scholarly journals Relationships between Riparian Forest Fragmentation and Biological Indicators of Streams

2019 ◽  
Vol 11 (10) ◽  
pp. 2870 ◽  
Author(s):  
Yirigui Yirigui ◽  
Sang-Woo Lee ◽  
A. Pouyan Nejadhashemi ◽  
Matthew R. Herman ◽  
Jong-Won Lee
Keyword(s):  
Forest Fragmentation ◽  
Forest Cover ◽  
Riparian Forest ◽  
Anthropogenic Activities ◽  
Sampling Site ◽  
Monitoring Program ◽  
Regression Tree ◽  
Biological Indicators ◽  
Riparian Forests ◽  
Biological Assessment

Anthropogenic activities, such as land use and land cover modifications in riparian areas, can alter the degree of fragmentation of riparian vegetation, lead to the degradation of stream habitats, and affect biological communities in the streams. The characteristics of the riparian forests can modify the condition of stream environments and the transporting mechanisms of materials, sediments, nutrients, and pollutants loaded from the watersheds. This study aimed to examine the relationships between forest fragmentation and three biological indicators of trophic diatom, benthic macroinvertebrate, and the fish assessment in the Nakdong River, Korea. Eighty-nine biological assessment sampling sites in the National Aquatic Ecological Monitoring Program of South Korea were identified. For each sampling site, riparian forest data within a 500 m radius were extracted from national LULC using GIS to compute fragmentation metrics using FRAGSTATS software. Four fragmentation metrics—number of forest patches, percentage of riparian forest cover (PLAND), largest riparian forest patch index (LPI), and riparian forest division index (DIVISION)—were correlated with the biological indicators. Also, due to severe spatial autocorrelation among observations, the fragmentation metrics and stream environmental variables were regressed to biological indicators using regression tree analysis. Our results indicate that the biological indicators were significantly associated with most forest fragmentation metrics. We found positive correlations of PLAND and LPI with biological indicators, whereas DIVISION was negatively correlated with biological indicators. Both correlation and regression tree analyses revealed that the biological conditions of streams were likely to be better if riparian forests are less fragmented. Particularly, stronger relationships were revealed between macroinvertebrates and fish with the fragmentation metrics of riparian forests than with benthic diatoms. However, these relationships varied with elevation, stream size, and slope conditions. The results of this study reinforced the importance of including riparian forests in the planning, restoration, and management of stream environments. These results also suggested that planners and managers may need to consider different strategies for different stream environments and topographic characteristics in managing riparian forests.

scholarly journals Multi-Scale Assessment of Relationships between Fragmentation of Riparian Forests and Biological Conditions in Streams

2019 ◽  
Vol 11 (18) ◽  
pp. 5060 ◽  
Author(s):  
Yirigui ◽  
Lee ◽  
Nejadhashemi
Keyword(s):  
Water Quality ◽  
Forest Fragmentation ◽  
Ecosystem Health ◽  
Riparian Forest ◽  
Anthropogenic Activities ◽  
Biological Indicators ◽  
Riparian Forests ◽  
Riparian Areas ◽  
Forest Patches ◽  
Biological Condition

Due to anthropogenic activities within watersheds and riparian areas, stream water quality and ecological communities have been significantly affected by degradation of watershed and stream environments. One critical indicator of anthropogenic activities within watersheds and riparian areas is forest fragmentation, which has been directly linked to poor water quality and ecosystem health in streams. However, the true nature of the relationship between forest fragmentation and stream ecosystem health has not been fully elucidated due to its complex underlying mechanism. The purpose of this study was to examine the relationships of riparian fragmented forest with biological indicators including diatoms, macroinvertebrates, and fish. In addition, we investigated variations in these relationships over multiple riparian scales. Fragmentation metrics, including the number of forest patches (NP), proportion of riparian forest (PLAND), largest riparian forest patch ratio (LPI), and spatial proximity of riparian forest patches (DIVISION), were used to quantify the degree of fragmentation of riparian forests, and the trophic diatom index (TDI), benthic macroinvertebrates index (BMI), and fish assessment index (FAI) were used to represent the biological condition of diatoms, macroinvertebrates, and fish in streams. PLAND and LPI showed positive relationships with TDI, BMI, and FAI, whereas NP and DIVISION were negatively associated with biological indicators at multiple scales. Biological conditions in streams were clearly better when riparian forests were less fragmented. The relationships of NP and PLAND with biological indicators were stronger at a larger riparian scale, whereas relationships of LPI and DIVISION with biological indicators were weaker at a large scale. These results suggest that a much larger spatial range of riparian forests should be considered in forest management and restoration to enhance the biological condition of streams.

