A multi‐trait test of the leaf‐height‐seed plant strategy scheme with 133 species from a pine forest flora

Abstract

Summary1. Westoby's [Plant and Soil (1998), 199, 213] Leaf-Height-Seed (LHS) plant strategy scheme quantifies the strategy of a plant based on its location in a three-dimensional space defined by three functional traits: specific leaf area (SLA), height, and seed mass. This scheme is based on aboveground traits and may neglect strategies of belowground resource capture if root functioning is not mirrored in any of the axes. How then do fine roots fit into the LHS scheme? 2. We measured 10 functional traits on 133 plant species in a ponderosa pine forest in northern Arizona, USA. This data set was used to evaluate how well the LHS scheme accounts for the variation in above and belowground traits. 3. The three most important plant strategies were composed of multiple correlated traits, but SLA, seed mass, and height loaded on separate principle components. The first axis reflected the widely observed 'leaf economics spectrum'. Species at the high end of this spectrum had high SLA, high leaf and fine root nitrogen (N) concentration, and low leaf dry matter content. The second axis reflected variation in seed mass and fine root morphology. Plants at the positive end of this spectrum were plants with large seeds and low specific root length (SRL). The third axis reflected variation in height and phenology. Plants at the positive end of this spectrum were tall species that flower late in the growing season. 4. Leaf N concentration was positively correlated with fine root N concentration. SRL was weakly positively correlated with SLA. SRL was not correlated with fine root N concentration. Leaf litter decomposition rate was positively correlated with the leaf economics spectrum and was negatively correlated with the height and phenology spectrum. 5. Leaf traits, seed mass, and height appear to be integrating properties of species that reflect much of the variation in plant function, including root function. Fine root N concentration was positively mirrored by the leaf economics spectrum, and SRL was inversely mirrored by seed mass. The leaf and height axes play a role in controlling leaf litter decomposability, indicating that these strategy axes have important consequences for ecosystem functioning.

Seedling root responses to soil moisture and the identification of a belowground trait spectrum across three growth forms

“…Studies have made some headway in examining whether parallel trade-offs occur belowground, but general trends are elusive. For example, higher specific root length (SRL) indicates greater absorptive root length per unit biomass and, like SLA, has been linked to other attributes associated with rapid resource acquisition, such as high root respiration rate (Tjoelker et al, 2005) and low root lifespan (Eissenstat et al, 2000;McCormack et al, 2012) as well as rapid aboveground growth rates and associated leaf traits (Reich et al, 1998a;Wright & Westoby, 1999;Laughlin et al, 2010;Liu et al, 2010). However, other studies have not found correlations between SRL and growth rate metrics (e.g.…”

ORCHIDEE-PEAT (revision 4596), a model for northern peatland CO<sub>2</sub>, water, and energy fluxes on daily to annual scales

“…Previous studies have shown that there are considerable overlaps for the plant trait ranges among different plant functional types, while variations in plant traits within a PFT can be larger than the differences in means of different PFTs (Verheijen et al, 2013;Wright et al, 2005;Laughlin et al, 2010). Therefore, for simplicity, we applied only the PFT of C 3 grass with a shallower rooting depth to represent the average of vegetation growing in northern peatlands.…”

A century of increasing pine density and associated shifts in understory plant strategies

“…We measured specific leaf area (SLA), leaf dry matter content (LDMC), leaf nitrogen concentration ([N]), fine root [N], seed mass, specific root length (SRL), canopy height, and mean Julian flowering date. Trait measurement methodology is described in Laughlin et al (2010).…”

“…In prior work, we found that three orthogonal strategy axes, representing Westoby's (1998) ''leaf-height-seed'' model of plant strategies, captures the majority of functional variation in a ponderosa pine forest understory flora (Laughlin et al 2010). The first strategy axis represents variation along the ''leaf economics spectrum'' (Wright et al 2004) and is indicative of a species' ability to rapidly photosynthesize and respond to opportunities for rapid growth (Reich et al 1997).…”