Literature review of key site and management factors influencing the growth of trees in low rainfall areas of Australia

[摘要] This literature review is part of a large project to refine the National Inventory (DCCEE 2011) for environmental and mallee plantings, which was commissioned by the Department of Climate Changeand Energy Efficiency (DCCEE). The aim of the review was to collate, review and synthesise literature on the effects of various site characteristics and management practices thought to be most relevant to the growth of oil mallee and environmental plantings. Considering the environments in which they are currently or likely to be grown, and current management practices, growth is likely to be limited by (i) water availability, (ii) soil fertility and (iii) soil salinity. We reviewed management and site selection factors that will influence water availability, previous management impacts on soil fertility and the effect of salinity on growth. In addition, the oil mallee industry envisions that oil mallees will be grown for both bioenergy and below-ground carbon sequestration, in a frequently harvested system. Therefore, we examined the literature on the impacts of multiple harvesting and coppicing regimes on tree growth.It was apparent from the literature that there is limited information on the factors affecting growth of perennial vegetation in low rainfall environments, and that where information does exist vast differences are reported in response to management depending on interactions between climate, site factors, species and multiple types of management events. In addition, it is difficult to quantify sitecharacteristics (e.g. soil depth, salinity, depth to groundwater) that impact growth at fine spatial scales. Another complicating issue is the sustainability of new production systems under low rainfall and low fertility environments, and the interaction between seeking high productivity and the increased risk of mortality. We concluded that it is not possible to reliably predict tree growth rates at specific locations in the landscape where multiple and complex interactions affect the pattern of biomass production. Likewise, temporal change in growth under changing site conditions, varying management regimes, or after multiple harvests is also very difficult to predict. Thus use of ‘generalized’ modifiers in models will result in high error at the local scale, but these may be more robust when applied at broader scales.

[发布日期] 2011-06-30 [发布机构] CSIRO

[学科分类] 地球科学(综合)