紫金山风景林保护区景观格局变化研究

根据紫金山 1 975、1 988、2 0 0 2三个年度的森林二类调查资料 ,在ARCGIS支持下 ,对紫金山风景林保护区景观格局动态进行了研究。结果表明 ,近 30年来 ,保护区植被格局发生了显著变化 ,总体表现为针叶林向针阔混交林 ,进而向落叶阔叶林的演替。期间 ,针叶林占保护区的面积比例由 38 9%下降为 9 7% ,阔叶林则由 1 2 0 %上升至 4 8 6 %。各景观要素中转移为其它类型概率较小的是水体、苗圃 ,而最高的是未成林地 ,接近 1 0 0 %的转移。在保护区中最易发生变化的地类主要分布在人为干扰比较强烈或者人为活动较少而自然条件较好的区域。1 975～ 2 0 0 2年 ,保护区的景观多样性指数由 1 5 74下降至 1 4 6 2 ,而优势度由 0 6 30升高至0 735 ,景观破碎度略有增加 (0 781～ 0 795 ) ,森林覆盖率从 1 96 3年的 5 1 2 %上升到 2 0 0 2年的 70 2 % ,景观总形状系数则相对稳定 ,但各类景观要素有不同的变化规律。其中针叶林随着嵌块平均面积的减小 ,破碎度的不断增加 ,形状系数持续变小 ,而阔叶林则嵌块体平均面积不断增加 ,破碎度减少 ,形状系数持续增加。据Malkov链模型预测 ,至 2 0 1 6年 ,阔叶林面积将达保护区总面积的 5 5 2 3% ,森林覆被率将上升至 74 0 9%。

Changes of the landscape pattern in Zijin Mountain Amenity Forest Reserve

Based on the second class information of forest from investigation in 1975,1988,and 2002,we studied the dynamics of landscape patterns in Zijin Mountain Amenity Forest Reserve.The results showed that in the past 30 years,the vegetation had changed significantly,and coniferous forest which was dominant in 1975 was substituted by the mixed broadleaf coniferous forest,and then transferred to deciduous broad leaf forest or mixed deciduous and evergreen broadleaf forest.In the process,the percentage of coniferous forest in the reserve area dropped from 38.9% to 9.7%,while broad leaved forest rose from 12 0% to 49 2%.Of all the landscape elements,water area and nursery had less transformation probability to other types,while non woodland transformed with a 100% probability.The most changeable patches are almost all distributed in the region with strong human activities, or with less human disturbance but better natural conditions.In the period,the landscape diversity dropped from 1 574 to 1 462,while the landscape dominance increased from 0 630 to 0 735;degree of fragmentation raised from 0 781 to 0 795;and vegetation coverage continuously grew from 51 2% in 1963 to 70 2% in 2002.The landscape shape coefficient kept steadily.But different landscape elements had different change trends.For the coniferous forest,with the average area of the patches decreasing,the fragmentation raised,while the shape coefficient declined.But for deciduous forest,the average area of the patches and shape coefficients increased and the fragmentation decreased.According to the Malkov model,the percentage of deciduous forest area will increase continuously to 55 23,and the forest coverage will grow to 74 09% in year 2016.