The relative role of environmental, spatial, and land-use patterns in explaining aquatic macrophyte community composition

2011 ◽  
Vol 68 (10) ◽  
pp. 1778-1789 ◽  
Author(s):  
Alison Mikulyuk ◽  
Sapna Sharma ◽  
Scott Van Egeren ◽  
Eric Erdmann ◽  
Michelle E. Nault ◽  
...  
Keyword(s):  
Land Use ◽  
Environmental Factors ◽  
Community Composition ◽  
Spatial Patterns ◽  
Aquatic Plant ◽  
Aquatic Macrophyte ◽  
Plant Distribution ◽  
Relative Role ◽  
Macrophyte Community

Quantifying the relative role of environmental and spatial factors to understand patterns in community composition is a fundamental goal of community ecology. We applied a tested and repeatable point-intercept sampling method to aquatic macrophyte assemblages in 225 Wisconsin lakes to understand the ability of environmental, land-use, and spatial patterns to explain aquatic plant distribution and abundance. Using a variation partitioning framework in conjunction with Moran eigenvector maps we found that environmental, land-use, and spatial patterns explained 31% of total adjusted variation in aquatic macrophyte assemblages across the landscape. Environmental factors were the most important (contributing 34% of the total explained variation), but all sources of variation were statistically significant. Community composition varied from north to south along a gradient of alkalinity and from disturbed to undisturbed lakes, diverging according to whether disturbance was urban or agricultural. The large amount of shared variation among predictor variables suggests causal relationships are complex and emphasizes the importance of considering space and land-use in addition to environmental factors when characterizing macrophyte assemblages. This work is the first to examine the joint and unique effects of environment, land-use, and spatial patterns on aquatic plant communities.

scholarly journals Spatial Variation in Bacterioplankton Communities in the Pearl River, South China: Impacts of Land Use and Physicochemical Factors

2020 ◽  
Vol 8 (6) ◽  
pp. 814
Author(s):  
Lei Zhou ◽  
Weiyuan Chen ◽  
Jijia Sun ◽  
Li Liu ◽  
Xiande Huang
Keyword(s):  
Land Use ◽  
Environmental Factors ◽  
Spatial Patterns ◽  
Agricultural Land ◽  
Anthropogenic Activities ◽  
Specific Conductivity ◽  
Pearl River ◽  
Physicochemical Factors ◽  
The Pearl River ◽  
Bacterioplankton Communities

River ecosystems are critical for human and environmental health, with bacterioplankton playing a vital role in biogeochemical cycles. Unveiling the spatial patterns of bacterioplankton communities in relation to environmental factors is important for understanding the processes of microbial variation and functional maintenance. However, our understanding of the correlations among bacterioplankton communities, physicochemical factors, and land use, especially in large rivers affected by intensive anthropogenic activities, remains relatively poor. Here, we investigated the bacterioplankton communities in July 2018 in three main tributaries of the Pearl River, i.e., Beijiang, Xijiang, and Pearl River Delta, based on 16S rRNA high-throughput sequencing. Results showed that the most dominant phyla, Proteobacteria, Actinobacteria, Cyanobacteria, and Planctomycetes accounted for 33.75%, 22.15%, 11.65%, and 10.48% of the total abundance, respectively. The bacterioplankton communities showed remarkable differences among the three tributaries in terms of composition, structure, diversity, and predictive functional profiles. Mantel and partial Mantel tests revealed that the bacterioplankton communities were affected by physicochemical variables (p < 0.01) and land use (p < 0.01). Redundancy analysis identified specific conductivity, dissolved oxygen, agricultural land, ammonium, urban land, and water transparency as the dominant environmental factors influencing the bacterioplankton communities in the Pearl River. Variation partitioning analysis indicated that both physicochemical factors and land use had direct effects on the bacterioplankton community, and that land use may also shape bacterioplankton communities through indirect effects of physicochemical factors on riverine ecosystems. This study provides fundamental information on the diversity, spatial patterns, and influencing factors of bacterioplankton communities in the Pearl River, which should enhance our understanding of how such communities change in response to environmental gradients and anthropogenic activities.

