固沙植物群落稳定性机制的探讨

采用多样性理论和冗余理论对固沙植物群落稳定性机制进行了论述。物种多样性的变化能很好地反映固沙植物群落的稳定性状态。在生物学各级水平都存在冗余, 冗余是生命系统在长期的进化过程中逐渐形成的一种特性, 其主要功能是确保生物个体和群体更好地适应极端环境、维持正常的生长发育和保持稳定, 而且其功能只是在受到干扰时才明显地表现出来。削弱冗余, 会导致在个体、种群或群落水平上产生补偿作用, 以此来增加群落的功能。固沙植物群落的稳定程度主要取决于群落内冗余的数量和结构, 冗余越多结构越复杂, 群落越稳定。削弱固沙群落的根系冗余可获得生物量上的补偿, 但使群落稳定性下降。

Discussion on Mechanism of Stability of Sand-fixing Phytocoenosium

The mechanism of sand-fixing phytocoenosium's stability was interpreted with diversity theory and redundancy theory. The degree of sand-fixing phytocoenosium's stability could be described by the change of diversity. Redundancy was one of basic characteristics of life system, which gradually formed in long time evolution process, and it existed in each level of biology. Main functions of redundancy were to assure biologic individual and colony adapting to extremely unfavorable environments more properly, to make organism growth normally and to keep stable. And only when disturbance occurred, the functions were taking effect. Reducing redundancies could lead compensation in individual, population and community. Stability of sand-fixing phytocoenosium depended on the quantity and structure of redundancy. Reducing root system redundancy could gain the compensation for aboveground biomass, but make community's stability decreased.