scholarly journals The Importance of Riparian Forest Cover to the Ecological Status of Agricultural Streams in a Nationwide Assessment

2021 ◽  
Author(s):  
Mikko Tolkkinen ◽  
Saku Vaarala ◽  
Jukka Aroviita
Keyword(s):  
Land Use ◽  
Forest Cover ◽  
Riparian Forest ◽  
Ecological Status ◽  
Freshwater Ecosystems ◽  
Agricultural Landscapes ◽  
Riparian Forests ◽  
Independent Effect ◽  
Medium Size ◽  
Positive Effect

AbstractForested riparian corridors are a key management solution for halting the global trend of declining ecological status of freshwater ecosystems. There is an increasing body of evidence related to the efficacy of these corridors at the local scale, but knowledge is inadequate concerning the effectiveness of riparian forests in terms of protecting streams from harmful impacts across larger scales. In this study, nationwide assessment results comprising more than 900 river water bodies in Finland were used to examine the importance of adjacent land use to river ecological status estimates. Random forest models and partial dependence functions were used to quantify the independent effect of adjacent land use on river ecological status after accounting for the effects of other factors. The proportion of adjacent forested land along a river had the strongest independent positive effect on ecological status for small to medium size rivers that were in agricultural landscapes. Ecological quality increased by almost one status class when the adjacent forest cover increased from 10 to 60%. In contrast, for large rivers, adjacent forested land did not show an independent positive effect on ecological status. This study has major implications for managing river basins to achieve the EU Water Framework Directive (WFD) goal of obtaining good ecological status of rivers. The results from the nationwide assessment demonstrate that forested riparian zones can have an independent positive effect on the ecological status of rivers, indicating the importance of riparian forests in mitigating the impacts of catchment-level stressors. Therefore, forested buffer zones should be more strongly considered as part of river basin management.

scholarly journals Water-use dynamics of an alien-invaded riparian forest within the Mediterranean climate zone of the Western Cape, South Africa

2017 ◽  
Vol 21 (9) ◽  
pp. 4551-4562 ◽  
Author(s):  
Bruce C. Scott-Shaw ◽  
Colin S. Everson ◽  
Alistair D. Clulow
Keyword(s):  
South Africa ◽  
Water Use ◽  
Sap Flow ◽  
Riparian Forest ◽  
Riparian Forests ◽  
Ratio Method ◽  
Natural State ◽  
Indigenous Species ◽  
Western Cape ◽  
Selection Of

Abstract. In South Africa, the invasion of riparian forests by alien trees has the potential to affect the country's limited water resources. Tree water-use measurements have therefore become an important component of recent hydrological studies. It is difficult for South African government initiatives, such as the Working for Water (WfW) alien clearing program, to justify alien tree removal and implement rehabilitation unless hydrological benefits are known. Consequently, water use within a riparian forest along the Buffeljags River in the Western Cape of South Africa was monitored over a 3-year period. The site consisted of an indigenous stand of Western Cape afrotemperate forest adjacent to a large stand of introduced Acacia mearnsii. The heat ratio method of the heat pulse velocity sap flow technique was used to measure the sap flow of a selection of indigenous species in the indigenous stand, a selection of A. mearnsii trees in the alien stand and two clusters of indigenous species within the alien stand. The indigenous trees in the alien stand at Buffeljags River showed significant intraspecific differences in the daily sap flow rates varying from 15 to 32 L day−1 in summer (sap flow being directly proportional to tree size). In winter (June), this was reduced to only 7 L day−1 when limited energy was available to drive the transpiration process. The water use in the A. mearnsii trees showed peaks in transpiration during the months of March 2012, September 2012 and February 2013. These periods had high average temperatures, rainfall and high daily vapor pressure deficits (VPDs – average of 1.26 kPa). The average daily sap flow ranged from 25 to 35 L in summer and approximately 10 L in the winter. The combined accumulated daily sap flow per year for the three Vepris lanceolata and three A. mearnsii trees was 5700 and 9200 L, respectively, clearly demonstrating the higher water use of the introduced Acacia trees during the winter months. After spatially upscaling the findings, it was concluded that, annually, the alien stand used nearly 6 times more water per unit area than the indigenous stand (585 mm a−1 compared to 101 mm a−1). This finding indicates that there would be a gain in groundwater recharge and/or streamflow if the alien species are removed from riparian forests and rehabilitated back to their natural state.

