Relations between forest disturbance, in-stream wood and aquatic habitat over river networks

森林溪流中的河流木材或大木屑（LWD）是鱼类栖息地和覆盖物的重要贡献之一。随钻测井在井眼尺度上得到了广泛的研究。然而，在多个空间尺度上，对随钻测井的变异性及其生态功能了解甚少。Swanson（2003）认为，未来最需要的研究方向之一是从景观角度研究随钻测井在河网和时间上的生态学。人们普遍认为，森林的可持续性必须在时间和空间尺度上加以界定。研究自然干扰有助于理解时间尺度上的生态过程和模式。这对加拿大森林来说尤其重要，因为那里经常发生野火。在国家自然科学研究委员会的资助下，我的第一个五年（2002-2006）研究项目主要集中在不列颠哥伦比亚省内陆采伐和野火干扰的森林流域的LWD长期动态（时间尺度）。这项新提出的研究（2007-2011）将在多个空间尺度上针对河流网络的随钻生态学。我的具体目标包括：(1)量化随钻载荷与其在不同水流阶的生态功能之间的关系；(2)野火与采伐干扰的上述关系比较；(3)确定水网随钻量及其分布的关键控制机制。我的长期研究目标是：(1)整合随钻载荷和随钻功能在时空尺度上的信息，全面了解随钻生态；(2)将我们的结果与加拿大亚北方流域的可持续森林和流域管理联系起来。

SummaryIn-stream wood or large woody debris (LWD) in forested streams is one of most important contributions of habitat and cover for fish populations. LWD has been intensively studied at the reach scale. However, little is known about variability of LWD and its ecological functions at multiple spatial scales.  Swanson (2003) suggested that a landscape perspective on LWD ecology over river networks and through time is one of the most needed future research directions. It is widely accepted that forest sustainability must be defined in temporal and spatial scales.  Studying natural disturbance is useful for understanding ecological processes and patterns at temporal scales. This is particularly important for the Canadian forests because of frequent wildfire.   Funded by a NSERC discovery grant, my first five-year (2002-2006) research project mainly focused on LWD long-term dynamics (temporal scales) in harvested and wildfire-disturbed forest watersheds in the BC interior. This new proposed research (2007-2011) will target LWD ecology over river networks at multiple spatial scales. My specific objectives include: (1) quantification of relations between LWD loadings and their ecological functions at various stream orders; (2) comparison of the above relations between wildfire and harvesting disturbances; and (3) determination of key mechanisms controlling LWD amount and distribution over river networks.  My long-term research goals are: (1) to integrate information of LWD loadings and functions at both spatial and temporal scales to fully understand LWD ecology; and (2) to link our results with sustainable forest and watershed management in the Canadian sub-boreal watersheds.