Photosynthetic pathways (C3, C4, and CAM) and morphological functional types were identified for the species from vegetation in agro-pastoral ecotone, North Beijing. 792 vascular plant species (nearly half of the total species in the ecotone), in 66 families and 317 genera, were identified with C3, C4, and CAM photosynthesis (Table 1). 710 species (90 % of the identified species in Table 1) in 268 genera and 64 families were found with C3 photosynthesis, 68 species (9 % of the total identified species) in 40 genera and 7 families with C4 photosynthesis, and 14 species in 4 genera and 1 family with CAM photosynthesis. Gramineae is the leading family with C4 photosynthesis (43 species), Cyperaceae ranks the second (16 species) followed by Chenopodiaceae (5 species). The significant increase of C4 proportion (C4/total species) with land deterioration suggested the plants of this type are remarkably responsive to land use in the ecotone. 792 species were classified into nine morphological functional types and the changes of most of these types (e.g. perennial forbs (PEF), annual grasses (ANG), and annual forbs (ANF)) were consistent with habitats and vegetation dynamics in the agro-pastoral ecotone. Hence the photosynthetic pathways, combined with the morphological functional types, are efficient indications for studying the linkage between species and ecosystems in the ecotone. and X. Q. Liu, R. Z. Wang.
Photosynthetic pathways (C3, C4, and CAM) and morphological functional types (e.g. shrubs, high perennial grasses, short perennial graminaceous plants, annual grasses, annual forbs, perennial forbs, halophytes, and hydrophytes) were identified for the species from salinity grasslands in Northeastern China, using the data from both stable carbon isotope ratios (δ13C) and from the references published between 1993 and 2002. 150 species, in 99 genera and 37 families, were found with C3 photosynthesis, and most of these species are dominants [e.g. Leymus chinensis (Trin.) Tzvel., Calamagrostis epigeios (L.), Suaeda corniculata (C.A. Mey.) Bunge]. 40 species in 25 genera and 8 families were identified with C4 photosynthesis [e.g. Chloris virgata Sw., Aeluropus littoralis (Gouan) Parlat] and 1 species with CAM photosynthesis. Gramineae is the leading family with C4 photosynthesis (27 species), Chenopodiaceae ranks the second (5 species). The significant increase of C4 proportions with intense salinity suggested this type plant is remarkable response to the grassland salinization in the region. 191 species were classified into eight morphological functional types and the changes of most of these types (e.g. PEF, HAL, and HPG) were consistent with habitats and vegetation dynamics in the saline grassland. My findings suggest that the photosynthetic pathways, combined with morphological functional types, are efficient means for studying the linkage between species and ecosystems in this type of saline grassland in Northeastern China.