山东省极端气候和人类活动对不同植被类型NDVI的影响

Effects of extreme climate and human activities on NDVI(normalized difference vegetation index)of different vegetation types in Shandong Province

山东省作为我国华东典型的沿海地区,气候多变,人口密集,开展极端气候和人类活动对植被的影响对沿海地区生态环境稳定具有重要意义。基于BRT模型、多元线性回归方程和残差分析等方法研究了不同植被在极端气候和人类活动干扰下的生长状况。结果显示:(1)2000—2020年山东省全区NDVI(归一化植被指数)呈增长趋势且具有正持续性(H>0.5)。空间上,鲁西北和鲁西南植被生长状况较好且得到了显著改善,而北部黄河三角洲和莱州湾地区植被覆盖低且得到了显著退化。不同植被类型中草丛植被得到了显著改善(P<0.05),而草甸植被退化较为严重;(2)近年来夜间温度(TMINmean、TN90p)的上升,连续干旱日数CDD和瞬时强降雨RX1d的增加有利于研究区植被的增长,而高温极值TXx的上升以及霜冻日数FDO的减少抑制了植被的增长;(3)对于不同植被类型,整体上受到极端气温的影响较大,且对栽培植物和针叶林的解释度更高,同一指标对不同植被类型的影响程度和正负效应存在较大的差异;(4)人类活动在全区植被变化中占主导地位且起到了显著改善作用(P<0.05)。不同植被类型中草甸受到人类活动的干扰最为明显,而针叶林则更多受到气候变化的影响。研究结果能对山东省植被未来的管理和规划提供科学支撑,同时对沿海地区生态环境调控和可持续发展起到了促进作用。

Shandong Province,as a typical coastal area in East China,has a changeable climate and a dense population.The impact of extreme climate and human activities on vegetation is of great significance to the stability of the coastal ecological environment.Based on BRT model,multiple linear regression equation and residual analysis,this paper studies the growth of different vegetation under extreme climate and human activities.The results showed:(1)From 2000 to 2020,NDVI(normalized difference vegetation index)in the whole region of Shandong Province showed an increasing trend and had a positive sustainability(H>0.5).In space,the vegetation growth in the northwest and southwest of Shandong was good and had been significantly improved,while the vegetation coverage in the northern Yellow River Delta and Laizhou Bay was low and had been significantly degraded.Grass vegetation in different vegetation types had been significantly improved(P<0.05),while meadow vegetation degradation was more serious;(2)In recent years,the increase of night time temperature TMINmean(mean daily minimum temperature)and TN90p(number of warm nights),the increase of continuous dry days CDD and instantaneous heavy rainfall RX1d(1-day maximum precipitation)were conducive to the growth of vegetation in the study area,while the increase of high temperature extreme value TXx and the decrease of frost days FDO inhibited the growth of vegetation;(3)For different vegetation types,the overall impact of extreme temperature was greater,and the interpretation degree of cultivated plants and coniferous forests was higher.The impact degree and positive and negative effects of the same index on different vegetation types were significantly different;(4)Human activities played a leading role in the vegetation change in the whole region and played a significant role in improving it(P<0.05).Among the different vegetation types,meadow vegetation was most affected by human activities,while coniferous forest was more affected by climate change.The research results can provide scientific support for the future management and planning of vegetation in Shandong Province,and promote the regulation and sustainable development of ecological environment in coastal areas.