Department of Plant and Wildlife Sciences, Brigham Young University, Provo, Utah, USA.
PLoS One. 2012;7(12):e52369. doi: 10.1371/journal.pone.0052369. Epub 2012 Dec 17.
Development and change in forest communities are strongly influenced by plant-soil interactions. The primary objective of this paper was to identify how forest soil characteristics vary along gradients of forest community composition in aspen-conifer forests to better understand the relationship between forest vegetation characteristics and soil processes. The study was conducted on the Fishlake National Forest, Utah, USA. Soil measurements were collected in adjacent forest stands that were characterized as aspen dominated, mixed, conifer dominated or open meadow, which includes the range of vegetation conditions that exist in seral aspen forests. Soil chemistry, moisture content, respiration, and temperature were measured. There was a consistent trend in which aspen stands demonstrated higher mean soil nutrient concentrations than mixed and conifer dominated stands and meadows. Specifically, total N, NO(3) and NH(4) were nearly two-fold higher in soil underneath aspen dominated stands. Soil moisture was significantly higher in aspen stands and meadows in early summer but converged to similar levels as those found in mixed and conifer dominated stands in late summer. Soil respiration was significantly higher in aspen stands than conifer stands or meadows throughout the summer. These results suggest that changes in disturbance regimes or climate scenarios that favor conifer expansion or loss of aspen will decrease soil resource availability, which is likely to have important feedbacks on plant community development.
森林群落的演替和变化受到植物-土壤相互作用的强烈影响。本文的主要目的是确定森林土壤特性如何随森林群落组成的梯度变化而变化，以更好地理解森林植被特征与土壤过程之间的关系。该研究在美国犹他州的 Fishlake 国家森林进行。在相邻的森林林分中采集了土壤测量数据，这些林分被描述为以白杨为主、混合、以针叶树为主或开阔草地，包括演替白杨林存在的一系列植被条件。测量了土壤化学性质、水分含量、呼吸作用和温度。有一个一致的趋势，即白杨林分的土壤养分浓度明显高于混合林分和以针叶树为主的林分以及草地。具体来说，总氮、硝酸盐和铵在以白杨为主的林分下的土壤中几乎高出两倍。初夏时，白杨林分和草地的土壤水分明显高于混合林分和以针叶树为主的林分，但到夏末，土壤水分与混合林分和以针叶树为主的林分的水平趋同。整个夏季，白杨林分的土壤呼吸作用明显高于针叶林分或草地。这些结果表明，有利于针叶树扩张或白杨损失的干扰格局或气候情景的变化将降低土壤资源的可利用性，这可能对植物群落的发展产生重要的反馈。
