A community-level test of the leaf-height-seed ecology strategy scheme in relation to grazing conditions Golodets, Carly Ã1 ; Sternberg, Marcelo 2,3 & Kigel, Jaime 1,4 1 Robert H. Smith Institute for Plant Sciences and Genetics in Agriculture, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, PO Box 12, 76100 Rehovot, Israel; 2 Department of Plant Sciences, Faculty of Life Sciences, Tel Aviv University, 69978 Tel Aviv, Israel; 3 Email marcelos@tauex.tau.ac.il; 4 Email kigel@agri.huji.ac.il; Ã Corresponding author; Fax 1972 8 9467763; Email adonis@agri.huji.ac.il Abstract Question: Is the assumption of trait independence implied in Westoby’s (1998) leaf-height-seed (LHS) ecology strat- egy scheme upheld in a Mediterranean grazing system dominated by annuals? Is the LHS approach applicable at the community level? Location: Northern Israel. Methods: LHS traits (specific leaf area [SLA], plant height and seed mass), and additional leaf traits (leaf dry matter content [LDMC], leaf area, and leaf content of nitrogen [LNC], carbon [LCC], and phosphorus [LPC]), were analyzed at the species and community levels. Treatments included manipulations of grazing intensity (moderate and heavy) and protection from grazing. We focused on species comprising 80% of biomass over all treatments, assuming that these species drive trait relationships and ecosystem processes. Results: At the species level, SLA and seed mass were negatively correlated, and plant height was positively correlated to LCC. SLA, seed mass, and LPC increased with protection from grazing. At the community level, redundancy analysis revealed one principal gradient of variation: SLA, correlated to grazing, versus seed mass and plant height, associated with protection from grazing. We divided community functional parameters into two groups according to grazing response: (1) plant height, seed mass, LDMC, and LCC, associated with protection from grazing, and (2) SLA, associated with grazing. Conclusions: The assumption of independence between LHS traits was not upheld at the species level in this Mediterranean grazing system. At the community level, the LHS approach captured most of the variation asso- ciated with protection from grazing, reflecting changes in dominance within the plant community. Keywords: Community functional parameters; Mediterra- nean grassland; Plant traits; Redundancy analysis. Nomenclature: Feinbrun-Dothan & Danin (1991). Abbreviations: LHS 5 Leaf-Height-Seed, SLA 5 Specific leaf area, LDMC 5 Leaf dry matter content, RDA 5 Re- dundancy analysis, LNC 5 Leaf nitrogen content, LCC 5 Leaf carbon content, LPC 5 Leaf phosphorus content. Introduction Plant ecology strategy schemes enable the cate- gorization of plant species responses to disturbance, competitive ability, and dispersal capability, and their roles in ecosystem functioning. This categor- ization facilitates reduction of the diversity of plant species responses to a few, easily defined categories with meaningful ecological significance. Two major dimensions of ecological variation are the ability to cope with disturbance and adaptation to fast versus slow growth opportunities (Westoby et al. 2002). The current challenge is to define how these dimen- sions are represented in plant response traits, and to link them to ecosystem functioning (Weiher et al. 1999). Raunkiaer’s (1937) life form scheme has been widely used for decades and its life form definitions are incorporated into vegetation analyses as a matter of course. Grime’s (1974, 2001) competitive- stress tolerant-ruderal (C-S-R) scheme is also frequently used. More recently, Westoby (1998) proposed the leaf-height-seed (LHS) scheme as an alternative method to summarize all major dimen- sions of variation in plant responses to their environment. This scheme was developed for use at global scales, and is therefore based on easily mea- sured plant traits: canopy height, specific leaf area, and seed mass. Each of these three traits represents a fundamental trade-off that controls plant strategies, so that differences in trait values between species are Journal of Vegetation Science 20: 392–402, 2009 & 2009 International Association for Vegetation Science