Relationship between Morphology and Trophic Ecology in an Assemblage of Passerine Birds in Riparian Forests of the Paraná River (Argentina)

2018 ◽  
Vol 11 (1) ◽  
pp. 44-53 ◽  
Author(s):  
Virginia Quiroga ◽  
Rodrigo E. Lorenzón ◽  
Gisela Maglier ◽  
Ana L. Ronchi-Virgolini
Keyword(s):  
Trophic Ecology ◽  
Riparian Forest ◽  
A Priori ◽  
Bird Species ◽  
Morphological Characteristics ◽  
Paraná River ◽  
Riparian Forests ◽  
Phylogenetic Constraint ◽  
Parana River ◽  
Coexisting Species

We describe the ecomorphology of an assemblage of bird species found in riparian forests of the Middle Paraná River, Argentina. We sought to determine (1) the more important morphological characteristics that separate coexisting species, (2) whether such separation was related to the trophic ecology of each species and (3) whether a priori guilds showed morphological similarity. We tested the hypotheses that (a) a species’ morphology is related to the trophic ecology of that species and (b) that species of a priori guilds are morphometrically more similar to each other than to species of different a priori guilds. For this, we considered an assemblage of 29 species of birds from riparian forest that were sampled with mist nets during the 2011 and 2014 breeding seasons. We obtained morphometric measurements of captured individuals and supplemented those data with measurements from museum specimens. Trophic characterisation (diet and trophic microhabitat) was based on a literature review. Results showed a separation of bird species as a function of variables related to trophic ecology (diets and trophic microhabitats) and morphology. After controlling for phylogenetic constraint, species’ morphology partially reflected the trophic ecology of the species, supporting the central hypothesis of the ecomorphological discipline and showing that the use of trophic and morphometric data provides complementary data to improve the guild organisation of riparian bird assemblages.

scholarly journals Análise comparativa da fragilidade ambiental da bacia do rio Piracicaba a partir da aplicação de dois modelos metodológicos: suporte para o estabelecimento e proposição de Corredores Ecológicos.

2020 ◽  
Vol 13 (6) ◽  
pp. 3060
Author(s):  
Suelen Crispim Sutil ◽  
José Augusto Costa Gonçalves ◽  
Eliane Maria Vieira
Keyword(s):  
Environmental Management ◽  
Comparative Analysis ◽  
River Basin ◽  
Forest Fragmentation ◽  
Riparian Forests ◽  
Forest Patches ◽  
Biological Corridors ◽  
Gradual Development ◽  
History Of ◽  
Piracicaba River

A avaliação da fragilidade ambiental das bacias hidrográficas vem se tornando cada vez mais importante no cenário ambiental, devido ao desenvolvimento gradativo da sociedade e a expansão tecnológica e econômica ao longo dos anos. Uma estratégia adotada para amenizar a degradação e restabelecer o equilíbrio, é a formação de corredores ecológicos (CEs), que auxilia na ligação entre remanescentes naturais. A bacia do rio Piracicaba passa por um longo histórico de degradação e de fragmentação florestal, principalmente próximo às cidades devido ao desmatamento de matas ciliares. Em vista disso, este trabalho analisou e comparou a aplicação de dois diferentes modelos de fragilidade ambiental, aplicada a esta bacia e, a partir de seus produtos identificou a melhor metodologia base para a proposição de corredores ecológicos na região. Com os resultados obtidos, foi possível inferir que, além de grande parte da bacia apresentar grau de fragilidade entre fraco e médio, as áreas mais vulneráveis são aquelas mais próximas à cabeceira da bacia. O estabelecimento dos corredores ecológicos abrangeu, prioritariamente, as áreas de maior fragilidade entre a conexão dos fragmentos de vegetação e as Áreas de Preservação Permanentes (APPs), assim, verificou-se que é necessário o reflorestamento de cerca de 342,24 km² das APPs da bacia para que seja possível a conexão entre as remanescentes e 2,0 km²  de áreas de ligação. Comparative analysis of the environmental fragility of the Piracicaba river basin using two methodological models: support for the application and proposition of Biological Corridors A B S T R A C TThe assessment of a river basin’s environmental fragility has become even more important on the environmental scenery due to society’s gradual development and technological and economic expansion over the years. An adopted strategy to ease the degradation and restore the ecological balance is the establishment of biological corridors that can assist the connection between natural forest patches. The Piracicaba river basin has been going through a long history of degradation and forest fragmentation, especially near the cities because of the deforestation of riparian forests. Therefore, this paper analyzed and compared the application of two adapted environmental fragility models in this river basin and identified from their products the best base methodology for the proposition of ecological corridors. From the results, it was possible to infer that, in addition to a big part of the basin present poor and average fragility level, the most vulnerable areas are the ones close to the source of the main rivers. The biological corridors establishment covered, primarily, the most vulnerable areas between the fragments of remaining forests and the Permanent Preservation Areas (PPAs) and, from this, it was possible to verify that the reforestation of around 132,14 mi² of PPAs is necessary for the connection of patches of remaining forests and 0,77 mi² of connections areas.Keywords: environmental vulnerability, geoprocessing, environmental management.

