中国南方古梯田的分布与景观结构特征

Distribution and landscape structures of ancient terraces in southern China

以中国南方典型古梯田为研究对象,运用景观生态学原理、ArcGIS技术和方法,对其分布和景观特征进行分析。结果表明:1)中国南方古梯田主要分布在云南省、四川省、贵州省、广西壮族自治区、湖南省、江西省、福建省和浙江省,总面积超过2600 km 2;比较著名的有哈尼梯田、龙脊梯田、紫鹊界梯田、上堡梯田、云和梯田等;2)中国南方古梯田位于E 101°48′~119°29′、N 22°33′~29°46′之间的亚热带山区和丘陵地区,海拔范围约为150~3000 m,在6°~25°坡度区间的阳坡分布最多,半阳坡和半阴坡次之,阴坡分布最少;3)中国南方古梯田生态系统主要由林地和耕地(梯田)组成,林地所占面积比例为53.77%~86.36%,耕地(梯田)所占面积比例为6.59%~35.66%,林田面积比例为1.62~13.42,森林为梯田涵养了水源;4)中国南方古梯田的垂直景观结构为从山顶到河谷以“四素同构”与“多素同构”为主,其中“四素同构”的景观结构特征为:森林村庄梯田河流;“多素同构”的景观结构特征为:森林村庄梯田城镇河流。独特的景观结构形成从山顶森林到山腰村寨、梯田到河谷的自流灌溉系统和借助灌溉渠系的梯田养分输入系统。研究结果对现代梯田的建设具有指导意义。

[Background]Terracing is an important measure for soil and water conservation,in the southern region of China,the ancient terraces have become a model for the harmonious development of human activities and the natural landscape structure of the mountains during the development of farming culture for hundreds and thousands of years.And the water and soil conservation role of terraces and the sustainable development of ecosystems are of great significance to maintain the sustainable development of mountain agriculture in China.[Methods]Taking 12 typical ancient terraces in southern China as the research objects,we combined Landsat 8 OLI image data and DEM data,visually interpreted and extracted the landscape elevation data of each ancient terrace and the slope and slope direction data of the terrace subsystem using ArcGIS technology,and calculated the landscape pattern index of each ancient terrace using the principle of landscape ecology and Fragstats software to analyze its distribution characteristics and landscape features.[Results]1)The ancient terraces in southern China are mainly located in Yunnan province,Sichuan province,Guizhou province,Guangxi Zhuang autonomous region,Hunan province,Jiangxi province,Fujian province and Zhejiang province,with a total area of over 2600 km 2.Representative famous terraces include:Hani Terraces,Longji Terraces,Ziquejie Terraces,Shangbao Terraces,Yunhe Terraces,etc.2)The ancient terraces in southern China are located in the subtropical mountainous and hilly areas between E 101°48′-119°29′and N 22°33′-29°46′.The altitude range is about 150-3000 m.Moreover,they are most distributed on the sunny slope,second on the semi-sunny slope and semi-shady slope,and least on the shady slopein the range of 6°-25°.3)The ancient terraced ecosystems in southern China mainly consist of forest land and cultivated land(terraces),with the percentage of area occupied by forest land from 53.77%to 86.36%and the percentage of area occupied by cultivated land(terraces)from 6.59%to 35.66,and the ratio of forest to field area is 1.62-13.42.Forests provide a constant source of water for the terraces.4)The vertical landscape structure of ancient terraces in southern China is dominated by“four-elements isomorphism”and“multi-elements isomorphism”from the mountain top to the river valley,in which the landscape structure of“four-elements isomorphism”is characterized as follows:Forest-village-terraces-river.The landscape structure of“multi-elements isomorphism”is characterized as:Forest-village-terraces-town-river.The unique landscape structure has formed the self-flow irrigation system from the forest at the top of the mountain to the village on the mountainside and the terraces to the river valley and the nutrient input system of the terraces with the help of the irrigation canal system,which guarantees the longevity of the terraces.[Conclusions]The study of ancient terraces in southern China clarifies their distribution,landscape structure and common features of their formation.It provides a basis for improving the soil and water conservation function of terraces,promoting the sustainable development of mountain agriculture and the construction of modern terraces.