Lovett Gary M, Ruesink Adriana E
Institute of Ecosystem Studies, Box AB, 12545, Millbrook, NY, USA.
Oecologia. 1995 Oct;104(2):133-138. doi: 10.1007/BF00328577.
Defoliation of forests by insects is often assumed to produce a pulse of available nitrogen (N) from the decomposition of frass pellets. In this study we measured rates of carbon (C) and N mineralization from gypsy moth frass incubated with and without soil, and for soil alone. Incubations were at constant temperature and soil moisture conditions and lasted for 120 days. We found that gypsy moth frass contains much labile C as well as extractable N, and that the stimulation of microbial growth by the labile C results in immobilization of essentially all of the extractable N in the frass. The response of the microbes is fast, beginning within 1 day and lasting at least 90 days. This immobilization response represents an efficient mechanism for conserving N within a forest ecosystem after a defoliation event.
昆虫对森林的落叶作用通常被认为会通过粪便颗粒的分解产生可利用氮(N)脉冲。在本研究中,我们测量了在有土壤和无土壤条件下培养的舞毒蛾粪便以及单独土壤的碳(C)和氮矿化速率。培养在恒温及土壤湿度条件下进行,持续120天。我们发现舞毒蛾粪便含有大量易分解的碳以及可提取的氮,并且易分解的碳对微生物生长的刺激导致粪便中基本上所有可提取的氮被固定。微生物的反应很快,在1天内开始并至少持续90天。这种固定反应代表了落叶事件后森林生态系统中氮的一种有效保存机制。