Root Ecological Niche Index and Root Distribution Characteristics of Artificial Phytocommunities in Rehabilitated Fields
Tóm tắt
In the implementation phase of the Conversion of Cropland to Forest and Grassland (CCFG) project in China, it is important, from a scientific point of view, to recognize phytocommunities’ characteristics, species compatibility, and ecological function. The ecological niche that roots occupy, their abundance and distribution, and the factors that affect them must be acknowledged. Following the methodology of community ecology, the total root mass of a phytocommunity is measured as cubic volume. Root biomass, length, and the number of roots in every diameter class, for each soil layer and for each plant species, are regarded as observation variables. In the first instance therefore, a new method to calculate the root ecological niche index (RENI) is proposed, embracing the entire phytocommunity of plantations. Using the new method, the roots of phytocommunities in Datong County, Qinghai Province (one of the counties selected for the national CCFG experiment), are dealt with in this paper. The results show that most of the vertical distributions of plant roots belong to the type wherein the roots are concentrated in the topsoil layer (0–20 cm), far more than those in the lower soil layers. The RENI of phytocommunities is higher than that of pure stands or monocultures. The distribution of RENI by root diameter can be divided into four types: J-type, inverse J-type, recumbent S-type, and U-type. RENI is positively correlated with the wet biomass of aboveground level stems, branches, and plant leaves, and with the species richness of phytocommunities. Although the RENIs of plantations in rehabilitated fields are a little lower than those of natural forests, they are higher than those of cultivated crops. The RENIs of three community types (Picea crassifolia + Hippophae rhamnoides ssp. sinensis, H. rhamnoides ssp. sinensis, and P. crassifolia) in rehabilitated fields benefit greatly from the restoration project. The implementation of the CCFG project is important for the increase in RENI and the multiple functions of plant roots.
Tài liệu tham khảo
Chen W. and Xue L., Root interactions: competition and facilitation, Acta Ecol. Sin., 2004, 24(6): 1243–1251 (in Chinese)
Huang J.-H., Han X.-G. and Chen L.-Z., Advances in the research of (fine) root biomass in forest ecosystem, Acta Ecol. Sin., 1999, 19(2): 270–277 (in Chinese)
Li Y., Xu X.-Q. and Zhu X.-M., Study on validity of improving soil physical properties by artificial Chinese pine roots in the Loess Plateau, Sci. Silv. Sin., 1993, 29(3): 193–198 (in Chinese)
Li Z.-W., Yang Y.-S. and Wu Y.-X., Study on roots of mixed forests of Chinese fir and phoebe, Chin. J. Ecol., 1993, 12(1): 20–24 (in Chinese)
Liu J.-J., A review on root ecology of forest trees, J. Northwest For. Coll., 1998, 13(3): 74–78 (in Chinese)
Wang R.-Z., The niche breadths and niche overlaps of main plant populations in Leimus chinensis grassland for grazing, Acta Phytoecol. Sin., 1997, 21(4): 304–311 (in Chinese)
Yu S.-X. and Orlioci L., Multivariate measure of niche breadth, Acta Ecol. Sin., 1994, 14(1): 32–39 (in Chinese)
Yang W.-Q. and Song G.-Y., Theory of soil niche and its application, World Sci. Technol. Res. Dev., 2001, 23(2): 21–23 (in Chinese)
Borm W., Roots Study Method, Beijing: Science Press, 1985, 18–95 (in Chinese)
Zhao J.-R., Sun L.-D. and Zhu J.-Z., Study on Shrubs for Soil and Water Conservation in the Loess Plateau, Beijing: China Forestry Press, 1994, 33–34 (in Chinese)
Hu J.-Z., Experimental Method of Plant Introduction and Cultivation, Zhenzhou: Yellow River Water Conservancy Press, 2002, 101–108 (in Chinese)
Shan J.-P. and Tao D.-L., Overseas research trends on tree fine roots, Chin. J. Ecol., 1992, 11(4): 46–49 (in Chinese)
Zhu Q.-K. and Zhu J.-Z., Sustainable Management Techniques of Converting Cropland into Forestland and Grassland in the Loess Plateau, Beijing: China Forestry Publishing House, 2003, 179–186 (in Chinese)
Ge F., Modern Ecology, Beijing: Science Press, 2002, 251–258 (in Chinese)
Song R.-Y., Li Q.-F. and Niu C.-J., Basic Ecology, Beijing: Higher Education Press, 2002, 140–144 (in Chinese)
Hutchinson G. -E., A Treatise on Limnology: Geography Physics and Chemistry, New York: Wiley, 1957, 11–53 (in Chinese)
Zhou D.-P. and Zhang J.-Y., Engineering Technique of Plant Protection for Slope, Beijing: China Communications Press, 2003, 62–78 (in Chinese)
Wang C., Jing Y.-H. and Liu J.-S., Root biomass of natural Japanese red pine in Yanbian area, J. Beijing For. Univ., 1999, 21(1): 44–49 (in Chinese)
Liang J.-P., Liang Y.-Z., Zhang Y.-L., Study on the root biomass of Pinus tablaeformis Carr., Henan Sci. Spec. Issue, 1999, 17: 77–79 (in Chinese)
Hu J.-Z., Discussion on fuzzy cluster and rules of growth and distribution of seabuckthorn roots, Sci. Silv. Sin., 1992, 28(1): 22–29 (in Chinese)
Grinnell J., The niche-relationship of the California thrasher, Auk, 1917, 34: 427–433
Zhang G.-M. and Xie S.-C., Development of niche concept and its perspectives: a review, Chin. J. Ecol., 1997, 16(6): 46–51 (in Chinese)
Zhou J.-L., Zheng S.-Z. and Yang C., Plant Population Ecology, Beijing: Higher Education Press, 1992, 34–97 (in Chinese)
Song Y.-C., Vegetation Ecology, Shanghai: Eastern China Normal University Press, 2001, 45–61 (in Chinese)
Li B., Survey and analysis for phyto-community, In: Jiang S. (ed.), Method of Grassland Ecology, Beijing: Agricultural Press, 1989, 45–79 (in Chinese)