assemblage data (103 taxa), richness and the SIGNAL2 taxon sensitivity index. DistLM of assemblages explained ~40% of variation across all samples and 7–54% of variation in individual areas. DistLM of richness and SIGNAL2 explained respectively 19–81 and 26–95% of variation. Explanatory variables were land use (especially cropping and grazing v. forest), riparian width, instream habitat, climate (drier south) and water quality (conductivity greater in south). Local impacts of activities such as mining were evident in models of individual areas. A detailed comparison of streams with contrasting riparian management demonstrated a 25% loss of richness, but no change in SIGNAL2 score. Accounting for local environmental gradients and using measures appropriate to the type of disturbance improved identification of impacts, and could form a framework for future regional monitoring of stream ecological condition. The impacts identified may be mitigated by remediation such as riparian rehabilitation, although management at catchment scales is required to be effective.

scholarly journals Correlating elements content in mosses collected in 2015 across Germany with spatially associated characteristics of sampling sites and their surroundings

2019 ◽  
Vol 31 (1) ◽  
Author(s):  
Stefan Nickel ◽  
Winfried Schröder
Keyword(s):  
Land Use ◽  
Population Density ◽  
Atmospheric Deposition ◽  
Vegetation Structure ◽  
Urban Areas ◽  
Explanatory Power ◽  
Spatial Density ◽  
Area Index ◽  
Explanatory Variables ◽  
Tree Layer

Abstract Background The aim of the study was a statistical evaluation of the statistical relevance of potentially explanatory variables (atmospheric deposition, meteorology, geology, soil, topography, sampling, vegetation structure, land-use density, population density, potential emission sources) correlated with the content of 12 heavy metals and nitrogen in mosses collected from 400 sites across Germany in 2015. Beyond correlation analysis, regression analysis was performed using two methods: random forest regression and multiple linear regression in connection with commonality analysis. Results The strongest predictor for the content of Cd, Cu, Ni, Pb, Zn and N in mosses was the sampled species. In 2015, the atmospheric deposition showed a lower predictive power compared to earlier campaigns. The mean precipitation (2013–2015) is a significant factor influencing the content of Cd, Pb and Zn in moss samples. Altitude (Cu, Hg and Ni) and slope (Cd) are the strongest topographical predictors. With regard to 14 vegetation structure measures studied, the distance to adjacent tree stands is the strongest predictor (Cd, Cu, Hg, Zn, N), followed by the tree layer height (Cd, Hg, Pb, N), the leaf area index (Cd, N, Zn), and finally the coverage of the tree layer (Ni, Cd, Hg). For forests, the spatial density in radii 100–300 km predominates as significant predictors for Cu, Hg, Ni and N. For the urban areas, there are element-specific different radii between 25 and 300 km (Cd, Cu, Ni, Pb, N) and for agricultural areas usually radii between 50 and 300 km, in which the respective land use is correlated with the element contents. The population density in the 50 and 100 km radius is a variable with high explanatory power for all elements except Hg and N. Conclusions For Europe-wide analyses, the population density and the proportion of different land-use classes up to 300 km around the moss sampling sites are recommended.

scholarly journals Generalized linear models with random effects for the description of data with excess zeros

2011 ◽  
Vol 54 (6) ◽  
pp. 661-675
Author(s):  
N. Mielenz ◽  
K. Thamm ◽  
M. Bulang ◽  
J. Spilke
Keyword(s):  
Random Effects ◽  
Negative Binomial Distribution ◽  
Binomial Distribution ◽  
Linear Models ◽  
Negative Binomial ◽  
Detailed Comparison ◽  
Response Scale ◽  
Explanatory Variables ◽  
Excess Zeros ◽  
Explanatory Factors

Abstract. In this paper count data with excess zeros and repeated observations per subject are evaluated. If the number of values observed for the zero event in the trial substantially exceeds the expected number (derived from the Poisson or from the negative binomial distribution), then there is an excess of zeros. Hurdle and zero-inflated models with random effects are available in order to evaluate this type of data. In this paper both model approaches are presented and are used for the evaluation of the number of visits to the feeder per cow per hour. Finally, for the analysis of the target trait a hurdle model with random effects based on a negative binomial distribution was used. This analysis was derived from a detailed comparison of models and was needed because of a simpler computer implementation. For improved interpretation of the results, the levels of the explanatory factors (for example, the classes of lactation) were not averaged in the link scale, but rather in the response scale. The deciding explanatory variables for the pattern of visiting activities in the 24-hour cycle are the milking and cleaning times at hours 4, 7, 12 and 20. The highly significant differences in the visiting frequencies of cows of the first lactation and those of higher lactations were explained by competition for access to the feeder and thus to the feed.

