Soil respiration following Chinese fir plantation clear-cut: Comparison of two forest regeneration approaches
Soil respiration following Chinese fir plantation clear-cut: Comparison of two forest regeneration approaches
复制标题
杉木人工林砍伐后土壤呼吸：两种森林更新方法的比较
DOI：
10.1016/j.scitotenv.2019.135980
复制
发表时间：
2020
影响因子：
9.8
通讯作者：
Frank Berninger
中科院分区：
文献类型：
--
作者：
Shangbin Bai;Wanting Qiu;Hui Zhang;Yixiang Wang;Frank Berninger
针对长期纯针叶人工林造成的生态问题，提出了清伐、物种混合等森林更新措施，以发展针叶林与阔叶林混交林。然而，这些森林更新方式对土壤呼吸的动态影响尚未得到很好的研究。本研究以中国亚热带杉木纯人工林为研究对象，比较了两种完全不同的森林更新方式连续3年的土壤呼吸变化。这两种方法分别是：1、第一年地面植被切割和去除斜线，第二年地面植被切割并保留在场地上；2、第一年地面植被切割和斜线燃烧，第二年土壤翻耕，补种，地面植被切割但保留在场地上。两个更新地的土壤呼吸变化明显。方法1和方法2第1年的平均呼吸速率低于未砍伐对照（- 15.0%和- 26.8%），表明土壤呼吸随着地面植被的清除或砍伐后的刀削林燃烧而降低。与第1年相比，方法1和方法2处理的平均呼吸速率均高于未刈割对照（第二年+12.8%和+32.2%，第三年16.3%和30.8%），表明刈割残留地面植被或土壤翻耕显著增加了土壤呼吸。这种剧烈变化主要是由于林下植被和新苗的快速生长、物种组成的差异、呼吸有机质的有效性以及两种更新方式不同的具体森林实践引起的土壤扰动强度随时间的变化。此外，不同的物种混合和森林管理做法增加了与土壤呼吸分析有关的不确定性。研究结果表明，高强度森林更新方式具有较高的土壤co2排放和较低的生物量产量。森林更新方式可以降低土壤呼吸的温度敏感性。我们的研究结果为森林实践对砍伐后土壤co2通量的影响提供了新的见解。
In response to ecological problems originating from long-term pure coniferous plantations, clear-cut, species mixing, and other forest regeneration practices have been proposed to develop into mixed conifer-broadleaved stand. However, the dynamic effects of these forest regeneration approaches on soil respiration have not been well investigated. In this study, we compared soil respiration for three continuous years from two completely different forest regeneration approaches in clear-cut areas with uncut as control in pure Chinese fir plantations in subtropical China. These two approaches were, I: ground vegetation cut and removal of slash in the first year followed by the second year's ground vegetation cut but retained on the site, and II: ground vegetation cut and slash burning in first year followed by second year's soil ploughing, replanting, ground vegetation cut but retained on the site. Soil respiration changed obviously as forest practices were applied in the both regeneration sites. Mean respiration rate for the first year was lower for the treatments of Approach I and Approach II than uncut control (−15.0% and −26.8%), indicating that soil respiration decreased with ground vegetation removal or slash burning after clear-cut. In contrast to the first year, mean respiration rate was higher for the treatments of Approach I and Approach II treatments than uncut control (+12.8% and +32.2% in the second year, 16.3% and 30.8% in the third year), indicating ground vegetation cut with retaining residuals or soil ploughing significantly increased soil respiration. These drastically changes were mainly due to the rapid growth of understory vegetation and new seedlings, the difference of species composition, the availability of respired organic matter and the intensity of soil disturbance induced by different specific forest practices of two regeneration approaches over time. In addition, the different species mixing and forest management practices enhance the uncertainty linked to the analyses of soil respiration. Our results suggest that high intensity forest regeneration approach has a higher soil CO2emission and lower production of biomass. Forest regeneration approaches could decrease the temperature sensitivity of soil respiration. Our findings provide new insights into the effects of forest practices on soil CO2flux following clear-cut.