scholarly journals Land-use-driven stream warming in southeastern Amazonia

2013 ◽  
Vol 368 (1619) ◽  
pp. 20120153 ◽  
Author(s):  
Marcia N. Macedo ◽  
Michael T. Coe ◽  
Ruth DeFries ◽  
Maria Uriarte ◽  
Paulo M. Brando ◽  
...  
Keyword(s):  
Land Use ◽  
Crop Production ◽  
Large Scale ◽  
Management Practices ◽  
Forest Cover ◽  
Riparian Forest ◽  
Soya Bean ◽  
Nutrient Inputs ◽  
Mato Grosso ◽  
Small Streams

Large-scale cattle and crop production are the primary drivers of deforestation in the Amazon today. Such land-use changes can degrade stream ecosystems by reducing connectivity, changing light and nutrient inputs, and altering the quantity and quality of streamwater. This study integrates field data from 12 catchments with satellite-derived information for the 176 000 km 2 upper Xingu watershed (Mato Grosso, Brazil). We quantify recent land-use transitions and evaluate the influence of land management on streamwater temperature, an important determinant of habitat quality in small streams. By 2010, over 40 per cent of catchments outside protected areas were dominated (greater than 60% of area) by agriculture, with an estimated 10 000 impoundments in the upper Xingu. Streams in pasture and soya bean watersheds were significantly warmer than those in forested watersheds, with average daily maxima over 4°C higher in pasture and 3°C higher in soya bean. The upstream density of impoundments and riparian forest cover accounted for 43 per cent of the variation in temperature. Scaling up, our model suggests that management practices associated with recent agricultural expansion may have already increased headwater stream temperatures across the Xingu. Although increased temperatures could negatively impact stream biota, conserving or restoring riparian buffers could reduce predicted warming by as much as fivefold.

Landscape fragmentation

2010 ◽  
Author(s):  
Ned Horning ◽  
Julie A. Robinson ◽  
Eleanor J. Sterling ◽  
Woody Turner ◽  
Sacha Spector
Keyword(s):  
Forest Fragmentation ◽  
Landscape Metrics ◽  
Forest Cover ◽  
Remotely Sensed ◽  
Clear Understanding ◽  
Remotely Sensed Data ◽  
Deforestation Rates ◽  
Habitat Conversion ◽  
Conservation Organizations ◽  
Total Core Area

