CAJ | 학술논문

为了分析中国农牧交错带植被典型物候期(生长开始日期,生长结束日期和生长季长度)的变化趋势,利用2001-2010年 SPOT-VGT NDVI(SPOT-VEGETATION normalized differential vegetation index)数据,基于 Savitzky— Golay滤波和动态阈值法,提取了中国北方农牧交错带植被物候期,探讨研究区植被物候期的空间差异和时间变化.研究表明,农牧交错带植被的生长季一般从4月中旬到5月下旬开始,9月下旬至10月下旬结束;从西南部到东北部,植被物候表现出明显的空间差异;农田植被物候期与自然植被略有不同;对研究区10 a 物候期线性拟合,得出研究区大部分植被覆盖区域生长季开始日期呈现提前趋势,提前日期大约为1~10 d 左右;除部分地区外,2001-2010年农牧交错带植被生长季结束日期没有明显变化趋势;10 a 间研究区大部分草地生长季延长,也有一部分地区的生长季出现缩短趋势.研究提取结果与已有的相关研究结果较为一致,可为农牧交错带生态环境评价和保护提供一定的参考.
위료분석중국농목교착대식피전형물후기(생장개시일기,생장결속일기화생장계장도)적변화추세,이용2001-2010년 SPOT-VGT NDVI(SPOT-VEGETATION normalized differential vegetation index)수거,기우 Savitzky— Golay려파화동태역치법,제취료중국북방농목교착대식피물후기,탐토연구구식피물후기적공간차이화시간변화.연구표명,농목교착대식피적생장계일반종4월중순도5월하순개시,9월하순지10월하순결속;종서남부도동북부,식피물후표현출명현적공간차이;농전식피물후기여자연식피략유불동;대연구구10 a 물후기선성의합,득출연구구대부분식피복개구역생장계개시일기정현제전추세,제전일기대약위1~10 d 좌우;제부분지구외,2001-2010년농목교착대식피생장계결속일기몰유명현변화추세;10 a 간연구구대부분초지생장계연장,야유일부분지구적생장계출현축단추세.연구제취결과여이유적상관연구결과교위일치,가위농목교착대생태배경평개화보호제공일정적삼고.
Vegetation phenology dynamics reflect the response of biosphere to global climate change and terrestrial hydrological cycle mechanism changes. It is connected well to ecosystem primary productivity of terrestrial and carbon cycle. As the best indicator in monitoring the influence of climate on vegetation, plant phenology has become the key point of global change research. The transition zone between cropping area and nomadic area is sensitive to climate change, thus the changes of vegetation phenology in this area has become an essential issue. Based on the Savitzky-Golay filtering and dynamic threshold method, the spatial-temporal pattern of vegetation phenology in farming-pastoral zone in Northern China was analyzed using SPOT-VGT NDVI data from 2001 to 2010. The results showed that vegetation phenology in the study area generally started from mid-April to late May, and ended in late September to late October. The spatial patterns of vegetation phenology were significantly different in study region. Growth stages of vegetation phenology in the southwest started earlier than the northeast, while ended later. Therefore, length of vegetation growth season in the southwest was longer than those in the northeast. However, greenup dates of vegetation in the Yellow River coast were earlier than vegetation in the same latitudinal zone because of the effect of water. Compared with natural vegetation, growth stages of crops were slightly different due to management. To study the trends of inter-annual variations of the SOS and EOS over the study area, linear regressions are fitted to the start of greening and end of season dates for each pixel of the study area from 2001 to 2010. The results showed that start dates of growth stages were advanced approximately 1-10 days in most study areas for all years. However, the end dates of vegetation growing seasons had no significant changes from 2001 to 2010, except for partial areas. In some regions, the length of seasons (LOS) extended, while decreased in other areas. The phenology of vegetation extracted using SPOT-VGT NDVI datasets in this paper was generally concordant with many reported researches. This paper can provide a reference for the evaluation and protection of ecological environment in farming-pastoral zone.