Response of photosynthesis of different plant functional types to environmental changes along Northeast China Transect

Abstract

Net photosynthesis (P n ), transpiration (E), stomatal conductance (g s ), internal CO 2 concentration (C i ), and water use efficiency (WUE) were examined on 215 species from eight plant functional types (PFTs) along a precipitation gradient in northeast China (the Northeast China Transect, or NECT). Among the eight PFTs, meadow steppe grasses had the highest rates of net photosynthesis and forest grasses the lowest and the following order of P n was noted: meadow steppe grasses >typical steppe grasses >steppe shrubs >desert grasses >forest trees >forest shrubs >desert shrubs >forest grasses (P<0.05). Transpiration tended to be the highest in the steppe grasses and lowest in forest shrubs. Transpiration also decreased rapidly with the appearance of C 3 desert species at the desert end. The forest tree PFT had lower P n , E, g s than the steppe PFTs, whereas WUE values were somewhat greater in the forest tree PFT than the desert shrubs and grasses. Low C i values along the steppe section (from 400 to 1100 km, east to west) indicated the presence of C 4 species. Of all the PFTs, only shrubs and herbs were noted at all points along the transect. No clear relationship between P n , E, g s , WUE of herb and shrub PFTs and annual precipitation was noted -low values were found at both the high and low precipitation ends of the transect. Highest values were noted when precipitation was intermediate.

Leaf osmotic potentials of 104 plant species in relation to habitats and plant functional types in Hunshandak Sandland, Inner Mongolia, China

“…2) may be associated with high photosynthetic rates (Jiang et al 1999) and accumulation of photosynthesis-soluble sugars (Walter 1974;Lawlor and Cornic 2002). It has been well documented that accumulated osmolytes derived from photosynthesis-soluble sugars induce low osmotic potential in some species (Guicherd et al 1997;Alarcón et al 1993;Mendes et al 2001).…”

Plant functional types and climate along a precipitation gradient in temperate grasslands, north-east China and south-east Mongolia

“…All species were classified into C 3 and C 4 categories on the basis of the photosynthetic pathways from the previous identifications (Yin & Li, 1997;Yin & Wang, 1997;Jiang et al, 1999;Tang, 1999). The PFTs of grass, shrub, and forb were classified according to the information from field investigation and herbarium.…”

“…Other PFTs, such as shrubs and forbs, were poorly considered. Jiang et al (1999) reported the response of photosynthesis of eight PFTs to environmental changes on the NECT, but there was lack of quantitative analyses of relationships between PFTs and climate.…”

“…The general features of the transect have been described previously, including vegetation and climate variability (Ni & Zhang, 2000). The characteristics of photosynthesis of PFTs (Jiang et al, 1999) and C 4 plant distribution related to environmental factors (Tang, 1999) were analysed. Some statistical and process-based modelling of vegetation and their responses to global change were also performed based on vegetation and/or PFTs (Li, 1995;Gao & Yu, 1998;Ni, 2000).…”

Effects of climatic change on biomass and biomass allocation in Leymus chinensis (Poaceae) along the North-east China Transect (NECT)

“…Most transect studies focused on the effects of climatic and geographical variations on ecosystem production and vegetation distribution (Li, 1995;Zhang et al, 1997;Cao & Woodward, 1998;Gao et al, 2000;Ni & Zhang, 2000;). Some have tested the response of photosynthesis of plant functional types to climatic changes along terrestrial transect (Jiang et al, 1999;Wang, 2002). Few have looked at the influences of large-scale climatic changes or geography gradients on plant morphology (Wang, 2001) and mortality (Villalba & Veblen, 1998).…”