The Dynamics of Woody Detritus in Russian Taiga Forests: A Collaborative Study

直到最近，死亡和垂死的树木在全球碳循环中的作用一直被忽视。初步估计表明，树木死亡率相当于每年4-17 X 1015克碳的大量全球流动，全球枯木储存量可能在85至295 X 1015克碳之间。这表明，一个主要的碎屑流和碳池被忽视了，这可能对平衡过去、现在和未来的全球碳预算产生重大影响。此外，需要这些信息来制定未来保护和隔离碳的战略。拟议中的项目将研究俄罗斯针叶林中木质碎屑的产生、分解、养分矿化和储存。这项工作利用了一个有60年历史的永久地块系统，它提供了一个独特的机会，可以快速增加对全球这一地区木质碎屑动态的了解。长期的树木死亡率记录将使我们能够研究木质碎屑产量如何随树木种类、放养密度和演替而变化。此外，这些记录提供了一系列自死亡以来时间变化的树木，可用于估计分解和养分矿化率。通过了解木屑的输入、分解和当前储量，我们可以估计粗木屑在演替过程中是增加、减少还是稳定。结合其他现有的样地数据（如活生物量），这些数据将使我们能够估计枯木储量和现有大规模森林调查数据的输入。拟议的项目除了为具有全球意义的森林类型提供急需的数据库外，还将有助于发展进行更广泛的区域研究所需的当地专门知识。

Until recently, the role dead and dying trees play in the global carbon cycle has been ignored. Preliminary estimates indicate tree mortality amounts to a substantial global flow of 4-17 X 1015 grams of carbon per year and that global stores of dead wood could be in the range of 85 to 295 X 1015 grams of carbon. This indicates that a major detrital flow and pool has been ignored, with potentially large consequences for balancing past, current and future global carbon budgets. Moreover, this information is required to develop strategies to conserve and sequester carbon in the future. The proposed project will study woody detritus production, decomposition, nutrient mineralization, and stores in Russian taiga forests. This work takes advantage of a 60 year-old permanent plot system which presents a unique opportunity to rapidly increase understanding of woody detrital dynamics in this part of the globe. Long-term tree mortality records will allow us to examine how woody detritus production varies with species of tree, stocking density, and succession. Moreover, these records provide a series of trees with varying time since death that can be used to estimate decomposition and nutrient mineralization rates. %%% By knowing woody detrital input, decomposition, and current stores, we will estimate whether coarse woody debris is increasing, decreasing or stable during succession. Coupled with other existing plot data (such as living biomass) this data will allow us to estimate dead wood stores and inputs from existing large-scale forest survey data. Aside from providing a much needed database for a forest type of global significance, the proposed project will help develop the local expertise needed to carry out more extensive regional studies.