Research content of landscape ecology

Landscape ecology is a comprehensive subject that studies the interaction between landscape and ecology, and the composition and spatial layout of landscape units. It includes both "horizontal relationship" and "vertical relationship", that is, the relationship between spatial units. It can also be said that the research contents of landscape ecology include: the function, structure, level and change of landscape, the planning, construction, supervision and early warning of landscape, etc.

(A) landscape structure, function and landscape changes

Landscape structure refers to the type, diversity, quantitative composition, spatial and hierarchical relationship of landscape elements and their influencing factors, including patches, corridors and substrates, as well as the type, quantitative composition, spatial configuration, diversity, fragmentation, connectivity and dominance of elements. Landscape function refers to the supporting role that landscape can provide for the survival and development of its own internal and other related life systems through its ecological process. Landscape change, also known as landscape dynamics, is to study the process, characteristics and laws of landscape change with time under the action of different driving factors, including landscape change standards, stability and its measurement, driving forces and spatial pattern.

(2) Landscape ecological planning

Landscape ecological planning is to put forward the best utilization scheme of landscape through the analysis and evaluation of landscape characteristics. Its goal is to coordinate the ecological characteristics and internal activities of the landscape in time and space, so as to realize the rational utilization of the landscape, protect the environment and develop production, and reasonably handle the dialectical relationship between production and ecology, resource development and protection, economic development and environmental quality, development speed, scale, capacity and environmental carrying capacity.

Although land reclamation after the disaster has improved the land use structure and increased the land use value, the planning of land landscape ecology can not be ignored. The regional landscape destroyed by natural disasters is often seriously fragmented. Land landscape ecological planning is to use the principle of landscape ecology, combined with the landscape ecosystem of the disaster area, to plan the landscape structure closer to the local natural environment. In the ecological planning of land use landscape, there are some typical planning modes:

The combination of (1) concentration and dispersed phase. It is a landscape ecological planning model put forward by American landscape ecologist Forman( 1986) according to the ecological space theory, which is the main theoretical basis for optimizing the spatial pattern of land use and is considered as the best landscape pattern in ecology. This model emphasizes the centralized use of land to maintain the integrity of large natural vegetation patches and give full play to their ecological functions; In the process of designing and guiding natural patches, they enter agricultural farming or building areas controlled by human activities in the form of small patches or corridors. At the same time, within the scope of human activities, some artificial patches are designed around corridors and natural vegetation patches, such as residential areas, industrial and agricultural patches and so on.

(2) Ecological network model. Mainly from the island biogeography theory of Mac Arthur and Wilson( 1967) and its application on land. The occurrence of natural disasters has intensified the fragmentation of natural habitats and formed many natural habitat patches of different sizes and degrees. With the increasing isolation and fragmentation of natural habitats, some animal and plant populations have become extinct. Ecological network mode is to connect various separated ecosystems through ecological network to solve the problem of fragmentation and isolation of natural habitats. The ecological network model consists of three parts: natural development area, connection area and core area. Natural development zones aim to protect natural landscapes and natural resources. The connecting zone maintains and promotes species migration between and within the core areas, while the core areas are located in protected areas with high ecological value.

(3) the "thousand-layer cake" model. It was put forward by Mc Harg I.L.( 1967) according to the suitability analysis. The main route of the planning model of "Melaleuca Cake" is to determine the quality evaluation index and weight value according to the characteristics of the influencing factors (such as topography, hydrology, climate, animal and plant conditions, living conditions, traffic conditions, etc.) on the basis of studying the influencing factors and determining their main functions, and then map and superimpose the single factors in turn, and make a comparative analysis by using the geoscience information system, and finally formulate a planning scheme suitable for the local agricultural landscape. Its basic planning framework is shown in Figure 2-2.

Figure 2-2 Planning Framework of "Melaleuca Cake" Model (According to Yu et al., 2005)

(4) Regional ecosystem model. The famous British ecologist A.G.Tansley put forward the concept of "ecosystem" in 1935. According to this theory, Odem (1969) proposed a regional ecosystem planning model. The main manifestations of ecosystem are energy flow and material circulation, including: ① the quantity, species and spatial distribution of organisms in a certain area; ② Effects of light, temperature, humidity and soil on biological growth and development; ③ The content and distribution of water, air, minerals and other nonliving substances; (4) The way in which matter and energy circulate in the ecosystem; ⑤ The regulation of environment on biology. The adjustment of soil nutrients, the improvement and optimal allocation of regional species and the spatial distribution of biological populations are the key points of regional ecosystem model planning. Under the premise of not destroying local cultural characteristics and promoting social and economic development, the purpose of improving soil can be achieved by appropriately changing the planting methods and habits in the region, so that the destroyed ecosystem can be restored and the regional ecological environment can achieve sustainable development.

(3) Landscape ecological protection and management

Landscape ecology should not only study the regular characteristics of the occurrence, development and succession of landscape ecosystem, but also use ecological principles and methods to explore ways and measures for rational utilization, protection and management of landscape. Through scientific experiments and mathematical models, the optimal combination, management measures and constraints of landscape ecosystem are studied. Multi-level utilization of ecological engineering can effectively improve the intensity of plant photosynthesis, maximize the use of primary heterotrophs, and maximize the economic benefits of biological products with different nutritional levels. Establish cultural landscape and natural landscape protection areas, protect and manage resources and environment, protect ecological processes and life support systems, protect genetic diversity, protect existing biological species, and continuously enhance the functions of landscape ecosystems.

(D) Landscape ecological monitoring and early warning

Landscape ecological monitoring and early warning is based on the classification and evaluation of landscape ecology, monitoring the changes of ecological environment under the intervention and influence of human activities, and predicting the possible changes in the structure, function and environment of landscape ecosystem. The task of landscape ecological monitoring is mainly to continuously monitor the status of components such as nature, biosphere and artificial ecosystem, determine the changes of these components, and find out the role of human activities in these changes. Landscape ecological monitoring is to establish monitoring stations in representative and typical landscape ecosystems, collect information and data, establish and improve ecological databases, dynamically monitor the changing trends of ecosystems and species, and provide favorable scientific basis for decision-making departments to formulate policies and measures for rational utilization of natural resources and protection of ecological environment.