Chapter

Landscape Ecological Applications in Man-Influenced Areas

pp 273-290

Element Fluxes and Budets of a Plantation Embedded in an Agroforestry LandscapeANDSCAPE: Implication for Landscape ManagementANAGEMENT and Sustainability

  • W. SHENAffiliated withSouth China Botanical Garden, The Chinese Academy of SciencesNicholas School of the Environment and Earth Science & Department of Biology, Duke University
  • , H. RENAffiliated withSouth China Botanical Garden, The Chinese Academy of Sciences
  • , Y. LINAffiliated withSouth China Botanical Garden, The Chinese Academy of Sciences
  • , M. LIAffiliated withSouth China Botanical Garden, The Chinese Academy of Sciences

Abstract

Nutrient fluxes and cycling are key processes to sustaining the structure and functioning of patches as well as the landscapes in which they are embedded. In this chapter, we synthesized a 10- year study on the nutrient cycling of an Acacia mangiumplantation located in the upper slope of a watershed landscape consisting on a tree plantation, a fruit garden, a grassland meadow, and a fishpond. Element fluxes and budgets were analyzed to derive guidelines for managing this landscape. We found that the plantation acted as a nutrient sink during its early stage of development (15-20 years since establishment), as it accumulated a large amount of nutrients on its compartment pools (i.e., plant biomass, forest floor, and soil). Over 1/3-1/6 of total litter on the plantation floor could be moved to fertilize other landscape components (e.g., the fruit garden and the grassland). However, the ability of the plantation to retain nutrients started to decrease at a fast rate when it approached near-mature development stage (20-30 years old). During this stage the risk of N saturation, soil acidification, and nutrient depletion (e.g., P, K, and Mg) increased as the plantation ages, especially under conditions of large atmospheric deposition. In order to sustain its nutrient retention ability and other ecosystem services, we suggested that application of composite P, K and Mg fertilizers are needed after the plantation reached about 20-30 years old. This study also confirmed that positioning the A. mangium plantation on the upper slope of the watershed was an appropriate spatial arrangement for the studied landscape, as it decreases the risk of transporting excessive elements into the lowland fishpond via soil erosion and surface runoff processes. Further studies on element fluxes and budgets of the other three landscape components need to be conducted in order to obtain a comprehensive understanding of interactions between landscape pattern and biogeochemical processes, and to ultimately reach a sustainable management of the landscape.