The role of land use and environmental factors on microbial pollution of mountainous limestone aquifers

2007 ◽  
Vol 55 (2) ◽  
pp. 277-283 ◽  
Author(s):  
V. Allocca ◽  
F. Celico ◽  
E. Petrella ◽  
G. Marzullo ◽  
G. Naclerio
Keyword(s):  
Land Use ◽  
Environmental Factors ◽  
Microbial Pollution ◽  
Limestone Aquifers

The role of propagule pressure and environmental factors on the establishment of a large invasive cyprinid: black carp in the Laurentian Great Lakes basin

2021 ◽  
pp. 1-15
Author(s):  
Eric R.B. Smyth ◽  
D. Andrew R. Drake
Keyword(s):  
Environmental Factors ◽  
Great Lakes ◽  
Environmental Conditions ◽  
Propagule Pressure ◽  
Adult Survival ◽  
Relative Role ◽  
Joint Models ◽  
Black Carp ◽  
Invasive Fishes

Understanding the factors underlying species establishment is critical for the management of invasive fishes, yet the roles of propagule pressure and environmental factors are infrequently quantified in joint models. We estimated the establishment likelihood of the invasive black carp (Mylopharyngodon piceus) by examining the relative influence of propagule pressure (introduction size and age structure) and environmental factors (temperature-driven young-of-year [YOY] overwinter survival, adult survival, age at maturity, and longevity). Simulations demonstrated that both propagule pressure and environmental factors can act as non-linear bottlenecks to establishment. When the model was applied to 12 Great Lakes tributaries and nearshore areas, black carp establishment was probable with sufficient propagules and under most environmental conditions (median p = 0.21–0.73, 0.70–1.00, and 0.46–0.97 for 100 pairs of age 4, age 9, and age 16 fish, respectively), except for YOY (p < 0.01). Our analysis is one of the few studies to examine the relative role of propagule pressure and environmental conditions on establishment, indicating that both factors can lead to establishment failure independently or concurrently within an ecosystem.

scholarly journals PROCESS-RESPONSE MODELS FOR DEPOSITIONAL SHORELINES: THE GERMAN AND THE GEORGIA BIGHTS

1978 ◽  
Vol 1 (16) ◽  
pp. 70 ◽  
Author(s):  
Dag Nummedal ◽  
Ian A. Fischer
Keyword(s):  
Simple Model ◽  
Environmental Factors ◽  
High Tide ◽  
Relative Role ◽  
Tidal Inlets ◽  
Dispersal Patterns ◽  
Response Models ◽  
High Wave ◽  
Sediment Dispersal

Sediment dispersal patterns in tidal inlets within the German and the Georgia Bights are found to be controlled by three major environmental factors: (1) the tide range, (2) the nearshore wave energy, and (3) the geometry of the backbarrier bay. Both embayments chosen for study are characterized by high wave energies and low tide ranges on their flanks, and low wave energies and high tide ranges in their centers. The spatial variability in inlet morphology, therefore, contains information on the relative role of tides and waves in inlet sediment dispersal. The paper concludes by proposing a simple model for inlet morphologies for successively greater relative role of tidal currents in the sediment dispersal.

scholarly journals Environmental factors and public health policy associated with human and rodent infection by leptospirosis: a land cover-based study in Nan province, Thailand

2015 ◽  
Vol 144 (7) ◽  
pp. 1550-1562 ◽  
Author(s):  
P. DELLA ROSSA ◽  
K. TANTRAKARNAPA ◽  
D. SUTDAN ◽  
K. KASETSINSOMBAT ◽  
J.-F. COSSON ◽  
...  
Keyword(s):  
Public Health ◽  
Land Use ◽  
Environmental Factors ◽  
Population Size ◽  
Forest Cover ◽  
Geographical Information ◽  
Health Campaigns ◽  
Sloping Ground ◽  
Public Health Campaigns

