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61.
The build up of reduced inorganic sulfur in the sediments of inland wetlands and creeks is an emerging risk for the management of inland waterways and is a direct result of secondary salinisation. Inappropriate management of these sediments can lead to a number of adverse environmental outcomes, the most dramatic of which is the extreme acidification of inland waterways, but can also include deoxygenation and the release of heavy metals. This paper explores possible management options for reducing the impact of sulfidic sediments on inland waterways based on previous research into ameliorating the impact of acid mine and acid rock drainage and coastal acid sulfate soils. The main strategies explored include minimising the formation of sulfidic sediments in the first instance, rehabilitation of impacted waterways, or isolation of the water body from the surrounding environment. 相似文献
62.
Wesley M. Knapp Anne Frances Reed Noss Robert F. C. Naczi Alan Weakley George D. Gann Bruce G. Baldwin James Miller Patrick McIntyre Brent D. Mishler Gerry Moore Richard G. Olmstead Anna Strong Kathryn Kennedy Bonnie Heidel Daniel Gluesenkamp 《Conservation biology》2021,35(1):360-368
Extinction rates are expected to increase during the Anthropocene. Current extinction rates of plants and many animals remain unknown. We quantified extinctions among the vascular flora of the continental United States and Canada since European settlement. We compiled data on apparently extinct species by querying plant conservation databases, searching the literature, and vetting the resulting list with botanical experts. Because taxonomic opinion varies widely, we developed an index of taxonomic uncertainty (ITU). The ITU ranges from A to F, with A indicating unanimous taxonomic recognition and F indicating taxonomic recognition by only a single author. The ITU allowed us to rigorously evaluate extinction rates. Our data suggest that 51 species and 14 infraspecific taxa, representing 33 families and 49 genera of vascular plants, have become extinct in our study area since European settlement. Seven of these taxa exist in cultivation but are extinct in the wild. Most extinctions occurred in the west, but this outcome may reflect the timing of botanical exploration relative to settlement. Sixty-four percent of extinct plants were single-site endemics, and many occurred outside recognized biodiversity hotspots. Given the paucity of plant surveys in many areas, particularly prior to European settlement, the actual extinction rate of vascular plants is undoubtedly much higher than indicated here. 相似文献
63.
Amanda D. Hackney Robert F. Baldwin Patrick G. R. Jodice 《Journal of Coastal Conservation》2013,17(3):615-621
Barrier islands and coastal beach systems provide nesting habitat for marine and estuarine turtles. Densely settled coastal areas may subsidize nest predators. Our purpose was to inform conservation by providing a greater understanding of habitat-based risk factors for nest predation, for an estuarine turtle. We expected that habitat conditions at predated nests would differ from random locations at two spatial extents. We developed and validated an island-wide model for the distribution of predated Diamondback terrapin nests using locations of 198 predated nests collected during exhaustive searches at Fisherman Island National Wildlife Refuge, USA. We used aerial photographs to identify all areas of possible nesting habitat and searched each and surrounding environments for nests, collecting location and random-point microhabitat data. We built models for the probability of finding a predated nest using an equal number of random points and validated them with a reserve set (N?=?67). Five variables in 9 a priori models were used and the best selected model (AIC weight 0.98) reflected positive associations with sand patches near marshes and roadways. Model validation had an average capture rate of predated nests of 84.14 % (26.17–97.38 %, Q1 77.53 %, median 88.07 %, Q3 95.08 %). Microhabitat selection results suggest that nests placed at the edges of sand patches adjacent to upland shrub/forest and marsh systems are vulnerable to predation. Forests and marshes provide cover and alternative resources for predators and roadways provide access; a suggestion is to focus nest protection efforts on the edges of dunes, near dense vegetation and roads. 相似文献
64.