Habitat Fragmentation And Its Influence On Red Deer Population Distribution Based On Geomatics Technique

Fragmentation habitat and its influence on red deer population distribution were studied systematically in the Wandashan Mountains in Heilongjiang Province during three successive winters from November of 2001 to February of 2005. Based on field survey, the main results by geomatics technique (3S) and multiple statistics analysis were revealed as followings:1 Analysis of habitat fragmentation factors of red deer in winter and its characteristics of spatial pattern:(1) The nine factors were main ecological ones among the fourteen that had an infuence on habitat fragmentation of red deer in winter. Further analysis showed that human activity, a synthetical factor, played a main role in habitat fragmentation of red deer in winter, including forest logging, agricultural reclamation, settlement extension, road construction and material transportation.(2) Logistic regression model was established: log (P_i/1-P_i) =-1.963 + 0.816PC₁ — 0.262PC₂ — 0.039PC₃, which classification rate correctly was 71.1%. Hence it was believed that the model may reflect the distribution of habitat fragmentation factors of red deer during winter by way of PCA (principal component analysis) and binary logistic analysis.(3) Spatial autocorrelation analysis indicated that main spatial pattern characteristics of habitat fragmentation factors of red deer in winter were as following: a) under fourteen distance grading (230³220 m), nine habitat fragmentation factors had spatial autocorrelation significantly (p < 0.05) and Moran's I reached at 73%; b) ungulate disturbance appeared negative correlation significantly during the nearer disturbance grading, which revealed that there was niche competition among red deer, roe deer and wild pig to some extent, and this disturbance distributed fragmentally and the sizes of these patches fluctuated from 230 to 920m; c) settlements, abandoned logging roads and farmlands appeared correlated significantly during all fourteen distance grading which indicated not only higher consistency in influecing on the spatial pattern of habitat fragmentation but also their important role in the process of habitat fragmentation of red deer in winter; d) semi-variance analysis and analysis on fractals showed that "nest structure" characteristics of the changes of semivariance of population distribution with the changes of spatial distance degrading, which pointed out that there was a multiple scale variation in spatial pattern of red deer distribution; e) however, fractal number-D of red deer distribution approached 2, which indicated the variation of spatial pattern of red deer distribution mainly occurred at smaller scale, i.e. differences of track number of red deer occurred in sample sites were very large, and small number came after a period time of large number. The above revealed that multiple scale of red deer distribution, grading patches of spatial distribution and vulnerability of red deer miro-habitat, i.e. once microhabitat changed, spatial pattern of red deer distribution may change greatly.2 Analyses of fragmented habitat evaluation and landscape structure(1) By analysis of the importance of landscape factors, landscape connectivity, assessment of suitability and fuzzy value of connectivity, and establishment of a landscape connectivity model that applied landscape ecology and GIS technology, the connectivity level, suitability assessment and fragmentation status of all types of suitability areas were studied. The habitat of red deer was divided into four classes: suitable, marginally suitable, less suitable and unsuitable from high quality to the low. The result indicated that suitable habitats were 14.81 km2 (only 9.52%), marginally suitable habitats were 9.57 km2 (6.15% ), less suitable habitats were 130.05 km2 (83.58%), unsuitable habitats were 1.17km2 (0.75%) in the total area of 155.6 km". In addition, among 51 patches in study area, the number of suitable habitat patches (23) was the most, accounting for 45.10%, but the numbers of less suitable habitats (5 patches) and unsuitable habitat (6 patches) were the least, accounting for 9.80% and 11.76% respectively.(2) Three landscape indices of describing the landscape pattern and change used presently, Mean PARA, Mean FRAC and Mean CONTAG, were introduced to estimate the landscape characteristic of the above four classes. The result indicated that the Mean PARA of suitable habitat (332.43) was the highest, but its Mean FRAC (1.050) and Mean CONTAG (0.749) were the lowest; while, the Mean PARA of unsuitable habitat (186.16) was the lowest, its Mean FRAC (1.059) was higher and its Mean CONTAG (0.837) was the highest, which indicated fully that the suitable habitat was more fragmented more isolated and heterogeneous than unsuitable habitat.3 Influence of forest logging on fragmented habitat selection and use of red deer in winter(1) Red deer heavily used clear-cutting land (SI=0.29) and mixed broadleaf forest (SI=0.08) which were selected positively, while selected negatively mixed coniferous and broadleaf stands, mixed poplar broadleaf forest, planted larchen forest, brush land and bare land, and did not use farmland completely (SI=0). Habitat with low arbor crown density was heavily and positively selected by red deer (SI=o.62), and with middle arbor crown density was positively selected (SI=0.16), but with high arbor crown density was selected negatively.(2) Red deer selected positively the habitat range from 600 m to 1 km to open road, while hardly appeared in the ranger of 100 m to open road.(3) Settlements due to occuring to frequent human activity around it formed a buffer zone to red deer with radium 2.74 km, where no activity of red deer had been observed.(4) Red deer used higher the habitat that was logged at the middle or high frequency (logged one to five times during the recent 15 years), while used lower tht habitat of being logged at the low frequency (no logging in the recent 15 years).(5) With the extension of logging interval, the clear-cutting land experienced succession of different vegetation, which led to difference in abundance and availability of food. The forest that was logged in 7 years showed the higher suitable to red deer, where abundance and availability of food was comparatively higher. On the contrary, red deer used lowly the habitatthat was logged 7 or more than 7 years ago.(6) At present, clear-cutting and selection-cutting were two main logging way in the study area. Clear-cutting had a great change on landscape including component and structure, while selection-cutting had little influence. Red deer had no use planted forest (0.00%) after clear-cutting, had low use rate of natural secondary forest (4.40%) after clear-cutting, while had high use rate of newly clear-cutting and selection-cutting habitat (54.40% and 41.21% respectively).4 Effect of fragmented habitat edge on population number and distribution of red deer in winter(1) Forest-shrub edge and farmland-forest edge had different edge effects on population number and distribution of red deer in winter significantly, and significant difference existed them by analysis of Mann-Whitney U (U=3.000, Z =-3.130, P=0.002). Forest-shrub edge had a positive effect on activity and distribution, which meant the activity and distribution density of red deer was higher than those in bordered on interior of shrub or forest. Farmland-forest edge had a negative effect, namely the activity of red deer mainly were in a distance range of 200-680 m from forest interior to the edge, and little in the edge or farmland.(2) Red deer had a much higher use of forest-shrub edge (Hi=0.332) than farmland-forest edge (Hi=0.032), due to high forage abundance an coverage of forest-shrub edge.(3) By the comparison of effects between forest-shrub and farmland-forest edge, the habitat factors of forest-shrub edge that had a positive edge effect on activity, population number and distribution of red deer were shrub coverage and arbor crown density to the edge, not arbor density and forage abundance. While the habitat factors of farmland-forest edge that had a negative edge effect were nearby human disturbance activity and foraging sites of red deer were mainly located the distance of 600- 800 m from forest interior to farmland.