SUMMARYLeptospirosis incidence has increased markedly since 1995 in Thailand, with the eastern and northern parts being the most affected regions, particularly during flooding events. Here, we attempt to overview the evolution of human prevalence during the past decade and identify the environmental factors that correlate with the incidence of leptospirosis and the clinical incidence in humans. We used an extensive survey of Leptospira infection in rodents conducted in 2008 and 2009 and the human incidence of the disease from 2003 to 2012 in 168 villages of two districts of Nan province in Northern Thailand. Using an ad-hoc developed land-use cover implemented in a geographical information system we showed that humans and rodents were not infected in the same environment/habitat in the land-use cover. High village prevalence was observed in open habitat near rivers for the whole decade, or in 2008–2009 mostly in rice fields prone to flooding, whereas infected rodents (2008–2009) were observed in patchy habitat with high forest cover, mostly situated on sloping ground areas. We also investigated the potential effects of public health campaigns conducted after the dramatic flood event of 2006. We showed that, before 2006, human incidence in villages was explained by the population size of the village according to the environmental source of infection of this disease, while as a result of the campaigns, human incidence in villages after 2006 appeared independent of their population size. This study confirms the role of the environment and particularly land use, in the transmission of bacteria, emphasized by the effects of the provincial public health campaigns on the epidemiological pattern of incidence, and questions the role of rodents as reservoirs.

scholarly journals Sensitivity and resistance of communities: Evaluation on the example of the influence of edaphic, vegetation and spatial factors on soil macrofauna

2017 ◽  
Vol 25 (4) ◽  
Author(s):  
O. V. Zhukov ◽  
O. M. Kunah ◽  
Y. Y. Dubinina
Keyword(s):  
Environmental Factors ◽  
Species Interactions ◽  
Community Response ◽  
Ecological System ◽  
Environmental Stability ◽  
Relative Role ◽  
Soil Macrofauna ◽  
Floodplain Soil ◽  
Main Components

Environmental stability is a multifaceted concept and includes properties such as asymptotic stability, robustness, persistence, variability, elasticity and resistance. Resistance reflects the ability of a community or population to remain in a substantially unaltered state under external influence. The reverse of resistance is sensitivity. This article suggests a way to assess the sensitivity of animal communities to factors of various character and explain sensitivity and resistance of the macrofauna community near the floodplain of the river Dnieper within the "Dnipro-Orelsky" Nature Reserve to the effects of edaphic and plant factors, as well as spatial variables. It is shown that the regulatory impact of environmental factors is refracted through the properties of ecological systems themselves, namely resistance and sensitivity. If an ecological system does not react to changing environmental factors, such a system is indifferent with respect to these factors. In the case of regulatory influence of factors, there may be resistance, sensitivity and the proportionality of the response of the ecological system. The ratio of the specific role of a factor in the variability of a community to the contribution of the main components of the total variability of the attributive space makes it possible to assess the resistance, sensitivity and proportionality of response the ecological system to the action of that factor. If the ratio is >1, then this indicates sensitivity: level of variability of a community is higher than the relative role of environmental factors in the changing of the attributive space. If <1, this indicates resistance: the level of variability of a community is lower than the relative role of environmental factors in the changing of the attributive space. If the ratio =1 (≈1), changes in the community are proportional to the level of the main components of variation in comparison with other components. Ecological factors (both external environmental and internal due to species interactions and which have a neutral nature) cause different levels of community response to their impact. These differences refracted through different aspects of stability of a community can be described using the categories resistance, sensitivity and proportionality. The proposed procedure for quantification of specified properties of sustainability has established that the floodplain soil macrofauna is endowed with resistance to factors that prevail on the level of its variation. However, macrofauna is highly sensitive to minor factors. The community of the soil inhabitants is sensitive to fine-scale variations, which have a neutral nature.

Proceedings of the Biomedical Research Institute named after L. Gorky

1935 ◽  
Vol 31 (5) ◽  
pp. 670-671
Author(s):  
M. Andreev
Keyword(s):  
Environmental Factors ◽  
Biomedical Research ◽  
Twin Studies ◽  
Relative Role ◽  
Institute Of Medicine ◽  
The Third ◽  
Twin Method ◽  
Biomedical Research Institute ◽  
Research Institute

The Third Collection of Works of the Institute of Biology and Medicine (now called the Institute of Medicine and Genetics) contains 20 works; 10 of them are devoted to the study of the relative role of hereditary and environmental factors using the 'twin method' and represent a variety of twin studies.

scholarly journals Model-based study of the role of rainfall and land use–land cover in the changes in the occurrence and intensity of Niger red floods in Niamey between 1953 and 2012

