基于多维超体积生态位的高标准生态农田建设分区方法

Method for zoning high-standard ecological farmland construction using multi-dimensional super-volume ecological niche

明晰高标准生态农田建设选址及提升方向是发挥高标准农田投资效益,提升高标准农田抗灾减灾能力的技术关键。该研究基于多维超体积生态位的理论方法,从土壤条件、立地条件、空间稳定性、景观格局、生态约束等5个维度构建了高标准生态农田建设适宜性评价体系,通过比较各因素的现实生态位与理想生态位,建立障碍度与生态位耦合的障碍因子诊断模型,结合适宜性-障碍度-改造难度的组合结果,按照“由优到劣,先易后难”的顺序进行高标准生态农田建设优先度分区,并对河北省保定市326460万个耕地斑块进行了定量化评估。结果表明:1)保定市高标准生态农田建设适宜性整体中等偏低,中等适宜的耕地面积最多,勉强适宜的耕地面积最少。2)保定市耕地的土壤条件与生态约束对其建设发展的障碍度较高。土壤条件维度下的主要障碍因子为有机质含量、土壤pH值及土层厚度;地下水埋深与地下水补给量是生态约束维度的主要障碍因子。3)将保定市高标准生态农田建设划分为生产优先建设区、生产次优先建设区、“生产-生态”协同建设区、后备建设区及生态保育区。其中生产优先建设区所占比例最大,面积约为20.99万hm^(2),建设适宜性高,主要障碍因子改造难度小,提升潜力大,稍加改造即可达到区域最优水平。上述方法能够有效用于区域高标准生态农田建设适宜性评价,研究结果可为国家实施的高标准生态农田建设选址工作提供科学的决策依据。

Site selection and upgrading direction can greatly contribute to the high-standard ecological farmland construction,particularly for the high investment benefits and disasters resistance.In this study,an evaluation system was constructed for the high-standard ecological farmland using the multi-dimensional super-volume ecological niche from five dimensions,including the soil conditions,standing conditions,spatial stability,landscape pattern,and ecological constraints.A quantitative assessment was also performed on the 326460 cultivated land patches in Baoding City,Hebei Province of China.The results show that:1)The better performance was achieved in the high-standard ecological farmland construction suitability evaluation index system in the city from the aspects of soil conditions,standing conditions,spatial stability,landscape pattern,and ecological constraints.The construction suitability was also comprehensively evaluated to better reflect the spatial distribution characteristics of cultivated land plots.There was the medium construction suitability of cultivated land in the study area.Among them,there was the largest area(about 194200 hm^(2))of arable land that was barely suitable for construction,accounting for about 27.93%of the total cultivated land in the city,followed by medium suitable cultivated land with an area of 180000 hm^(2),accounting for about 25.90%of the total.2)There was no area of soil condition obstacles≤0.5 for the construction of high-standard farmland,indicating that the cultivated land was greatly affected by the soil conditions.Specifically,the areas with the obstacles of 0.51-0.70,0.71-0.80,and 0.81-1.00 accounted for 17.31%,38.51%,and 44.17%of the total area,respectively.3)The study area was divided into the high-standard ecological farmland production priority construction area,production sub-priority construction area,"production-ecology"collaborative construction area,reserve construction area,and ecological conservation area,according to the combination of restriction factors and construction suitability of different transformation difficulties under ecological constraints.The cultivated land area of the production priority construction area was 209900 hm^(2),indicating the high construction suitability.Nevertheless,the main obstacle factors were difficult to transform,while the regional optimal level was reached with a little transformation,indicating a large improvement potential.The land construction suitability of the sub-priority production construction area is relatively high.The“production-ecology”cultivated land area of the collaborative construction area was about 86400 hm^(2),which was affected by the obstacle factors of the ecological constraint dimension.The cultivated land area of the reserve construction area was about 204700 hm^(2),mainly distributed in the hilly areas,such as Yi County,Quyang County,and Fuping County.The cultivated land area of the ecological conservation area was about 56200 hm^(2),where the more effective paid and orderly exit mechanism should be explored or regulated as a reserve resource.The farmland protection strategy should also be implemented to fully meet the needs of reasonable land use.