ABSTRACT We examined the effects of timber harvesting and fire history on coarse woody debris (CWD) at 48 sites dispersed across the dry sclerophyll jarrah (Eucalyptus marginata) forest of south-western Western Australia. These sites represent a range of fire and harvesting histories. The mean total volume of CWD (119 ± 10 m3 ha-1), which varied greatly across the sites, was greatest on the recent harvest category (140 m3 ha−1) and least on the never harvested category (77 m3 ha−1). The ‘old harvest’ category harvested more than 40 years prior had an intermediate value (89 m3 ha−1). The increased volume of CWD on the recent harvest category consisted largely of small diameter (10–50 cm) and less decayed CWD which had been on the ground for approximately 10–60 years. Although the total volume of large CWD (diameter >50 cm) was similar across the recent, old and never harvested categories, harvesting skewed the distribution of large CWD toward the less decayed classes. Multiple linear regression was used to examine the effects of harvest intensity (amount of basal area removed), harvest history, fire history and site attributes on CWD volume. The strongest single predictors of CWD volume were the total reduction in basal area from recent and historical harvesting, and the number of prescribed fires since 1937; both positively correlated with CWD volume (r = 0.47 for both). The next strongest single predictor of the CWD volume was the number of wildfires (negatively correlated, r = −0.40). Unlike prescribed fires, wildfires reduced the accumulated volume of CWD. Over time, timber harvesting and prescribed burning increased CWD loads and reduced the volume of large diameter highly decayed CWD. Increased CWD loads resulting from past harvesting and prescribed burns are a substantial carbon store that may also benefit CWD dependent species. However, forest managers need to balance the potential benefits of maintaining large volumes of CWD against the risk that fires burning under dry summer conditions will consume a high proportion of CWD resulting in severe heating of soil and vegetation, and substantial emissions of carbon to the atmosphere.

中文翻译：

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在开阔的桉树林中，粗木屑受到历史砍伐和火灾的频率和强度的影响

摘要 我们研究了木材采伐和火灾历史对分散在西澳大利亚西南部干燥硬叶树 (Eucalyptus marginata) 森林中的 48 个地点的粗木屑 (CWD) 的影响。这些地点代表了一系列的火灾和收获历史。CWD 的平均总体积 (119 ± 10 m3 ha-1) 在不同地点差异很大，在近期收获类别 (140 m3 ha-1) 中最大，在从未收获类别 (77 m3 ha-1) 中最小）。40 多年前收获的“旧收获”类别具有中间值（89 m3 ha-1）。在最近的收获类别中增加的 CWD 体积主要包括小直径（10-50 厘米）和较少腐烂的 CWD，这些 CWD 已经在地面上存在了大约 10-60 年。尽管 CWD 的总体积较大（直径 > 50 厘米）在最近的、旧的和从未收获的类别中是相似的，收获使大 CWD 的分布偏向于较少腐烂的类别。多元线性回归用于检查采伐强度（去除的基础面积量）、采伐历史、火灾历史和场地属性对 CWD 体积的影响。CWD 数量的最强单一预测因素是最近和历史收获的基础面积总减少，以及自 1937 年以来规定的火灾数量；两者都与 CWD 体积呈正相关（两者的 r = 0.47）。CWD 体积的下一个最强的单一预测因子​​是野火的数量（负相关，r = -0.40）。与规定的火灾不同，野火减少了 CWD 的累积量。随着时间的推移，木材采伐和规定的燃烧增加了 CWD 负载并减少了大直径高度腐烂的 CWD 的体积。由于过去的收获和规定的燃烧而导致的 CWD 负荷增加是大量的碳储存，也可能有益于 CWD 依赖物种。然而，森林管理者需要权衡维持大量 CWD 的潜在好处与在干燥的夏季条件下燃烧的火灾将消耗大量 CWD 的风险，从而导致土壤和植被严重加热，并向大气排放大量碳.