Typical Ecosystem Services Of Secondary Forest And Plantation In North Mountain Of Hebei

Ecosystem services are the conditions and processing through which natural ecosystems, and the species that make them up, sustain and fulfill human life. Ecosystem services in plantation can have significant difference to which in natural forest as the difference of forest source and structure between them. Larch plantation Secondary and poplar-birch forest have widespread distribution in north mountain of Hebei province. In this paper, we chose an age sequence of Secondary poplar-birch forest (SF) and Larch plantation (LP) respectively for the study of ecosystem services, and compared the services between the two forests including production of goods, carbon storage, water conservation, soil fertility maintenance and biodiversity conservation. Result showed that:(1) The tree biomass, total biomass, tree productivity and total productivity are all higher in LP than SF.Total biomass in 13-, 15-, and 30-year old LP is higher about 27.32%, 16.82%, 19.53% than 13-, 18-, and 28-year old SF, respectively, Tree biomass is the largest portion in total biomass (about 60.21%-86.59%) , then is litter, shrub and herb. Total productivity in 13-, 18-, and 28-year old SF is 6.67 t/hm2·a, 6.67 t/hm2·a and 7.10 t/hm2·a, and 13-, 15-, and 30-year old LP is 7.12 t/hm2·a, 10.27 t/hm2·a and 11.70 t/hm2·a, respectively. Tree productivity have dominion in community productivity (about 86.28-98.09% ) .(2) Carbon storage in PL is larger than in SF. Total carbon stock in LP is higher about 20% than in SF in each age class, and it increases with stand age. The tree carbon stock accounts for 64.56% - 88.92% of total carbon stock, and understory vegetation is the smallest portion. Pay attention to the carbon stock of litter, which can cover 33.84% in some stands. And litter carbon stock in LP is about twice as much as in SF.Annual variations of tree carbon stock in studied stands are low entirely. Comparison between LP and SF in the same age class, the accumulated rate of carbon stock in LP is higher than in SF in early stand development, but barely equals in late.(3) The water holding capacity in LP (2266.47t?hm-2) is higher than in SF, but the differences between forest types are non significant. So that water conservations in both forest types are ultimately equal entirely. Soil plays dominated role in forest water conservation, which accounts for more 96% of whole stand water holding capacity. Water holding capacity of aboveground in Lp is obviously higher than in SF, whereas soil maximum water capacity and non-capillary water capacity show different results. Water holding in litters account for 66.94% - 90.52% of aboveground, which have more effect in water conservation than in tree and shrub.(4) Soil organic matter, available N, P, K, total N, P, K are chose for evaluation of soil fertility. Besides soil total N, other indices in LP are a little higher or higher than in SF. Comparisons between forest types in the same age class show that: soil organic matter, available P, total N and P in 13-year old SF are higher than in 13-year old LP,available K and total K contrarily, and available N fairly; besides total K, other indices in 30-year old Lp are higher than 28-year old SF.Different soil indices have different trend with the stand age. Soil organic matter, available P, K and total N in SF decline with the stand age, total K contrarily, and available N and total P non obviously. Soil available P, K and total K in LP decline with the stand age, soil organic matter, total N, P and available N non obviously. Basically, each soil index decline with the depth of soil, but available P non obviously.(5) Biodiversities in LP have no significant differences with SF, without reference to tree, shrub or herb layer. Difference occur only in late stand development as forest management intensified, biodiversity in LP is lower than in SF. It suggests that high level biodiversity could be maintain through reasonable forest management objectives and strategies.