Browsing by Subject "restoration"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    The feasibility of using soil seed bank for natural regeneration of degraded sandy grasslands
    (Elsevier, 2022-09) Wang, Yongcui; Chu, Lei; Liu, Zhimin; Ala, MuSa; Lin, Jixiang; Qian, Jianqiang; Zhou, Quanlai; Wang, Lixin; Earth Sciences, School of Science
    Desertification in degraded grasslands is manifested through the development of bare sandy patches, which eventually lead to habitat fragmentation. The ability of these bare sandy patches to regenerate naturally through in-situ soil seed banks is not well understood. To fill this knowledge gap, we randomly selected 24 bare sandy patches with areas ranging from 19 to 898 m2 in a desertified grassland of the Horqin sandy land, Northern China to determine whether soil seed bank can be used for natural regeneration of bare sandy patches. Species composition and density of soil seed bank as well as aboveground vegetation composition, abundance and coverage were investigated. We then determined their relationships with in-situ habitat characteristics. Our observations showed that the studied area had low soil seed bank density and species richness, as well as depauperate soil seed bank communities. Consequently, local soil seed bank was not able to provide sufficient seed source for natural regeneration. This was indicated by the relationships between aboveground vegetation, soil seed bank and the in-situ habitat characteristics. For bare patches with an area between 300 m2 and 900 m2, increase the soil seed bank density and species richness should be the main restoration measures. For bare patches with a small area of less than 50 m2, restoration of vegetation density should be the main measure. Our data highlighted that different extents of desertification, indicated by different bare patches, are requiring distinct restoration measures.
  • Thumbnail Image
    Item
    Hydrologic connectivity and land cover affect floodplain lake water quality, fish abundance, and fish diversity in floodplain lakes of the Wabash-White River basin
    (Wiley, 2022) Carlson Mazur, Martha L.; Smith, Bradley; Bird, Broxton W.; McMillan, Sara; Pyron, Mark; Hauswald, Cassie; Earth Sciences, School of Science
    Floodplain lakes are important aquatic resources for supporting ecosystem services, such as organismal habitat, biodiversity, and the retention of nutrients and sediment. Due to geomorphic alteration of river channels and land-cover change, degradation to floodplain lakes in the Ohio River basin is occurring at a rate that will escalate as climate change causes increased flood intensity and the seasonal redistribution of rainfall. A better understanding of the local drivers that affect oxbow lakes is needed for targeted floodplain restoration efforts designed to slow degradation. We examined the effects of land cover, topography, and hydrologic connectivity on water quality and fish diversity and abundance in nine floodplain lakes with potentially high remnant ecological function in the Wabash-White watershed (Indiana, Ohio, and Illinois). Data collection included water-quality parameters; stable water isotopes; total phosphorus, total nitrogen, and chlorophyll-a; and fish community diversity and abundance. Results indicate that hay/pasture land cover and decreased topographic relief in the local oxbow watersheds, along with reduced river hydrologic connectivity, were related to an increase in total phosphorus, total nitrogen, and chlorophyll-a. Greater biodiversity and abundance in fish assemblages were evident in oxbow lakes that were more disconnected from the main channel. The results of this study suggest that hydrologic connectivity of oxbow lakes with the contributing drainage area and the main channel influence nutrients and fish communities. Knowing the influencing factors can help ecosystem managers better protect these valuable floodplain lake ecosystems and prioritize restoration efforts amidst increasing stressors due to climate and land-use changes.