11 research outputs found

    Assessing biological condition in small streams of the Puget Sound lowlands through collaborative regional monitoring

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    In 2015, the condition of Puget Sound Lowland streams was evaluated by collecting data for stream invertebrates, algae, water and sediment quality, and instream and riparian habitat. The study was designed and implemented as part of the Stormwater Action Monitoring program, a collaborative, regional stormwater monitoring program funded by more than 90 Western Washington cities and counties, the ports of Seattle and Tacoma, and the Washington State Department of Transportation. The goal of this long term program is to inform stakeholders on the status and trends of small streams within the Puget Lowlands and to track whether stream condition improves as a result of stormwater management practices in the region. A comparable number of sites were randomly selected inside and outside the Urban Growth Area (UGA). Benthic invertebrate taxa were used to calculate the benthic multi-metric index (B-IBI) and three stressor index scores for each of the 104 sites. All sites showed that sites within UGAs had poorer invertebrate condition compared to sites outside the UGA. Similar patterns were shown for algae, with the Trophic Diatom Index (TDI) indicating elevated nutrients inside the UGA compared to outside the UGA. We used boosted regression trees and a relative risk/attributable risk analysis to determine the most important human and natural factors influencing biological condition in the region. For the B-IBI, the most important factors influencing scores were December precipitation, watershed percent urban development, percent of watershed and riparian canopy cover, and stream substrate. For the TDI, the most important factors influencing condition were mean summer total phosphorus and nitrogen concentrations and watershed percent urban development. The intent is to use this status year of data to refine the sample design, and begin trend monitoring in the coming years with the goal to determine if streams are getting better or worse over time

    Applying Topographic Classification, Based on the Hydrological Process, to Design Habitat Linkages for Climate Change

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    The use of biodiversity surrogates has been discussed in the context of designing habitat linkages to support the migration of species affected by climate change. Topography has been proposed as a useful surrogate in the coarse-filter approach, as the hydrological process caused by topography such as erosion and accumulation is the basis of ecological processes. However, some studies that have designed topographic linkages as habitat linkages, so far have focused much on the shape of the topography (morphometric topographic classification) with little emphasis on the hydrological processes (generic topographic classification) to find such topographic linkages. We aimed to understand whether generic classification was valid for designing these linkages. First, we evaluated whether topographic classification is more appropriate for describing actual (coniferous and deciduous) and potential (mammals and amphibians) habitat distributions. Second, we analyzed the difference in the linkages between the morphometric and generic topographic classifications. The results showed that the generic classification represented the actual distribution of the trees, but neither the morphometric nor the generic classification could represent the potential animal distributions adequately. Our study demonstrated that the topographic classes, according to the generic classification, were arranged successively according to the flow of water, nutrients, and sediment; therefore, it would be advantageous to secure linkages with a width of 1 km or more. In addition, the edge effect would be smaller than with the morphometric classification. Accordingly, we suggest that topographic characteristics, based on the hydrological process, are required to design topographic linkages for climate change

    Mobility and bioavailability of sediment phosphorus in urban stormwater ponds

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    © 2019. American Geophysical Union. All Rights Reserved. Stormwater ponds can serve as retention hotspots for phosphorus (P) moving out of the urban environment. This retention may be reduced by P speciation that reduces the bioavailability of P to primary producers and alters its mobility in sediments. Here we examined the mobility and fate of dissolved P in urban stormwater ponds with a set of complementary field measurements and short-term laboratory and field experiments. We measured the types and amount of P in water column and sediments of urban stormwater ponds. We further assessed the mobility of different P types in pond sediments in the field and rates of P release from sediment cores maintained under laboratory conditions. Finally, we assessed P uptake rates by pond algal communities using short-term bioassay experiments. We found that dissolved organic P was highly prevalent in urban pond water and sediments and that this type of P was mobile within sediments and could be released under high or low O 2 conditions. We also found highly variable P demand by algae among stormwater ponds and that algal growth responses to P was correlated to water column N:P ratios. Altogether, our results indicate an important role for organic phosphorus cycling in urban stormwater ponds, which likely constrains the overall retention efficiency in these aquatic ecosystems

    How Nebraska’s Eastern Saline Wetland Native Plant Species Grow in Response to Restoration Methods: Application of Different Salinity Level Groundwater

