全 文 ：文章编号: 1007-0435( 2006) 01-0095-02 ·博士论文摘要·
松嫩草原羊草与其主要伴生种竞争与共存研究
博士生:巴　雷　导师:王德利
(东北师范大学草地科学研究所, 植被生态科学教育部重点实验室, 吉林长春 130024)
　　基于对松嫩草原优势物种羊草( Leymus chi-
nensis)及其主要伴生种的空间分布格局、植物种间
关系对割草的响应, 以及羊草、芦苇( Phragmites
communis)对营养和胁迫的适应性与种间关系的研
究,探讨了植物竞争和共存的潜在机制。野外调查和
控制实验主要结论如下:
1.羊草与其主要伴生种间的相互作用使植物
空间分布格局呈现从集聚分布向随机分布, 再由
随机分布向均匀分布转变。集聚分布是杂类草入
侵羊草种群, 以及羊草种群抵御其它物种入侵的
一种有效组织形式。
2.羊草+ 芦苇群落中, 芦苇的补偿性生长快于
羊草; 羊草+ 全叶马兰( K alimeris integr if olia)群
落中, 羊草强于全叶马兰。刈割强度越大,植物的相
对生长速率越大。4 cm 和 8 cm 刈割强度降低羊草
和芦苇间的相互作用强度; 12 cm 刈割强度使羊草
不受种间关系的影响,芦苇受竞争抑制; 8 cm 和 12
cm 的刈割强度降低羊草和全叶马兰相互作用强
度, 4 cm 刈割强度改变了植物相互作用的方向。
3.生态位重叠指数表明,羊草、芦苇在营养和
pH 值资源维度上的重叠要大于电导率和水分。
羊草、芦苇对土壤肥力和 pH 要求不十分严格, 生
态位重叠较大, 而对水分和离子胁迫的适应存在
差异。芦苇对氮素供给要求较高,是氮素有效利用
者;羊草更适应在盐碱环境中生长。天然草地上,
物种共存促进了羊草和芦苇在水分资源维的生态
位分化。
4. 生物量分配格局表明羊草、芦苇之间存在
强烈的光竞争。植物体中氮素和非结构性碳水化
合物的分配格局和浓度变化表明芦苇相对羊草是
资源的有效利用者。此外, 生长分析指数(尤其是
净同化速率)和叶绿素浓度的结果证实芦苇在光
利用和转化过程中竞争优势明显。
5. 控制实验的结果表明, 低营养条件下相对
产量总和( RT Y)接近 1,羊草和芦苇对环境中的
限制性资源具有共同要求。羊草、芦苇高营养条件
下建立互惠关系, 实验群落产量较高,主要因为植
物间的竞争效应增加了植物对环境资源的利用效
率,或者是由于两物种的资源利用格局在时间和
空间上存在分化。
基于对实验结果的综合分析,提出“资源竞争
和非资源胁迫对植物的适应选择机制”假说, 即
营养丰富条件下,具有高资源捕获力和转化力的
植物是竞争优势者,且竞争优势随营养条件的提
高而增加;营养贫瘠条件下,具有低资源需求且低
消耗的物种是竞争优势者, 且竞争力随环境营养
变化不明显; 非资源胁迫因素存在时,植物竞争力
由植物对资源的捕获能力(营养丰富)或对资源的
忍耐力(营养贫瘠)与对非资源胁迫的忍耐力共同
决定;两者权衡的 4结果决定植物的竞争优势, 而
且植物的适应性贯穿于整个选择过程。
关键词: 松嫩草地; 竞争; 共存; 羊草; 芦苇; 资源; 适应性
中图分类号: S948. 12　　文献标识码: A
论文完成时间: 2005年 12月
收稿日期: 2006-01-22; 修回日期: 2005-02-27
基金项目: 国家自然科学基金项目(编号: 30571318) ;教育部(博士点基金)项目;东北师范大学自然科学青年基金项目(编号: 20060402)
作者简介: 巴雷( 1977-) ,女,理学博士,讲师,主要从事植物种间关系研究, E-mail : b al337@nenu. edu. cn
导师简介: 王德利( 1963-) ,男,教授,从事放牧生态学和理论生态学研究, E-mail : w angd@ nenu. edu. cn
第 14卷　第 1期
　Vo l. 14　 No . 1
草　地　学　报
ACT A AGRESTIA SIN ICA
　　　2006年　 3 月
　March　 2006
Competition and Coexistence of Leymus Chinensis and its Main
Companion Species in the Songnen Grasslands
Candidate: BA Lei Superviso r: WANG De-li
( Ins t itute of Gras sland Science, Key Laboratory of Vegetat ion Ecology of M inist ry of Educat ion,
Northeast Normal University, C han gchun, J ilin Province 130024, China)
The mechanism o f plant compet it ion and coexistence w as invest igated by studying the spat ial dist ribut ion
pat tern and the response of inter -specif ic compet it ion to cut t ing betw een L . chinensis and its main companion
species; more part icularly , the relationship between the adaptat ion of L . chinensis and Phrgmites communis, and
their inter-specific inter act ion. Main conclusions of field invest igat ion and contr olled experiment are as follow s:
1. The competit ive interact ion among species enforced the change of pat tern type from aggregated to r an-
dom dist ribut ion, then to even and regular distr ibution. T he fo rming of agg regated dist ribut ion is an eff icient
pat tern fo r the companion species to invade into the communit ies dom inated by L . chinensi s, and for L . chinensis
to fend of f other species.
