CAJ | 학술논문

基于17 yr的野外实验数据,研究了内蒙古羊草草原群落刈割演替过程中的功能群组成动态,探索了功能群组成变化与群落净初级生产力(ANPP)之间的关系,分析了结构参数怎样影响功能参数.结果显示:在17 yr的割草演替过程中,群落的结构与功能均发生了变化.随着羊草群落刈割演替的进行,群落的功能群组成发生了显著变化,根茎禾草在群落中的优势地位相继被一、二年生植物、高丛生禾草和矮丛生禾草所取代.到17 yr末,群落变成根茎禾草、矮丛生禾草、高丛生禾草共同建群的群落.在对照群落中ANPP与年降水量显著相关,但在刈割群落中二者则不相关.年降水量解释对照群落ANPP变异的62%,而连年的刈割干扰则是刈割群落中ANPP动态的主要驱动因子.群落净初级生产则显出对刈割干扰的抵抗能力,在刈割干扰的前几年,依靠群落内功能群组成的不断调节,保持相对稳定的水平,当刈割进行5 yr之后,群落结构的变化积累到一定程度,净初级生产迅速下降到一个较低的水平,此后依靠群落结构的不断调节来维持这一功能水平.因此,群落结构是以渐变的方式改变的,而群落功能的下降则是以跃变的形式完成的.群落依赖于结构的不断调整来保持功能的相对稳定,但结构变化到一定程度也会导致功能的衰退.
기우17 yr적야외실험수거,연구료내몽고양초초원군락예할연체과정중적공능군조성동태,탐색료공능군조성변화여군락정초급생산력(ANPP)지간적관계,분석료결구삼수즘양영향공능삼수.결과현시:재17 yr적할초연체과정중,군락적결구여공능균발생료변화.수착양초군락예할연체적진행,군락적공능군조성발생료현저변화,근경화초재군락중적우세지위상계피일、이년생식물、고총생화초화왜총생화초소취대.도17 yr말,군락변성근경화초、왜총생화초、고총생화초공동건군적군락.재대조군락중ANPP여년강수량현저상관,단재예할군락중이자칙불상관.년강수량해석대조군락ANPP변이적62%,이련년적예할간우칙시예할군락중ANPP동태적주요구동인자.군락정초급생산칙현출대예할간우적저항능력,재예할간우적전궤년,의고군락내공능군조성적불단조절,보지상대은정적수평,당예할진행5 yr지후,군락결구적변화적루도일정정도,정초급생산신속하강도일개교저적수평,차후의고군락결구적불단조절래유지저일공능수평.인차,군락결구시이점변적방식개변적,이군락공능적하강칙시이약변적형식완성적.군락의뢰우결구적불단조정래보지공능적상대은정,단결구변화도일정정도야회도치공능적쇠퇴.
Using field experimental data of 17 yr of mowing succession of Leymus chinensis (Trin.) Tzvel.steppe of Inner Mongolia (Nei Mongol), we analyzed the dynamics of community composition based on plant functional groups (PFGs), explored the relationship between changes of the PFGs proportion in community and the community annual net primary production (ANPP), and examined the influences of structural parameters on functional parameters. Our results showed that during 17 yr of mowing succession, changes in both community structure and function took place. The roles of different PFGs varied appar-ently with mowing succession: the dominance of rhizome grasses was replaced successively by annuals and biennials,tall bunch grasses, and short bunch grasses. Following 17 yr of mowing, the community became codominated by rhizome grasses, tall bunch grass, and short bunch grass. ANPP correlated significantly with annual precipitation in control plot, but not in successive mowing plot. Annual precipita-tion explained more than 62% of the annual variability in ANPP of control plot, whereas annual variation of ANPP in mowing plot was mainly driven by successive mowing disturbance. The community ANPP showed resilience to mowing disturbance and kept relatively stable initially through internal regulation of PFGs, and declined to a lower level with structural changes of the community after about 5 yr, and then again maintained at a stable level through structural regulation. Therefore, in mowing succession the commu-nity structure represented by PFGs changed gradually while the community function represented by ANPP declined abruptly. The community relied on constantly regulating the structure to maintain the function stability.The community function would degrade after its structure changed to certain degree.