人为干扰对鼎湖山马尾松林土壤细根和有机质的影响(英文) |
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出 版 社:生态学报 |
发表时间:2005 |
台 站:
鼎湖山森林生态系统定位研究站
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作 者:莫江明 Sandra Brown 彭少麟 孔国辉 方运霆 |
点 击 率:6416 |
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关 键 字:人为干扰 土壤有机质 细根 分解 马尾松 南亚热带 |
摘 要:通过处理(根据当地习惯收割凋落物和林下层)和保护(无任何人为干扰)样地的比较试验,1990~1995年期间研究了人为干扰对鼎湖山生物圈保护区马尾松(Pinus massoniana)林土壤细根和有机质的影响。在此5 a的研究期间,由于人为干扰活动而直接从处理样地取走的林下层和凋落物总量为2 1.7t/ hm2。在保护样地,林下层生物量从2 .2 t/ hm2增加至11.10 t/ hm2 ,地表凋落物(包括枯死的林下层)量则从3.0 t/ hm2 增加至13.3t/ hm2 。收割林下层和凋落物这种人为干扰活动对林地土壤细根生物量的影响不明显,但却显著降低土壤轻腐殖质(Soil lightorganic matter)量。在细根分解过程中,其分解速率在处理样地(试验结束时细根残存量占起始量的4 0 .8% )显著高于在保护样地(试验结束时细根残存量占起始量的4 4 .3% ) ;与Ca、Mg和K元素不同,N和P两种元素的释放速率在处理样地显著高于保护样地,表明这种人为干扰活动不仅直接取走所收割的林下层和凋落物中的养分,而且还可能增加林地有效养分的流失潜力 |
关 键 字(英文):human-impact soil organic matter fine roots decomposition Pinus massoniana subtropical China |
摘 要(英文):Effects of human impacts on fine roots and soil organic matter of a pine forest in subtrop ical China were studied by comparing treatment (harvesting understory and litter according to practice of local people) and control (no harvest) plots in apine forest from 1990 to 1995. During this studied period, the total amount of material harvested by this practice in treatment
plots was 21.7 t/hm2. In controlplots, the standing stocks of understory increased from 2.2 to 11.1 t/hm2 at a significantly
linear pattern, while the standing stock s of litter(including dead understory) increased from 3.0 to 13.3 t/hm2. Harvesting
practice had no significant effect on the standing fine root biomass, but significantly reduced soil light organic matter in pine
forest. Mass loss in decompo sing fine roo tsw as linear in both contro land treatment plots. Fine roo ts decomposed significantly
faster in treatment (40.8 percent of init ial mass remaining at the end of the 448 day experiment ) than in control plots
(44.3% ). Nutrient losses from decomposing fine roots were significant ly faster in t reatment plots than in control plots for N
and P, but there w ere no significant difference fo r o ther elements. These t rends indicated that there could be a higher potential
fo rnut rient loss by harvesting understory and litter (more nutrients available for understory up take and litter mobilizing N Vo l. 25,No. 3
during early stage of decompo sit ion) and by leaching in treatment plots. |
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人为干扰对鼎湖山马尾松林土壤细根和有机质的影响英文.PDF |