Retuerto R, Rochefort L, Woodward F I
Area de Ecología, Facultad de Biología, Universidad de Santiago, 15706, Santiago, Spain.
Département de Phytologie, Faculté des Sciences de l'Agriculture et de l'Alimentation, G1 K 7P4, Quebec, Canada.
Oecologia. 1996 Oct;108(2):241-251. doi: 10.1007/BF00334647.
Plants in nature live in populations of variable density, a characteristic which may influence individual plant responses to the environment. We investigated how the responses of Sinapis alba plants to different wind speeds and CO concentrations could be modified by plant density. In our wind-density experiment the expectation that mechanical and physiological effects of wind will be ameliorated by growing in high density, as a result of positive plant interactions, was realised. Although individual plants were smaller at higher densities, the effect of increasing windspeed was much less than at lower plant densities. A similar reduced sensitivity of individual plant growth under high densities was also observed under CO enrichment. When measured as a population or stand response, there was no effect of density on the CO responses, with all stands showing very similar increases in total biomass with CO enrichment. In the wind speed experiment, total biomass per stand increased significantly with density, although there was no effect of density on the wind speed response. Specific leaf area decreased with increasing wind speed and this response was significantly affected by the density at which the plants grew.
自然界中的植物以密度各异的种群形式生长，这一特性可能会影响个体植物对环境的反应。我们研究了植物密度如何改变白芥植株对不同风速和二氧化碳浓度的反应。在我们的风速-密度实验中，由于植物间的积极相互作用，预期的高密度生长可减轻风的机械和生理影响得以实现。尽管在较高密度下个体植株较小，但风速增加的影响远小于较低植物密度时的影响。在二氧化碳浓度升高的情况下，也观察到了在高密度下个体植物生长敏感性类似的降低。当以种群或林分反应来衡量时，密度对二氧化碳反应没有影响，所有林分在二氧化碳浓度升高时总生物量的增加都非常相似。在风速实验中，每个林分的总生物量随密度显著增加，尽管密度对风速反应没有影响。比叶面积随风速增加而减小，并且这种反应受到植物生长密度的显著影响。
