Light utilization and competition between Echinacea purpurea, Panicum virgatum and Ratibida pinnata under greenhouse and field conditions
Light utilization and competition between Echinacea purpurea, Panicum virgatum and Ratibida pinnata under greenhouse and field conditions
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DOI：
10.1046/j.1440-1703.2002.00517.x
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发表时间：
2002-09-01
影响因子：
2
通讯作者：
Thomas, LC
中科院分区：
文献类型：
--
作者：
Knee, M;Thomas, LC
在田间和温室条件下，比较了三种代表性的高草草原物种，紫锥菊，柳枝稷和Ratibida pinnata的竞争相互作用。这些种植在单一栽培和两个物种的混合物中，使用替换系列设计，每组四个或八个植物。从在温室中120天期间和在田间415天后收集的枝条干重数据确定竞争。产量下降，增加密度的一个单一的物种在温室中从40天起，并在外地。相对产量高达100%以上的混合物比在单一栽培的所有物种早期在温室实验。在试验后期和田间试验中，E.紫斑拟青霉和红曲霉的存在降低了紫斑拟青霉和红曲霉的生长。pinnata，而E.紫花。80和120天的田间和温室试验的相对产量之间存在相关性。在温室条件下，柳枝海棠的净同化率高于其它树种。所有物种的相对生长率在单作和混作中均较高，40天后下降，尤其是E。混合物中的紫花苜蓿。在野外，桉树纯林光照强度较高;紫花苜蓿与其它树种混交林的生长量明显高于其它树种。从这些田间和温室研究中可以明显看出，竞争能力的顺序是，弗吉尼亚P.= R. pinnata > E. purpurea，可以部分解释光合速率与冠层光截获。
Competitive interactions were compared under field and greenhouse conditions for three representative tallgrass prairie species, Echinacea purpurea , Panicum virgatum and Ratibida pinnata . These were planted in monoculture and in mixtures of two species using a replacement series design with groups of four or eight plants. Competition was determined from shoot dry weight data collected during 120 days in the greenhouse and after 415 days in the field. Yields declined with increased density of a single species in the greenhouse from 40 days onward and in the field. Relative yields were up to 100% higher in mixtures than in monocultures for all species early on in the greenhouse experiment. Later in the experiment and in the field relative yields of E. purpurea decreased in the presence of P. virgatum and R. pinnata , whereas relative yields of these two species increased in the presence of E. purpurea . There were correlations in relative yield between the field and the greenhouse experiment at 80 and 120 days. In the greenhouse P. virgatum maintained higher net assimilation rates than the other species. Relative growth rates of all species were higher in monoculture and in mixtures up to 40 days, after which they declined, especially for E. purpurea in mixtures. In the field, higher light intensities occurred in pure stands of E. purpurea than in mixed stands with other species. The order of competitive ability that was apparent from these field and greenhouse studies, P. virgatum = R. pinnata > E. purpurea , could be partially explained by photosynthetic rates in relation to canopy light interception.