Man-Made Forests

Abstract

In recent decades, afforestation and reforestation have led to an increase in forest and tree cover; however, in most areas of SW China, establishment of plantations has not achieved ecological restoration. Several case studies done in subtropical Yunnan have concluded that planting fast-growing monospecifi c Eucalyptus or Pinus plantation forests results in poor recovery of vegetation and plant diversity, great soil surface runoff and erosion, low litter nutrient input, and poor soil nutrient storage. In contrast, natural secondary succession facilitates regeneration of secondary forests, promotes recovery of vegetation and plant diversity and replenishes litter-soil nutrients, and, as a result, yields distinctive ecological benefi ts. Consideration of various individual case studies and evaluation of emerging patterns can help to explain the results of plantation establishment in the subtropical areas. 5.1 Controversial Opinions In China, the total plantation area has reached 5.33 × 10 7 ha, accounting for 30 % of the country's forested area (SFA 2007) and 29 % of the world's total plantation area (FAO 2007). The plantation area of subtropical China accounts for 63 % of the nation's total (SFA 2007). Plantations of Eucalyptus , Pinus , Keteleeria , Cunninghamia , Cryptomeria , Larix , Populus and Betula , but especially Eucalyptus and Pinus , are widespread in this region, because of their rapid growth and high yield. Since plantation forestry contributes to economic growth, these fast-growing tree species are today being planted more and more; they produce wood, oil, pulp, and fuel, and are justifi ed as a form of restoration of vegetation, and soil and water conservation. More recently, carbon sequestration and other environmental values are also cited. With rapid development, vast monocultures have been established after deforestation all over China. In the southwest, fast tree growth and inexpensive land and labor combine to make industrial production especially popular. The pres-sure on the man-made forests to deliver economic, social, and environmental services has reached unsustainable levels in SW China.