According to the Seventh National Forest Inventory (2004–2008), China’s forests cover an area of 195.45 million ha, or 20.36%
of the total land area. China has the most rapidly increasing forest resources in the world. However, China is also a country
with serious forest pest problems. There are more than 8,000 species of potential forest pests in China, including insects,
plant diseases, rodents and lagomorphs, and hazardous plants. Among them, 300 species are considered as economically or ecologically
important, and half of these are serious pests, including 86 species of insects. Forest management and utilization have a
considerable influence on the stability and sustainability of forest ecosystems. At the national level, forestry policies
always play a major role in forest resource management and forest health protection. In this paper, we present a comprehensive
overview of both achievements and challenges in forest management and insect pest control in China. First, we summarize the
current status of forest resources and their pests in China. Second, we address the theories, policies, practices and major
national actions on forestry and forest insect pest management, including the Engineering Pest Management of China, the National
Key Forestry Programs, the Classified Forest Management system, and the Collective Forest Tenure Reform. We analyze and discuss
three representative plantations—Eucalyptus, poplar and Masson pine plantations—with respect to their insect diversity, pest problems and pest management measures. 相似文献
This study was carried out to evaluate longevity of available organic materials used for sulfate-reducing bacteria (SRB) activity in vertical flow ponds (VFPs) to treat mine drainage in South Korea. Spent mushroom compost samples (SMC) were tested as substrates in VFPs and analyzed for total organic carbon in VFPs, and were collected to analyze total organic carbon (TOC), T-N, T-P, K, metals and residual cellulose to check the longevity assessment. Chemical analysis revealed that the average contents of Fe, Al and Mn in SMC of VFPs were 19,907, 32,137 and 434 mg/kg, respectively. The contents of Fe and Al in SMC of VFPs were much higher than those of the unused SMC (control), but to the contrary, those of Mn showed a reversed tendency. Average TOC content of the controls was 64.19% but in one of the VFP substrates was as low as 15.92%. This might be resulted from SRB consumed the available organic carbon in SMC as VFPs system aged. Contents of T-N in VFPs tended to decrease as VFPs aged. The residual cellulose ranged from 3.88 to 6.72% (g/g). There existed a negative relationship between residual cellulose contents and ages of VFPs. Assuming that SMC in all VFPs had similar compositions when the VFPs were initially established, trend analysis predicted that the amount of carbon source for SRB might be available for 12–15 years further, depending on VFPs.
A new method for the determination of submicromolar and nanomolar concentrations of herbicide Bifenox using differential pulse voltammetry at a mercury meniscus modified silver solid amalgam electrode is described. This new type of working electrode is non-toxic, environmentally friendly, and compatible with principles of green analytical chemistry, and its surface can be easily electrochemically renewed in the case of passivation. The newly developed direct differential pulse voltammetric determination of Bifenox gives limit of determination 6.7·10?7 and 6.9·10?7?M in drinking and river water, respectively. Both the selectivity and the sensitivity can be further increased by preliminary separation and preconcentration using solid phase extraction. This combination enables to reach limit of determination 0.9?×?10?9 and 1.5?×?10?9?M for drinking and river water, respectively. Because of lower running and investment costs, this electroanalytical method can be used for large scale monitoring of possible water contamination with tested herbicide. 相似文献
