FIGURE 3.

Parallel patterns for drought, shade, and nutrient scarcity of generating and applying low resource tolerance traits. The first column (A–C) shows examples of response curves for water (photosynthetic rates vs. leaf water potential for a C₄ grass; Baruch et al., 1985), light (relative growth rate of stems vs. irradiance for a temperate understory tree; Lusk, unpublished), and nutrient availability (growing season biomass vs. nitrogen mineralization rates for a C₃ grass across a gradient of soils with different soil organic matter levels; Wedin and Tilman, 1990; Wedin and Tilman, 1993). The second column (D–F) shows examples of relationships between low resource tolerance traits and differential performance of species: relative abundance of grassland species in drier uplands vs. wetter lowlands (difference in log-transformed cover; Tucker et al., 2011); tradeoffs in growth of temperate trees in high light (years to reach 3 m in height) vs. survivorship in low light conditions (Kobe et al., 1995), and relative abundance of species in experimental diversity plots vs. root length density of species grown in monoculture on soils with low nutrient availability (Fargione and Tilman, 2006).