鼎湖山马尾松林植物养分积累动态及其对人为干扰的响应  

NUTRIENT DYNAMICS IN RESPONSE TO HARVESTING PRACTICES IN A PINE FOREST OF SUBTROPICAL CHINA

作　　者：莫江明[1] 彭少麟[1] Sandra BROWN 方运霆[1] 孔国辉[1] 

机构地区：[1]中国科学院华南植物研究所鼎湖山森林生态系统定位研究站,广东肇庆526070 [2]Winrock International, 1621 N. Kent St., Suite 1200, Arlington, VA 2220 9, USA

出　　处：《植物生态学报》2004年第6期810-822,共13页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金项目 (3 0 2 70 2 83 );中国科学院知识创新工程领域前沿项目;中国科学院华南植物研究所所长基金项目;广东省自然科学基金项目 (0 2 15 2 4)

摘　　要：通过处理 (根据当地习惯收割凋落物和林下层植物 )和保护 (无任何人为干扰 )样地的比较试验 ,在 10年时间里 (1990～ 2 0 0 0年 )研究了鼎湖山生物圈保护区马尾松 (Pinusmassoniana)林群落植物养分积累动态及其对人为干扰的响应 ,在此基础上深入和较系统地分析讨论了不同的经营措施对马尾松林可持续性的影响 ,为我国目前大面积的退化马尾松林恢复和马尾松林可持续性管理提供理论依据。结果表明 :1990～ 1995年 ,5年时间里由于人为干扰活动而直接从处理样地取走的各元素养分量 ,在林下层为 (kg·hm-2 ) :132 .72 (N)、4 .72 (P)、6 3.32 (K)、2 3.5 1(Ca)和 7.0 0 (Mg) ,在地表凋落物为 (kg·hm-2 ) :4 8.93(N)、1.85 (P)、17.2 8(K)、19.2 5 (Ca)和 2 .92 (Mg)。 1990～2 0 0 0年 ,保护样地林下层和地表凋落物各元素养分贮量分别以 39%～ 4 1%和 37%～ 38%的年平均增长速率逐年提高 ,至 1995年达到高峰 ,之后各元素贮量在林下层和地表凋落物均以 14 %的年平均速率下降。在处理样地 ,1990～1995年期间各元素贮量在林下层年平均积累速率为 17% ,之后 (1995～ 2 0 0 0年期间 )则为 2 6 % ;与此同时 ,各元素贮量在地表凋落物年平均积累速率为 2 2 %～ 2 3% ,之后 (1995～ 2 0 0 0年期间 )则为 2 8%。在整个?Over the past two decades, society has become increasingly aware of pr oblems of forest degradation. The effects of forest degradation transcend indivi dual countries and now impact global processes. Research on the restoration of d egraded forests has become a key issue in global ecology. Of particular concern are the effects of human activities on forest productivity and site fertility, e specially as the demands for fuel and timber from tropical forests increase. Rem oval and burning of biomass causes nutrient losses and changes to the soil’s ph ysical and chemical characteristics. The amount of nutrient loss depends on the intensity of the activities, local environmental factors, and the type and succe ssional state of the forest. If nutrient losses cannot be recovered during regro wth, forests often become degraded through time. Thus, it is important that the nutrient dynamics of human-impacted forests are well understood in order to deve lop plans for restoration of degraded forests and for sustainable forest managem ent. Most of the primary tropical forests in southern China have been degraded by hum an activities during the past several hundred years. Factors leading to their de gradation include: timber harvesting, unsustainable agriculture, overgrazing by domestic animals, and intensive harvesting for fuel. In extreme cases, the land has become completely denuded. Attempts to reverse this process of land degradat ion have been initiated in this region of southern China. Over the last few deca des, large areas have been reforested with a native pine species, Pinus masson iana, to prevent further degradation to the landscape. Cutting of trees is now pro hibited, but harvesting of the understory and collection of litter is still allo wed to satisfy local fuel needs. Compared with whole-tree harvests, this practic e removes less biomass from the forests; however, as the understory and litter a re relatively nutrient-rich, this practice may slow or prevent the recovery of s oil fertility and produc

关 键 词：人为干扰 退化 恢复 养分动态 马尾松 鼎湖山 

分 类 号：Q948[生物学—植物学]