• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Influence of forest-clearcut edges on fungal fruiting, litter decomposition and seedling growth in low elevation second-growth conifer forests in western Washington.
【24h】

Influence of forest-clearcut edges on fungal fruiting, litter decomposition and seedling growth in low elevation second-growth conifer forests in western Washington.

机译：华盛顿西部低海拔第二生长针叶林的森林边缘对真菌结实，凋落物分解和幼苗生长的影响。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Extensive timber harvesting in the Pacific Northwest has resulted in forest landscapes that include numerous edges, where patches of older forests are bounded by more open areas. Mature second-growth Douglas-fir/western hemlock stands adjacent to very young stands resulting from recent clearcutting are particularly common at low elevations. In this study, thirteen forest interior to clearcut center transects were used to investigate soil and fungal-related edge effects on both sides of edges.; Moisture content of surface forest floor material varied more strongly with distance from edge than did moisture content of mineral soil. Moisture levels tended to be lowest just inside forest edges, and highest just outside them, for transects running through edges facing east, north or west. Soils near south-facing edges were drier than soils in clearcut centers. Forest floor moisture content was negatively correlated with soil temperature. Decomposition of Douglas-fir needles occurred more quickly on cooler, moister portions of transects. Needles in such areas were covered with more fungal hyphae and microinvertebrate debris than needles from warmer, drier plots. Regional differences in soil type appeared to be more influential than distance from edge on soil pH.; Patterns in sporocarp taxa richness and biomass production with distance from edge varied with fungal functional group and appeared to primarily reflect availability of an appropriate carbon source. Overall taxa richness of ectomycorrhizal sporocarps was high throughout forests, and declined exponentially in the first 10 m into clearcuts. Decomposer species that produced large, fleshy fruiting bodies appeared much more abundantly in clearcuts than inside forests. Despite these general patterns, individual fungal genera appeared to respond to edge conditions in unique ways. Some only fruited deep in forest interiors, while fruiting of others occurred more frequently near edges.; Results from trenched plots at edges indicated that most ectomycorrhizal fungal fruiting there required photosynthate supplied by adult trees. Western hemlock seedlings in trenched plots grew more rapidly than those in untrenched soil, which was drier, suggesting that competition with roots of adult trees might strongly influence growth of seedlings at edges of clearcuts.; These results indicate that belowground edge effects can be substantial. It seems clear that in order to understand edge effects in forest ecosystems, we need to more fully incorporate belowground organisms and the processes they mediate into edge research.
机译：西北太平洋地区大量的木材采伐导致森林景观包括许多边缘，在这些森林中，较旧的森林被更多开放区域所包围。成熟的次生花旗松/西部铁杉林与最近伐木形成的非常年轻的林木相邻，在低海拔地区尤为常见。在这项研究中，从13个森林内部到明确的中央样点被用来调查土壤和真菌相关的边缘两侧的边缘效应。森林地表地面材料的水分含量随距边缘的距离变化比矿物土壤的水分含量变化更大。对于横贯东部，北部或西部边缘的样带，水分水平仅在森林边缘内部最低，而在森林外部最高。朝南边缘附近的土壤比明确中心的土壤干燥。林地水分含量与土壤温度呈负相关。花旗松针的分解发生在较凉爽，较潮湿的样带部分上。与来自较温暖干燥地区的针头相比，这些区域的针头上覆盖着更多的真菌菌丝和微无脊椎动物碎片。土壤类型的区域差异似乎比土壤边缘距土壤pH值的影响更大。孢子类群丰富度和生物量生产的模式随边缘距离的变化随真菌官能团的变化而变化，并且似乎主要反映了适当碳源的可用性。整个森林中，外生菌根子果皮的总体类群丰富度很高，在开阔地带的头10 m内呈指数下降。产生较大的肉质子实体的分解物种类在纯净地带中比在森林内部更为丰富。尽管有这些一般模式，但单个真菌属似乎以独特的方式对边缘条件作出反应。一些只在森林内部深处结实，而另一些则在边缘附近更常发生。边缘沟槽图的结果表明，大多数外生菌根真菌在那里需要成年树提供的光合产物。开沟地块中的西部铁杉幼苗比未打soil的土壤中的干燥更快，后者更干燥，这表明与成年树根的竞争可能会强烈影响清晰边缘的幼苗生长。这些结果表明地下边缘效应可能是巨大的。显然，为了了解森林生态系统的边缘效应，我们需要更充分地将地下生物及其介导的过程纳入边缘研究。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号