scholarly journals Land use changes in the hinterland of major Slovak cities

Geografie ◽  
2010 ◽  
Vol 115 (4) ◽  
pp. 413-439 ◽  
Author(s):  
Martin Šveda ◽  
Daniela Vigašová
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Spatial Structure ◽  
Land Use Changes ◽  
Detailed Comparison ◽  
Land Use Land Cover ◽  
Residential Areas ◽  
Shopping Centres ◽  
Agricultural Use ◽  
Land Types

The countryside around major Slovak cities is undergoing significant transformation. The construction of shopping centres, administrative buildings, logistical sites, residential areas and changes in the agricultural use of land are causing vast changes in land use (land cover). The objective of this paper is to examine changes in the spatial structure of land use in the hinterland of 11 Slovak cities, with more than 50 thousand inhabitants, during the period from 2000 to 2008. On the basis of a detailed comparison of data obtained from the Aggregated Areas of Land Types database (Úhrnné hodnoty druhov pozemkov) we analyzed changes in land use in 847 municipalities within the Functional Urban Regions of Bratislava, Košice, Prešov, Nitra, Žilina, Banská Bystrica, Trnava, Trenčín, Poprad and Prievidza. The results of the research confirmed significantly differentiated changes in land use. Whereas in the capital of Bratislava changes in land use are primarily caused by suburbanization, creating a relatively compact suburban zone, changes in land use were recorded only in selected sites in the rest of these major Slovak cities.

Impact of adjacent land use on the ecological condition of riparian habitats: The relation between condition and vegetation properties

2020 ◽  
Vol 23 (4) ◽  
pp. 610-621 ◽  
Author(s):  
Isela Zermeño‐Hernández ◽  
Julieta Benítez‐Malvido ◽  
Ireri Suazo‐Ortuño ◽  
Moisés Méndez‐Toribio
Keyword(s):  
Land Use ◽  
Ecological Condition ◽  
Riparian Habitats

Quantifying total and labile pools of soil organic carbon in cultivated and uncultivated soils in eastern India

Soil Research ◽  
2018 ◽  
Vol 56 (4) ◽  
pp. 413 ◽  
Author(s):  
Kumari Priyanka ◽  
Anshumali
Keyword(s):  
Land Use ◽  
Function Analysis ◽  
Land Use Changes ◽  
C Sequestration ◽  
Sensitivity Index ◽  
Organic C ◽  
Soil C ◽  
C Pools ◽  
The Impact ◽  
Land Use Practices

Loss of labile carbon (C) fractions yields information about the impact of land-use changes on sources of C inputs, pathways of C losses and mechanisms of soil C sequestration. This study dealt with the total organic C (TOC) and labile C pools in 40 surface soil samples (0–15 cm) collected from four land-use practices: uncultivated sites and rice–wheat, maize–wheat and sugarcane agro-ecosystems. Uncultivated soils had a higher total C pool than croplands. The soil inorganic C concentrations were in the range of 0.7–1.4 g kg–1 under different land-use practices. Strong correlations were found between TOC and all organic C pools, except water-extractable organic C and mineralisable C. The sensitivity index indicated that soil organic C pools were susceptible to changes in land-use practices. Discriminant function analysis showed that the nine soil variables could distinguish the maize–wheat and rice–wheat systems from uncultivated and sugarcane systems. Finally, we recommend crop rotation practices whereby planting sugarcane replenishes TOC content in soils.

scholarly journals Response of herbaceous vegetation functional diversity to land use change across five sites in Europe and Israel

2011 ◽  
Vol 57 (1-2) ◽  
pp. 53-72 ◽  
Author(s):  
Sandra Lavorel ◽  
Francesco de Bello ◽  
Karl Grigulis ◽  
Jan Lepš ◽  
Eric Garnier ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Functional Diversity ◽  
Linear Models ◽  
Current Knowledge ◽  
Environmental Gradients ◽  
Functional Divergence ◽  
Grassland Management ◽  
Community Response ◽  
Mixed Linear Models