The country of Vietnam has long been recognized as an important region for biodiversity (Sterling et al. 2006). High-profile discoveries in the 1990s of many species new to science including large ones such as the Saola (Pseudoryx nghetinhensis), an 85 kg basal member of the cattle subfamily Bovinae and the first new genus of large land-dwelling mammal described since the okapi (Okapia johnstoni) in 1901, have focused the attention of national and international conservation organizations on Vietnam and surrounding countries in mainland Southeast Asia (Hurley et al. in prep.). Conservation action for these endemic, endangered species relies on a clear understanding of trends in habitat conversion. To track deforestation rates through time in Vietnam, Meyfroidt and Lambin (2008) combined remotely sensed data with landscape metrics such as number of patches, mean patch size, mean proximity index, and total core area index. They tested their analyses across a variety of land cover studies including those using Advanced Very High Resolution Radiometer (AVHRR), Landsat, SPOT, and MODIS data sources. They found that forest cover decreased nationally from the 1980s to the 1990s and then showed an increase between 1990 and 2000, due to plantation forests as well as natural forest regeneration. However, the effects of this forest transition on fragmentation metrics noted above differed across the country. For instance, in some places, such as central Vietnam where forest cover is relatively large and well connected, reforestation led to a decrease in forest fragmentation and secondary forests recovered rapidly. However in others, such as areas in the north where forest fragmentation dates back centuries and forests have therefore long been isolated, reforestation did not seem to have an impact on continued fragmentation and habitat loss. In this chapter we detail the importance of fragmentation and landscape metrics to ecology and conservation, outlining when and where remotely sensed data can help in these analyses. We then discuss a subset of fragmentation metrics and point to some challenges in processing fragmentation data. We provide examples of composition and connectivity metrics illuminated with examples from the remote sensing literature.

scholarly journals Assessment of the Incidence of Enteric Adenovirus Species and Serotypes in Surface Waters in the Eastern Cape Province of South Africa: Tyume River as a Case Study

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Timothy Sibanda ◽  
Anthony I. Okoh
Keyword(s):  
Surface Waters ◽  
Anthropogenic Activities ◽  
Sampling Site ◽  
Eastern Cape ◽  
Conventional Pcr ◽  
Treated Sewage ◽  
Sampling Points ◽  
Enteric Adenovirus ◽  
Treatment Facilities

TaqMan real-time PCR was used for the detection and quantitation of adenoviruses in Tyume River water samples over a 12-month period. A total of 72 samples were analysed, and 22 samples were positive for adenovirus. Of the positive samples, 18 were collected from downstream sampling points. Among the downstream sampling points, adenovirus detection rate increased with distance downstream, being 28%, 33%, and 39% for Alice, Drayini, and Manqulweni, respectively. The Alice sampling site had the highest concentrations of adenovirus ranging between6.54×103 genome copies/L and8.49×104 genome copies/L. The observed trend could have been expected considering the level of anthropogenic activities in areas along the lower stretch of Tyume River, with the major one being the effluent of treated and semi treated sewage from wastewater treatment facilities. Adenovirus detection was sporadic at most sampling sites. Multiplex conventional PCR was used for the detection of clinically important adenovirus species B, C, and F and their serotypes. Species C and F adenoviruses were detected in 77% and 18% of the samples, respectively. Most adenovirus positive samples were obtained from areas of increased population densities. The presence of adenoviruses may confirm the risk of its transmission to the human population.

scholarly journals Spatial variability of ammonium, nitrite and nitrate concentrations in water of Batang Arau River, West Sumatera, Indonesia

2020 ◽  
Vol 20 (4) ◽  
pp. 1484-1492
Author(s):  
Denny Helard ◽  
Shinta Indah ◽  
Michella Oktavia
Keyword(s):  
Spatial Variability ◽  
Anthropogenic Activities ◽  
Nitrogen Concentration ◽  
Monitoring Program ◽  
Quality Standard ◽  
Nitrite Concentration ◽  
Sampling Locations ◽  
Maximum Permissible Concentrations ◽  
Nitrate Concentrations ◽  
Nitrogen Concentrations

Abstract The objective of this study is to analyze the spatial variability of ammonia, nitrite, and nitrate concentrations along the Batang Arau River, one of the most important rivers in West Sumatera, Indonesia. The results showed that the ammonium, nitrite, and nitrate concentrations were in the range of 0.180–0.510 mg/L, 0.0–0.178 mg/L, and 0.675–1.165 mg/L, respectively. The ammonium and nitrate concentrations were still below the maximum permissible concentrations for the river water quality standard of class II established by the Regulation Governor of West Sumatera at all of the sampling locations, except at midstream for ammonium, while the nitrite concentration had exceeded the quality standard from midstream to downstream of the river. The increase of the nitrogen concentration was observed from upstream to downstream of the river. Spatial analysis shows significant differences in nitrogen concentrations were obtained between the upstream and the midstream of the Batang Arau River (p < 0.05) but were not observed between the midstream and the downstream. This indicates the effect of different anthropogenic activities along the river. Based on the obtained results, for an effective monitoring program of the nitrogen concentration along the Batang Arau River, reducing the sampling locations from eight to five could be implemented.

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