Abstract The substitution of biomass for fossil fuels in energy consumption is a measure to decrease the emissions of greenhouse gases and thereby mitigate global warming. During recent years, this has led to an increasing interest to use tree harvest residues as feedstock for bioenergy. An important concern related to the removal of harvesting residues is, however, the potential adverse effects on soil fertility caused by increased nutrient removal, relative to conventional stem-only harvesting. In the Netherlands this is a major concern, since most forests are located on poor sandy soils. To develop forest harvesting guidelines, we applied a mass balance approach comparing nutrient inputs by deposition and weathering with nutrient outputs by harvesting and leaching for various timber harvesting scenarios, including both stem-only harvesting and additional removal of tree tops and branches. A distinction was made in seven major tree species, six soil types (three sandy soils, loam, clay and peat soils) and nine regions, with clear variations in atmospheric deposition of phosphorus (P), calcium (Ca), magnesium (Mg) and potassium (K). For each region-tree-soil combination we calculated the maximum amounts that can be harvested such that the output of the nutrients Ca, Mg, K and P is balanced with the inputs. Results showed that at current harvesting rates, a negative balance of Ca, Mg, K or P is hardly calculated for the richer loamy to clayey soil types, while depletion can occur for the poorer sandy soils, particularly of P and K. Results are used to derive forest biomass harvesting guidelines, taking the uncertainties in the mass balance approach into account. The role of mitigating management approaches is also discussed.

中文翻译：

---

使用土壤养分平衡来制定针对荷兰地区、树种和土壤类型的森林生物量采伐指南

摘要 在能源消费中以生物质替代化石燃料是减少温室气体排放从而减缓全球变暖的一项措施。近年来，这导致人们越来越有兴趣使用树木收获残留物作为生物能源的原料。然而，与去除收获残留物有关的一个重要问题是，相对于传统的仅茎收获，养分去除增加对土壤肥力可能产生不利影响。在荷兰，这是一个主要问题，因为大多数森林都位于贫瘠的沙质土壤上。为了制定森林采伐指南，我们应用了一种质量平衡方法，将沉积和风化的养分输入与各种木材采伐情况下的采伐和浸出的养分输出进行比较，包括仅收获茎干和额外去除树梢和树枝。在七种主要树种、六种土壤类型（三种沙质土壤、壤土、粘土和泥炭土）和九个地区中进行了区分，磷（P）、钙（Ca）、镁（Mg）的大气沉降变化明显和钾（K）。对于每个区域-树木-土壤组合，我们计算了可以收获的最大数量，以便养分 Ca、Mg、K 和 P 的输出与输入平衡。结果表明，在目前的收获率下，对于较肥沃的壤土到粘质土壤类型，几乎无法计算出 Ca、Mg、K 或 P 的负平衡，而对于较贫瘠的沙质土壤，尤其是 P 和 K，可能会发生耗竭。得出森林生物量采伐指南，考虑到质量平衡方法中的不确定性。还讨论了缓解管理方法的作用。