Only a few studies have examined responses of grassland functional diversity to management and major environmental gradients, in order to address the question of whether grassland use can promote functional divergence. For five grassland sites in Israel, Portugal, the Czech Republic, Mediterranean France, and the French Alps, where traditional grassland management is being abandoned, we quantified community-weighted means (CWM) and functional divergence (FDvg) for the three Leaf-Height-Seed (LHS) traits, individually and in combination. Responses of CWM and FDvg to land use were analyzed by mixed linear models with aridity, phosphorus, fertility, and the fractions of grasses and annuals as covariates.Responses of community-weighted traits to land use were consistent with current knowledge. More intense management favored plants with more rapid resource acquisition (high Specific Leaf Area, or SLA), whereas abandonment or less intense grassland management increased the dominance by tall plants with more conservative strategies (low SLA). Seed weight did not respond to land use. For the three traits and their combination, functional divergence decreased in response to land use change overall. Detailed responses, however, varied depending on sites and especially their climate. At the two French sites, traditional site management promoted functional divergence within communities by suppressing dominance by large perennial tussocks, whereas at the two Mediterranean sites it is likely that the drier climate promoted a functionally diverse pool of species tolerant to grazing.This study demonstrates how simultaneous analyses of variations in community-mean traits and functional divergence for a focused set of traits offer promising avenues to understand mechanisms of community response to environmental change.

scholarly journals Microplastics and anthropogenic fibre concentrations in lakes reflect surrounding land use

PLoS Biology ◽  
2021 ◽  
Vol 19 (9) ◽  
pp. e3001389
Author(s):  
Andrew J. Tanentzap ◽  
Samuel Cottingham ◽  
Jérémy Fonvielle ◽  
Isobel Riley ◽  
Lucy M. Walker ◽  
...  
Keyword(s):  
Land Use ◽  
Wastewater Treatment ◽  
Surface Waters ◽  
Water Retention ◽  
Forest Cover ◽  
Field Survey ◽  
Environmental Gradients ◽  
Waste Production ◽  
Future Work ◽  
Local Hydrology

Pollution from microplastics and anthropogenic fibres threatens lakes, but we know little about what factors predict its accumulation. Lakes may be especially contaminated because of long water retention times and proximity to pollution sources. Here, we surveyed anthropogenic microparticles, i.e., microplastics and anthropogenic fibres, in surface waters of 67 European lakes spanning 30° of latitude and large environmental gradients. By collating data from >2,100 published net tows, we found that microparticle concentrations in our field survey were higher than previously reported in lakes and comparable to rivers and oceans. We then related microparticle concentrations in our field survey to surrounding land use, water chemistry, and plastic emissions to sites estimated from local hydrology, population density, and waste production. Microparticle concentrations in European lakes quadrupled as both estimated mismanaged waste inputs and wastewater treatment loads increased in catchments. Concentrations decreased by 2 and 5 times over the range of surrounding forest cover and potential in-lake biodegradation, respectively. As anthropogenic debris continues to pollute the environment, our data will help contextualise future work, and our models can inform control and remediation efforts.

scholarly journals Integrating Ecosystem Service Values and Economic Benefits for Sustainable Land Use Management in Semi-Arid Regions in Northern China

2021 ◽  
Vol 13 (18) ◽  
pp. 10431
Author(s):  
Honglei Jiang ◽  
Xia Xu ◽  
Lingfei Wang ◽  
Tong Zhang
Keyword(s):  
Land Use ◽  
Process Model ◽  
Spatial Configuration ◽  
Northern China ◽  
Economic Benefits ◽  
Ecological Condition ◽  
Sustainable Land Use ◽  
Land Resources ◽  
Land Use Optimization ◽  
S Model

Studies on land use structural optimization can support the sustainability of land resources. The Taipusi Banner lies in the arid and semiarid area of northern China, with rapid economic development and a vulnerable ecological condition. Taking the Taipusi Banner as a research case, we adopted a land use map and statistical data, and employed the ecosystem process model to establish five scenarios, including an economically optimal scenario, an ecologically optimal scenario, a comprehensively optimal scenario, a status quo, and a projected scenario. Based on multi-objective linear programming, the land use demand was optimized; then, the CLUE-S model and adaptability evaluation were adopted to establish spatial patterns. The ecological and economic benefits were then analyzed and policy suggestions are provided. The main results include the following: (1) The optimization outputs of various scenarios show that under optimization, cropland and forestland increased by 9.13% and 18.9%, respectively, and grassland decreased by 9.81%. (2) The land use optimization shows that comprehensive optimization aimed at achieving comprehensive benefits, ecological benefits, and economic benefits increased these benefits by 3.89%, 2.1%, and 6.2%, respectively. Compared with other scenarios, focusing on the comprehensive benefits of land use can result in the greatest increase in benefits to improve sustainability land resources. Land use optimization must consider not only the optimization of both the quantity and configuration but also the dimensions of both ecology and the economy. Land use should be based on a land suitability evaluation and optimization of the land use spatial configuration to update ineffective land uses and should gradually adjust both the ecological and engineering measures.

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