The leaf size/number trade-off in herbaceous angiosperms  

作　　者：Thea Whitman Lonnie W.Aarssen 

机构地区：[1]Department of Biology,Queen’s University,Kingston,Ontario,Canada K7L 3N6

出　　处：《Journal of Plant Ecology》2010年第1期49-58,共10页植物生态学报（英文版）

基　　金：Natural Sciences and Engineering Research Council of Canada Research Grant(14552 to L.W.A.),Undergraduate Student Research Award to T.W.

摘　　要：Aims In this study,we examined the extent to which between-species leaf size variation relates to variation in the intensity of leaf production in herbaceous angiosperms.Leaf size variation has been most commonly interpreted in terms of biomechanical constraints(e.g.affected by plant size limitations)or in terms of direct adaptation associated with leaf size effects in optimizing important physiological functions of individual leaves along environmental gradients(e.g.involving temperature and moisture).An additional interpretation is explored here,where adaptation may be more directly associated with the number of leaves produced and where relatively small leaf size then results as a trade-off of high‘leafing intensity’—i.e.number of leaves produced per unit plant body size.Methods The relationships between mean individual leaf mass,number of leaves and plant body size were examined for 127 species of herbaceous angiosperms collected from natural populations in southern Ontario,Canada.Important Findings In all,88%of the variation in mean individual leaf mass across species,spanning four orders of magnitude,is accounted for by a negative isometric(proportional)trade-off relationship with leafing intensity.These results parallel those reported in recent studies of woody species.Because each leaf is normally associated with an axillary bud or meristem,having a high leafing intensity is equivalent to having a greater number of meristems per unit body size—i.e.a larger‘bud bank’.According to the‘leafing intensity premium’hypothesis,because an axillary meristem represents the potential to produce either a new shoot or a reproductive structure,high leafing intensity should confer greater architectural and/or reproductive plasticity(with relatively small leaf size required as a trade-off).This greater plasticity,we suggest,should be especially important for smaller species since they are likely to suffer greater suppression of growth and reproduction from competition within multi-species vegetation.Accord

关 键 词：bud bank leafing intensity MERISTEMS plant size PLASTICITY reproductive economy 

分 类 号：G63[文化科学—教育学]