Distribution of biomass of species differing in photosynthetic pathway along an altitudinal transect in southeastern wyoming grassland

Abstract

Based on the physiological characteristics and responses of C, C, and CAM plants to environmental factors, it is generally predicted that C and CAM plants will become more abundant with increasing temperature and decreasing precipitation. To test this prediction, the relative contribution of each photosynthetic type to total plant community biomass was examined at seven study areas along an altitudinal transect in southeastern Wyoming grassland. In going from high (2,652 m) to low (1,405 m) elevation along this transect, mean annual temperature increased and annual precipitation decreased.The percentage of C biomass composing each study area decreased with increasing elevation, while the percentage of C biomass increased. All elevations had a significantly higher percentage of C biomass in August than in June, reflecting the warm season growth characteristic of C plants. Regressions of relative abundance of photosynthetic types on climatic variables showed that both mean annual temperature and annual precipitation were equally reliable as predictors of C-C biomass, although we feel that temperature is of primary importance in explaining our observations. CAM species were present at all elevations, but showed no trends in biomass distribution with respect to elevation.

Changes in Community-Level Riparian Plant Traits over Inundation Gradients, Colorado River, Grand Canyon

“…Seed mass data were compiled from the KEW Royal Botanic Garden Seed Information Database (Royal Botanic Gardens Kew 2016, http://data.kew.org/sid/), and consist of average weight in grams per 1000 seeds. Photosynthetic pathways (C3 or C4) were not found for all species, but if another species in the same genus was available, we assumed the same pathway for the species of interest (Syvertsen et al 1976;Doliner and Jolliffe 1979;Waller and Lewis 1979;Boutton et al 1980).…”

Local distribution of C3 and C4 grasses in sites of overlap on Mount Kenya

“…As long as there is sufficient diversity of microsites at a given locale, both C 3 and C 4 species could coexist. Temporal separations of C 3 and C 4 plants in communities have been measured and found to be significant in Wyoming (Boutton et al 1980), Colorado (Kemp and Williams 1980), and South Dakota (Ode et al 1980). These studies found C 3 species to be dominant, in either biomass or frequency, in the spring.…”

“…Multivariate analyses of the abundance of C 3 and C 4 grasses and herbs of North America have indicated that high moisture availability and low temperatures are strong correlates of relative C 3 abundance (Teeri and Stowe 1976;Stowe and Teeri 1978). Large-scale elevational transects in Wyoming (Boutton et al 1980), Kenya (Tieszen et al 1979), and Costa Rica (Chazdon 1978) show, with increasing elevation, a transition from C 4 to C 3 as the predominant photosynthetic pathway. Both drought stress and temperature tend to decrease with increasing elevation in these studies.…”

Carbon isotope of bulk organic matter: A proxy for precipitation in the arid and semiarid central East Asia

“…[3] Under constant atmospheric CO 2 concentration, dominance of the different photosynthetic pathways to a community is climate-dependent [Teeri and Stowe, 1976;Stowe and Teeri, 1978;Teeri et al, 1980;Boutton et al, 1980;Epstein et al, 1997;Sage et al, 1999]. Modern C3 plant dominates in the high latitude forest, tundra and most temperate grassland, while the C4 plant are most abundant in hot, semiarid environments with high light intensity such as grasslands, savannas, deserts and salt marshes, CAM plants are only important in some desert environment.…”

“…[4] Among the climatic variables, temperature is a predominant determinant on the distribution of modern C3 and C4 vegetation around the world [Teeri and Stowe, 1976;Stowe and Teeri, 1978;Teeri et al, 1980;Boutton et al, 1980;Epstein et al, 1997], while precipitation is believed to play only a secondary role [Sage et al, 1999]. Therefore a linkage between the isotope signature of SOM and temperature is presumably a priori owing to the plant propagation.…”