首页|刈割扰动下半干旱区豆科牧草种间关系的反应

刈割扰动下半干旱区豆科牧草种间关系的反应

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  • 国家科技期刊平台
  • NETL
  • NSTL
  • 万方数据
  • 维普
以苜蓿和沙打旺根据生物替代设计组成的简单混播种群为对象,通过调查2种牧草在刈割扰动下的生长反应,比较了单混播处理条件下3种播种密度刈割处理的种间关系和补偿性反应特点,探讨了种群稳定与演替的可能机制.结果表明苜蓿和沙打旺在刈割条件下,土壤水分利用竞争空间上移 20 cm,并且水分利用呈增加趋势,土壤平均水分为15%.刈割诱导低密度混播处理和高密度苜蓿单播处理土壤水分最高,分别达15.6%和15.8%.单播下,刈割可诱导中高密度单播沙打旺处理产量分别增加33%和29%,而混播方式下,刈割均导致沙打旺和苜蓿株高、分枝数和地上部生物量小于对照.在刈割干扰下,相比对照,苜蓿与沙打旺两者仍然为资源共享关系,但互利共生程度下降了21%,而混播种群中苜蓿对沙打旺的相对竞争力增加了17%.不论单播还是混播,刈割均可引发2种牧草显著的补偿机制.同时发现刈割干扰可激发更强的自疏作用.2种牧草的生长指标呈下降趋势可能是干旱、刈割和种间竞争或化感协同胁迫作用的结果,但共存与补偿机制有利于减缓这种负面效应.沙打旺和苜蓿的更新补偿时间上的异质性,实现资源利用生态位的分离,从而调控着2种牧草组成的种群稳定性,这对理解生物多样性维持机制具有重要的参考意义.
Response to cutting treatment of interspecific relationships of leguminous forages in semiarid regions
The growth response of simple and artifical communities of Astragalus adsurgens and Medicago sati-va to cutting treatments based on a biological replacement method was investigated. A relative study of interspecific relationships and compensative effects of both leguminous forages was done at three sowing densities for monoculture and mixtures and compared with cutting grass. The possible mechanisms for communities maintaining stable and successive status is discussed. Compared with the control, the cutting treatment led to a competitively spatial increase of about 20 cm in soil water utilization by A. adsurgens and M. sativa. This in-ducible effect increased soil moisture absorption by about 15%. In particular, the cutting treatment significantly enhanced water use of mixtures by 15. 6% in low density sowings and by 33% for monocultures of M. sativa in high density sowings. In addition, cutting treatment induced an aerial biomass increase of 29% in A. adsurgens monoculture in the middle and high density sowings. However, plant height, branch numbers per plant, and aboveground biomass declined under the cutting treatment compared with the control. A. adsurgens and M. sativa showed weak resources-sharing with a decline of nearly 21% if artificially regulated by cutting and the relative competition of M. sativa to A. adsurgens was increased by 17%. Whether in monoculture or in a mixture, cutting would increase the compensatory effect of both forages. It was also found that cutting caused drastic density-limiting effects. The low productivity from additional cutting resulted from the synergistic effect of pressures such as arid circumstances, interspecific competition and allelopathic potential, which can be alleviated by coexistence and compensation. In the present study, the growth response and interspecific relationship resulting from cutting can indicate some potent mechanisms for maintaining the biodiversity of communities and the sustainable development of the forage industry.

interspecific relationshipcutting interferenceleguminous foragesdensity-dependent mortalitycompensation heterogeneitybiodiversity maintenance

左胜鹏、王会梅、马永清、李凤民、山仑

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安徽师范大学环境科学学院,安徽,芜湖,241000

中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西,杨凌,712100

种间关系 刈割扰动 豆科牧草 自疏作用 补偿异质性 生物多样性

中国科学院百人计划择优支持项目国家自然科学基金安徽高等学校省级自然科学研究项目安徽师范大学校青年基金黄土高原土壤侵蚀与旱地农业国家重点实验室主任基金

C2401620030870403KJ2008B1922008xqn7510501-242

2009

草业学报
中国草原学会 兰州大学草地农业科技学院

草业学报

CSTPCDCSCD北大核心
影响因子：4.082
ISSN：1004-5759
年,卷(期)：2009.18(5)
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