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    Nebraska’s Eastern Saline Wetlands are unique ecosystems endemic to the Salt and Rock Creek waters in Lancaster and Saunders County. They provide an ecosystem services as well as habitat for endangered species such as the state endangered saltwort (Salicornia rubra) and federally endangered Salt Creek tiger beetle (Cicindela nevadica lincolniana). Over 80 % of the saline wetlands are highly degraded and in recent years, the Saline Wetland Conservation Partnership has formed to conserve and restore the remaining saline wetland fragments, but there is limited information about inland saline wetland restoration. Purpose: Investigate techniques to better conserve these saline wetlands and native saline vegetation communities through habitat restoration and plant growth and diversity. Research Question/ Objectives: How plant growth responds to saline wetland restoration techniques, specifically water application of different salinity levels and seeding time to find optimal restoration conditions Understanding how soil and water salinity effect plant germination, growth and diversity so restoration methods can be improve

    Applying Topographic Classification, Based on the Hydrological Process, to Design Habitat Linkages for Climate Change

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    The use of biodiversity surrogates has been discussed in the context of designing habitat linkages to support the migration of species affected by climate change. Topography has been proposed as a useful surrogate in the coarse-filter approach, as the hydrological process caused by topography such as erosion and accumulation is the basis of ecological processes. However, some studies that have designed topographic linkages as habitat linkages, so far have focused much on the shape of the topography (morphometric topographic classification) with little emphasis on the hydrological processes (generic topographic classification) to find such topographic linkages. We aimed to understand whether generic classification was valid for designing these linkages. First, we evaluated whether topographic classification is more appropriate for describing actual (coniferous and deciduous) and potential (mammals and amphibians) habitat distributions. Second, we analyzed the difference in the linkages between the morphometric and generic topographic classifications. The results showed that the generic classification represented the actual distribution of the trees, but neither the morphometric nor the generic classification could represent the potential animal distributions adequately. Our study demonstrated that the topographic classes, according to the generic classification, were arranged successively according to the flow of water, nutrients, and sediment; therefore, it would be advantageous to secure linkages with a width of 1 km or more. In addition, the edge effect would be smaller than with the morphometric classification. Accordingly, we suggest that topographic characteristics, based on the hydrological process, are required to design topographic linkages for climate change

    Intermediate Disturbances Enhance Microbial Enzyme Activities in Soil Ecosystems

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    The Intermediate Disturbance Hypothesis (IDH) posits that maximal plant biodiversity is attained in environments characterized by moderate ecological disturbances. Although the applicability of the IDH to microbial diversity has been explored in a limited number of studies, there is a notable absence of experimental reports on whether soil microbial ‘activity’ demonstrates a similar response to the frequency or intensity of environmental disturbances. In this investigation, we conducted five distinct experiments employing soils or wetland sediments exposed to varying intensities or frequencies of disturbances, with a specific emphasis on disturbances associated with human activity, such as chemical contamination, hydrologic changes, and forest thinning. Specifically, we examined the effects of bactericide and heavy metal contamination, long-term drainage, tidal flow, and thinning management on microbial enzyme activities in soils. Our findings revealed that microbial enzyme activities were highest at intermediate disturbance levels. Despite the diversity in experiment conditions, each trial consistently demonstrated analogous patterns, suggesting the robustness of the IDH in elucidating microbial activities alongside diversity in soils. These outcomes bear significant implications for ecological restoration and management, as intermediate disturbance may expedite organic matter decomposition and nutrient cycles, crucial for sustaining ecosystem services in soils

    Applying Topographic Classification, Based on the Hydrological Process, to Design Habitat Linkages for Climate Change

    No full text
    The use of biodiversity surrogates has been discussed in the context of designing habitat linkages to support the migration of species affected by climate change. Topography has been proposed as a useful surrogate in the coarse-filter approach, as the hydrological process caused by topography such as erosion and accumulation is the basis of ecological processes. However, some studies that have designed topographic linkages as habitat linkages, so far have focused much on the shape of the topography (morphometric topographic classification) with little emphasis on the hydrological processes (generic topographic classification) to find such topographic linkages. We aimed to understand whether generic classification was valid for designing these linkages. First, we evaluated whether topographic classification is more appropriate for describing actual (coniferous and deciduous) and potential (mammals and amphibians) habitat distributions. Second, we analyzed the difference in the linkages between the morphometric and generic topographic classifications. The results showed that the generic classification represented the actual distribution of the trees, but neither the morphometric nor the generic classification could represent the potential animal distributions adequately. Our study demonstrated that the topographic classes, according to the generic classification, were arranged successively according to the flow of water, nutrients, and sediment; therefore, it would be advantageous to secure linkages with a width of 1 km or more. In addition, the edge effect would be smaller than with the morphometric classification. Accordingly, we suggest that topographic characteristics, based on the hydrological process, are required to design topographic linkages for climate change
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