The effects of flooding lowland wet grassland on soil macroinvertebrate prey of breeding wading birds
The effects of flooding lowland wet grassland on soil macroinvertebrate prey of breeding wading birds
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DOI：
10.1046/j.1365-2664.2001.00600.x
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发表时间：
2001-04-01
影响因子：
5.7
通讯作者：
James, R
中科院分区：
文献类型：
--
作者：
Ausden, M;Sutherland, WJ;James, R
1.西欧的低地潮湿草地经常被用来饲养涉禽，特别是麦鸡、红脚鹬、鹬和黑尾鹬。推荐的保护管理往往需要引入冬季洪水，在英国，政府通过环境敏感区计划提供资金鼓励这种做法。大型土壤无脊椎动物是低地湿地湿地鸟类繁殖的重要猎物。本研究量化了土壤大型无脊椎动物对洪水的响应，它们在洪水淹没草地中的生存能力，以及随着洪水消退，土壤大型无脊椎动物的丰度和用于喂养涉禽的物理可用性的变化.未被淹没的草原土壤大型无脊椎动物，主要包括Tipulidae幼虫和广泛分布在牧场的物种的生物量高。冬季淹水历史较长的草地土壤大型无脊椎动物生物量较低，主要包括有限范围的半水栖物种.引入冬季洪水，以前未被淹没的草地大大减少了土壤大型无脊椎动物的生物量。这主要是由于大部分蚯蚓在洪水来临后不久就离开了土壤。然而，当蚯蚓被人工限制在淹水的土壤中时，大多数物种能够在至少120天的持续淹没中存活。冬季洪水也从土壤中驱逐了大量越冬的节肢动物。土壤大型无脊椎动物是缓慢的prononize冬季淹没草地时，它是在春季重新浸泡。因此，在前一个冬天被洪水淹没的地区，繁殖涉禽的猎物生物量仍然很低。然而，冬季的洪水可能有利于鹬的繁殖，因为它有助于保持土壤足够柔软，使它们能够探测猎物。它也可能有利于繁殖麦鸡和红脚鹬，因为它有助于保持草地的短和开放，足以让它们在繁殖季节的后期进食。春季和初夏残留的冬季洪水也为繁殖涉禽提供了水生无脊椎动物的猎物来源。我们建议，繁殖鹬的最佳饲养条件将提供保持上层土壤足够软，他们探测，但不减少土壤大型无脊椎动物生物量的洪水事先。通过创造一个由未被水淹的草地、冬季被水淹的草地和浅水池组成的马赛克，可能会为麦鸡和红脚鹬的繁殖提供最佳条件。
1. Lowland wet grassland in western Europe is often managed for breeding wading birds, especially lapwing Vanelus vanellus, redshank Tringa totanus, snipe Gallinago gallinago and black-tailed godwit Limosa limosa. Recommended conservation management often entails introducing winter flooding, and in Britain there is government funding to encourage this through the Environmentally Sensitive Area scheme.2. Soil macroinvertebrates are important prey for breeding wading birds on lowland wet grassland. This study quantified the response of soil macroinvertebrates to flooding, their ability to survive in flooded grassland, and changes in the abundance and physical availability of soil macroinvertebrates for feeding wading birds as flood water subsides.3. Unflooded grasslands contained high biomasses of soil macroinvertebrates, comprising mainly Tipulidae larvae and earthworm species that are widespread in pastures. Grasslands with a long history of winter flooding contained much lower biomasses of soil macroinvertebrates, comprising mainly a limited range of semi-aquatic earthworm species.4. Introducing winter flooding to previously unflooded grassland greatly reduced soil macroinvertebrate biomass. This was mainly due to the majority of earthworms vacating the soil soon after the onset of flooding. However, when earthworms were artificially confined in flooded soils, most species were capable of surviving periods of at least 120 days continual submergence. Winter flooding also expelled large numbers of overwintering arthropods from the soil.5. Soil macroinvertebrates were slow to recolonize winter-flooded grassland when it was re-immersed in spring. Consequently, prey biomass for breeding wading birds remained low in areas that had been flooded during the preceding winter. However, winter flooding probably benefited breeding snipe by helping keep the soil soft enough for them to probe for prey. It also probably benefited breeding lapwings and redshank by helping keep the sward short and open enough for them to feed in during the latter part of their breeding season. Pools of winter flood water that remained in spring and early summer also provided a source of aquatic invertebrate prey for breeding wading birds.6. We suggest that the best feeding conditions for breeding snipe will be provided by keeping the upper soil soft enough for them to probe in but without reducing soil macroinvertebrate biomass by flooding it beforehand. Optimal conditions for breeding lapwings and redshank will probably be provided by creating a mosaic of unflooded grassland, winter-flooded grassland and shallow pools.