2. P . communis grows faster than L . chinensis in the mixed communit ies of both species. L . chinensis is a
superior competitor compared to K al imeris interif olia in the m ixed communities of the tw o. Cut t ing increases
the grasses growth r ate. T he interact ive intensity betw een L . chinensis and P . communis is reduced to zero w ith
4 cm and 8 cm cut t ing . T he grow th of L . chinensis is l it t le affected by inter -specific interact ion w ith 12 cm cut-
ting , though compet ition checks the gr ow th of P. communis. T he interact ive relationship between L . chinensis
and K . inter if olia is reduced w ith 8 cm and 12 cm cut t ing . With 4 cm cut t ing , the direction of interact ion is
changed.
3. T he index of niche overlap indicates that the overlap on the soil nut rient and pH value is larger than that
on the conductance and so il moistur e dimension for L . chinensis and P . communis. T he demand of bo th species
on the soil nut rient and pH value is similar , but different in soil moisture and salt ion. P . communis favor s habi-
tats w ith high level of nit rog en, and is an effect ive user o f the nutrient . L . chinensis is more adapt ive to habitats
w ith salt-alkal i st ress. The coexistence betw een L . chinensis and P . communis improves the possibil ity of niche
dif ferent iat ion on the so il mo isture in the natural grasslands.
4. There is intense light competit ion betw een L . chinensis and P. communis, because more biomass is allo-
cated to leaf w hen soil nut rients increase. T he allocat ion o f nit ro gen and non-st ructure car bohydrate and their
concentrat ion indicate that P . communis is a more ef fective user o f natural resources than L . chinensis. Results
of gr ow th analysis and the concentrat ion of chlorophyll also confirm that P. communis could assimilate more
light and dom inate the upper layer of community to boost the ability o f absorbing soil nutrients.
5. Results in the part ially cont ro lled exper iment suggest that the demand o f L . chinensis and P . communis is
sim ilar on the same resources w hen the value of relative y ield total equals 1 at a poor nutrient level. A posit ive
relationship ex ists betw een the species at a high nutr ient lev el, as the compet it iv e r elat ionship improves the ut i-
lizing eff iciency of resources, w hile the differences of space and g row th time of the tw o facilitate the resource u-
tilizat ion.
The hypothesis on “Select ion mechanism of plant adaptat ion to resources and non-resources st ress”has
been proposed based on the results of our experiments. It is reasoned that a plant with high capability in tap-
ping and employing resources is the superior compet itor in a rich nutr ient habitat ; it s compet ing ability increas-
es w ith the abundant furnishing of nutr iments. Under a poor nutrient condit ion, plants acquiescing to low de-
mand and low expense o f nutrients are w inner s, and their compet itiv e ability does no t change w ith the shift o f
condit ions. When there is non-resource stress on plants, the outcome of compet it ion is determined by the capa-
bility of tapping and employing r esources under rich nutr ient condit ions, and that of acquiescing to low demand
and expense of nutr ients in a nutriment-lacking situat ion, as w ell as the endurance to non-resource st ress.
Key words: Songnen g rasslands; Compet it ion; Coexistence; Spatial dist ribut ion pattern; M ow ing; Nutri-
ent ; Adaptat ion.
(责任编辑　才　杰)
96 草　地　学　报 第 14卷