Study On The Main Ecological Function Of Five Ecological Forests In Hunan Province

Hunan province had completed the division of its ecological forest area based on the stated area proportion. The scientific, systematic and proper evaluation had been a priority after the division of ecological forestry area. Combining with ecological benefit of Hunan Forest Resources in monitoring indicator and monitoring method, this research analyzed the major ecological functions of five kinds of ecological forest (ⅠRiver source,ⅡCross rivers,ⅢNational Nature Reserve,ⅣWetlands and Reservoirs andⅤUrban landscape forest types) with the measured data, and reflected the ecological status of ecological forest. The result show that:(1)The changes of Shannon-Wiener index and Simpson index follow the same trend in different forest types, the mixed evergreen broad-leaved bio-diversity were bigger than the coniferous forest; bio-diversity levels of ecological forest were higher than the same type Non-ecological Forest.(2) Stand in the ecological forest,the biomass ofⅡtype pine forest were the largest(13.04t·hm -2),others followed by:Ⅰtype,Ⅲtype,Ⅳtype,Ⅴtype;the litter storage of the mixed forest originated in the natural are bigger than plantation; the largest water holding of litter changed in the range of 159.54%～291.04%,and the water holding capacity ofⅠtype litter were the best.The water holding capacity of the non-ecological forest ground cover layer were lower than ecological forest in the same types.(3) In terms of the mean soil bulk density,Ⅲclass ecological forest occupied lowest, while the natural mixed forest had obvious improvement in soil structure of plantation forest. The Noncapillary porosity of every soil layer reduced along with the increase of soil depth. The order of maximum water storage for different types of ecological forests wasⅠtype>Ⅱtype>Ⅲtype>Ⅳclass>Ⅴclass, with the effective storage capacity ranged 131.28～318.9t·hm-2.The ecological forest's land permeability ofⅢclass was the best, which related to the better soil physical properties. The maximum water-storage capacity of ecological forest was larger than that of non-ecological forest. (4) The soil pH of the five different ecological forest types ranged between 4.48～5.57,and the soil characteristical showed weak acid; soil organic matter and total nitrogen content decreased with soil depth increases. soil organic matter of the natural mixed forest and total nitrogen content were larger than plantation forest. Soil total phosphorus and available phosphorus had not change law, and total K was on the contrary. the highest content of soil heavy metals was Mn, and the lowest was Cd. The order of 5 average content of heavy metaled from High in the end is:Mn> Zn> Pb> Cu> Cd.4 kinds of soil heavy metal content--Mn, Zn, Pb and Cd of III class was the lowest. Heavy metal content of soil was influenced by different types of forest.(5) The carbon storage of vegetation and litter changed in the range of 27.908～44.556 t·hm-2 in different ecological forest types,which the type I was the biggest; The carbon storage size of soil (0-45cm) changed from 88.446 to 112.644 t·hm-2,which the III type evergreen broad-leaved was the maximum.The ecosystem carbon storage size changed in range of 116.354～155.135 t·hm-2,and their carbon storage followed by:III type> IV type> I type> V type> II type. The carbon storage of the non-ecological forest ecosystem were higher than ecological forest in the same types,which the soil carbon storage dominated in the carbon storage of forest ecosystem.