Spatial Ecological Research Of Elliot's Pheasant

During 1999 to 2003, habitat patches and distribution of Elliot's pheasant were investigated in Kaihua county, Zhejiang province, China. The current status of habitat loss and fragmentation, and the effects of habitat patch attributes on population distribution and relative population density were analyzed. Furthermore, the Elliot's pheasant metapopulation in Kaihua county was constructed and analyzed. Also with metapopulation theory, a new method to evaluating average population dispersal distance between habitat patches was developed, and new conservation strategy on Elliot's pheasant was presented. The major results are as follows.1. A total of 284 Elliot's pheasant habitat patches in 1986 and 151 in 2000 were identified from the satellite image data using techniques of remote sensing and geographic information system. There had been lost 13309.74 ha habitat area and lengthened average nearest neighbor distance from 416.18 m to 673.93 m during 1986 to 2000, which made habitat fragmentation more seriously. Many small habitat patches had been removed and few local area had reforested, that made average habitat patches size increase from 162.11 ha in 1986 to 218.32 ha in 2000. The results of hierarchic network analysis showed that habitat patches were tighter in 1986 than in 2000 not only inter-clusters lever but also at intra-cluster lever.2. Using collecting molted feathers in line transects, a total of 52 habitat patches occupied by Elliot's pheasant were recorded in all 151 habitat patches in Kaihua county. The patch area, shape index, distance to nearest neighbor, proximity index, altitude, slope degree, slope aspect, vegetation index, distance to the nearest road, distance to the nearest village, and distance to the nearest river were selected as variables to describe each habitat patch, and the effects of those patch attributes on Elliot's pheasant were analyzed. The results t test showed that patch area, shape index, distance to nearest neighbor, and vegetation index significantly affect habitat patch occupancy. The predictable habitat patch occupancy of Elliot's pheasant was generated by binary logistic regression using all variables in a forward stepwise selection method. Here is the model: where: P(y_i=1) is the probability of being occupied in patch i, HA_i is area of patch i, PR_i is proximity index of patch i, and VIi is vegetation index of patch i. 3. The number of molted feathers which could be calculated to express as relative local population size were collected with transaction line method, and the vegetation properties were surveyed in every one of 27 habitat patches in Gutian Mountain Nature Reserve and its vicinities. The vegetation properties of habitat patch, such as total cover, arbor cover, shrub cover, arbor height, shrub height, and vegetation type, were analyzed using principal component analysis to reduce data redundancy, and its PC1 present external ecological appearance and PC2 present shrub properties. In these attributes variables, such as PC1, PC2, area, elevation, slope degree, connectivity index, disturbance index, relative location, the patch area was the only variable that showed significant positive relationship to local relative population density in t test and x 2 test. The predictable local relative population density of Elliot's pheasant was generated by multiple variables general linear model procedure in a backward stepwise selection method. Here is the model: D_i = 0.852 + 0.078PA_i - 0.137PI_i - 0.006PD_i where: D_i is local relative population density in patch i, PA_i is area of patch i; PI_i is disturbance index in patch i.4. With estimated parameters (u=0.04, x=2,α=1, b=0.5, y=2), the Elliot's pheasant metapopulation in Kaihua county was constructed as incidence function metapopulation model. This metapopulation predicted 18.0% average patch occupancy in 100 years and its long time persistence. The results of parameters (α, b, and y) sensitivity analysis showed that metapopulation persistence was significantly affected withα, which is relative to the average population dispersal distance between habitat patches. Asαreduced to 0.67, the average patch occupancy would increase from 18.0% to 34.0% in 100 years. No significant effects on metapopulation persistence took place if center-to-center nearest neighbor distance replaced with the border-to-border nearest neighbor distance in metapopulation model. When regional stochasticity enclosed in model, metapopulation persistence would decrease. If there had one of fifty years encounter regional stochasticity, the average patch occupancy would decrease from 18.0% to 8.0% in 100 years.5. Based on metapopulation principles, using spatial hierarchic cluster analysis for patchy system, the longest population dispersal distance between habitat patches is the longest nearest neighbor distance of an occupied habitat patch, the frequenty population dispersal distance between habitat patches is the longest nearest neighbor distance in a cluster with all occupied habitat patches, the average population dispersal distance between habitat patches is average value of the longest population dispersal distance and the frequenty population dispersal distance. This average population dispersal distance estimate method had been carried out software program using GIS Active X Control. With the help of some metapopulation examples, the average population dispersal distance estimated out of this program could contrast with the known value, which could validate its practicability and limitation.6. Four typical habitat patch system were chosen, and made every patch system to encounter four suppositional patch change scenario, in which the first was to lose 50% patch area, the second was to recover 20% patch area, the third was to increase 50% distance to nearest neighbor, and the fourth was to decrease 20% distance to nearest neighbor. The Elliot's pheasant metapopulation persistence in each scenario was analyzed. And according analysis results, the major principles of Elliot's pheasant conservation are: the precedence protection action should manage the whole big area with complicated habitat patch system, and recover habitat area was very important action for habitat patch system in relative isolated local region.