2016 ◽  
Vol 20 (7) ◽  
pp. 2841-2859 ◽  
Author(s):  
Claire Casse ◽  
Marielle Gosset ◽  
Théo Vischel ◽  
Guillaume Quantin ◽  
Bachir Alkali Tanimoun
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Rainfall Variability ◽  
Drainage Area ◽  
Annual Rainfall ◽  
Data Sets ◽  
Relative Role ◽  
Land Use Land Cover ◽  
Rainfall Deficit

Abstract. Since 1950, the Niger River basin has gone through three main climatic periods: a wet period (1950–1960), an extended drought (1970–1980) and since 1990 a recent partial recovery of annual rainfall. Hydrological changes co-occur with these rainfall fluctuations. In most of the basin, the rainfall deficit caused an enhanced discharge deficit, but in the Sahelian region the runoff increased despite the rainfall deficit. Since 2000 the Sahelian part of the Niger has been hit by an increase of flood hazards during the so-called red flood period. In Niamey city, the highest river levels and the longest flooded period ever recorded occurred in 2003, 2010, 2012 and 2013, with heavy casualties and property damage. The reasons for these changes, and the relative role of climate versus land use–land cover (LULC) changes are still debated and are investigated in this paper. The evolution of the Niger red flood in Niamey from 1950 to 2012 is analysed based on long-term records of rainfall (three data sets based on in situ and/or satellite data) and discharge, and a hydrological model. The model is first run with the present LULC conditions in order to analyse solely the effect of rainfall variability. The impact of LULC and drainage area modification is investigated in a second step. The simulations based on the current surface conditions are able to reproduce the observed trend in the red flood occurrence and intensity since the 1980s. This has been verified with three independent rainfall data sets and implies that rainfall variability is the main driver for the red flood intensification observed over the last 30 years. The simulation results since 1953 have revealed that LULC and drainage area changes need to be invoked to explain the changes over a 60-year period.

scholarly journals Modeling the relative role of human mobility, land-use and climate factors on dengue outbreak emergence in Sri Lanka

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Ying Zhang ◽  
Jefferson Riera ◽  
Kayla Ostrow ◽  
Sauleh Siddiqui ◽  
Harendra de Silva ◽  
...  
Keyword(s):  
Land Use ◽  
Sri Lanka ◽  
Human Mobility ◽  
Relative Role ◽  
Climate Factors ◽  
Dengue Outbreak

Primary determinants of macrophyte community structure in 62 marshes across the Great Lakes basin: latitude, land use, and water quality effects

2001 ◽  
Vol 58 (8) ◽  
pp. 1603-1612 ◽  
Author(s):  
Vanessa L Lougheed ◽  
Barb Crosbie ◽  
Patricia Chow-Fraser
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Community Structure ◽  
Great Lakes ◽  
Aquatic Macrophyte ◽  
Potamogeton Pectinatus ◽  
Great Lakes Basin ◽  
Inland Wetlands ◽  
Macrophyte Community ◽  
Wide Range

We collected water quality, land use, and aquatic macrophyte information from 62 coastal and inland wetlands in the Great Lakes basin and found that species richness and community structure of macrophytes were a function of geographic location and water quality. For inland wetlands, the primary source of water quality degradation was inputs of nutrients and sediment associated with altered land use, whereas for coastal wetlands, water quality was also influenced by exposure and mixing with the respective Great Lakes. Wetlands within the subbasins of the less developed, more exposed upper Great Lakes had unique physical and ecological characteristics compared with the more developed, less sheltered wetlands of the lower Great Lakes and those located inland. Turbid, nutrient-rich wetlands were characterized by a fringe of emergent vegetation, with a few sparsely distributed submergent plant species. High-quality wetlands had clearer water and lower nutrient levels and contained a mix of emergent and floating-leaf taxa with a diverse and dense submergent plant community. Certain macrophyte taxa were identified as intolerant of turbid, nutrient-rich conditions (e.g., Pontederia cordata, Najas flaxilis), while others were tolerant of a wide range of conditions (e.g., Typha spp., Potamogeton pectinatus) occurring in both degraded and pristine wetlands.

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