水保所知识产出(1956---)知识库

Ecological stoichiometry is the study of the interaction and balance of multiple chemical elements in ecological
processes. However, how ecological stoichiometric interactions among plants, soils, and enzymes in the rhizo-
sphere affect secondary plant succession is largely unknown. In this study, we collected the dominant and main
companion species Artemisia capillaris, A. sacrorum, and Stipa bungeana, along a secondary succession chro-
nosequence (7, 12, 17, 22, and 32-year) following a cropland abandonment in the Loess Plateau, China. We
measured the carbon (C), nitrogen (N) and phosphorus (P) concentrations of plant shoots and roots, as well as the
concentrations of C, N, P, available N (aN), available P (aP), and the activity of one C-acquiring enzyme
(β-glucosidase (BG)), two N-acquiring enzymes (N-acetylglucosaminidase (NAG), leucineaminopeptidase (LAP)),
and one P-acquiring enzyme (alkaline phosphatase (AP)) found in the rhizospheric soil to explore the C:N:P
stoichiometry that drives secondary plant succession. The C:P and N:P ratios in the shoots of dominant plant
species significantly decreased to a minimum value at the 22-year site and then increased with plant secondary
succession. Compared with the 7-year site, the rhizosphere soil C:P and N:P ratios, and enzyme N:P ratios (ln
(NAG + LAP):ln(AP)) increased 103.6%, 72.0%, and 221.3%, respectively, but enzyme C:N ratios (ln(BG):ln
(NAG + LAP)) decreased 48.2% in the dominant plant species at the 32-year site. Principal component analysis
indicated that the stoichiometry characteristics of the plant-soil-enzyme continuum differed for each plant
species and succession stage. Stoichiometric homeostasis indices for the plant species indicated a relatively
strong homeostasis, while redundancy analysis revealed that the variations in soil BG, NAG, and AP activity and
enzyme C:N ratio had significant effects on the stoichiometries and nutrient concentrations of the plant tissues.
The results indicated that rhizosphere stoichiometry is a powerful tool for evaluating plant-soil interactions in
terrestrial ecosystems and that the variation in rhizospheric soil enzyme activity driving the secondary succession
of plants.