The role of landscape ecology in biodiversity protection

The role of landscape ecology in biodiversity protection

Biodiversity is the material basis of human existence. With the development of human beings, biodiversity has been seriously threatened and attracted worldwide attention. Let's take a look at the role of landscape ecology in biodiversity protection.

introduce

Biodiversity is the result of the development and evolution of life on earth after billions of years. It is the precious wealth of the world, the material basis for human survival and the biosphere environment for human survival. With the rapid growth of population and the intensification of human economic activities, especially the blind demand for natural biological resources, biodiversity, as the most important foundation of human survival, has been seriously threatened. The problem of biodiversity is no longer just a concern of scientists, but has aroused widespread concern of the international community and many governments.

Biodiversity is reflected in all organizational levels of life systems, from genes to ecosystems. Diversity at all organizational levels is very important. Different levels of biodiversity are closely related and inseparable.

Landscape ecology is a new and rapidly developing discipline. Compared with traditional ecological research, landscape ecology clearly emphasizes the importance of spatial heterogeneity, hierarchical structure and scale in studying ecological pattern and process, and the influence of human activities on ecosystem, especially the interaction between spatial structure and ecological process on multiple scales. As far as biodiversity protection is concerned, landscape ecology pays attention to landscape diversity and individual behavior, population, community dynamics and the role of ecosystem at different time and space scales. It is emphasized that the interaction among landscape spatial pattern, ecological process and scale is the core of landscape ecology

There are two main methods to study biodiversity. One is a "bottom-up" approach, starting from the bottom of genetic diversity and species diversity. This method emphasizes the component role of the system, which is conducive to revealing the micro-mechanism of the occurrence, maintenance and loss of biodiversity under natural conditions, but often ignores the role of external environment such as human interference. At present, human activities have a great influence on all levels of biological systems, such as populations and ecosystems, through direct or indirect influences. The loss of biodiversity and species extinction are no longer the result of natural normal evolution. Therefore, biodiversity protection should pay special attention to another "top-down" research approach, that is, taking human interference as the main factor of biodiversity loss, emphasizing the influence of landscape pattern changes under human interference on genetic diversity, species diversity and ecosystem diversity, and formulating corresponding biological protection strategies accordingly, which is the key research approach of landscape ecology.

Application of landscape ecology principle to biodiversity protection 1

The basic principles of landscape ecology for biodiversity protection mainly include: patch-corridor-matrix theory; Graded patch dynamics and compound population theory; Landscape heterogeneity and landscape diversity; Landscape connectivity, connectivity and penetration theory; Interference theory etc.

1. 1 patch-corridor-matrix theory

Landscape is a heterogeneous land area repeated by different ecosystems in a similar way. According to the position and form in the landscape, landscape elements can be divided into three types: patch, corridor and matrix.

1. 1. 1 patch refers to the spatial part that is different from the surrounding environment in appearance or nature, but has certain homogeneity inside. Its size, type, shape, boundary, location, quantity, dynamics and internal homogeneity have specific ecological significance for biodiversity protection.

Patch size not only affects the distribution of species and productivity, but also affects the distribution of energy and nutrients, which determines the ecological function of patches and even the whole landscape. The optimal landscape consists of several large natural vegetation patches, which are connected with many small patches scattered in the matrix to form an organic whole landscape. The influence of patch type on species dynamics is very obvious. By affecting the migration or disappearance of a specific species, it affects the population number and richness of that species in the patch, and then affects species diversity. The shape of patches is as important as the area in affecting biodiversity, and has an important impact on ecological processes and various functional flows. The shape of patches mainly affects the species diversity in patches by affecting the material and energy exchange between patches and substrates or other patches. The species diversity of circular patches is expected to be high, while long patches are easy to promote the exchange of materials, energy and organisms between patches and the surrounding environment. Generally speaking, two large natural patches are the minimum number of patches to protect a species, and 4 ~ 5 patches of the same type are ideal for maintaining the long-term health and safety of the species. In addition, the edge effect of patches is the most important reason for the ecological differences between patches of different shapes. Under the same area, the ratio of the inner area to the edge area of circular patches is larger than that of rectangular patches, and the ratio of the inner area to the edge area of slender patches is the smallest. Therefore, the shape, size, quantity and edge effect of patches should be considered comprehensively in landscape planning to obtain the best scheme.

1. 1.2 corridor refers to a narrow strip that is obviously different from the matrix. It is a landscape element with the function of channel or barrier, and it is an important bridge and link connecting patches. Corridor greatly affects the connectivity between patches and the exchange of species, nutrients, energy and genes between patches. The ecological function of the corridor depends on its structural characteristics, including width, composition, internal environment, shape, continuity and the relationship with the surrounding environment. Corridor has duality in the landscape. On the one hand, it separates different parts of the landscape and becomes two obstacles separating the landscape. On the other hand, it can be used as a channel connecting different parts of the landscape, which plays a role in traffic and protection. The important functions of corridors in biodiversity protection are as follows: ① Providing special habitats or temporary shelters for some species. ② Increase the connectivity of patches, improve the species migration rate between patches, promote the species flow and gene exchange between patches, facilitate the mating of the same species between different patches, facilitate the spatial movement of species, and increase the chances of species re-migration. At the same time, the original isolated species in the plate can survive and continue, providing a continuous habitat network for species lacking spatial diffusion ability, thus preventing inbreeding and genetic degradation of small populations. (3) Promote the growth of a certain population in the patch after extinction and the invasion of exotic populations, thus playing a positive role in maintaining the number of species and increasing the fragmentation of the landscape. The contradiction and complexity of corridor function require careful consideration in corridor design, so that the corridor has the natural background and local characteristics of the original landscape. The banded corridor is wide and contains the central internal environment with rich biological species, which resists the interference of the surrounding environment. The diversity pattern of internal and marginal species changes with the change of corridor width, which is of great significance to the design of corridors in biodiversity protection.

1. 1.3 matrix is the background of the landscape, which is the landscape element with the largest area, the best connectivity and the strongest control over the landscape. Matrix has obvious control function on the ecological processes such as material and energy flow, biological migration and foraging within and between landscape elements such as patch mosaic. Therefore, the substrate as the background plays a key role in biodiversity protection. Its main functions are: ① to provide small-scale spermatogenesis for some species; ② As a background, it controls and influences the exchange of material and energy between habitat patches, and strengthens or buffers the islanding effect of habitat patches; ③ Control the connectivity of the whole landscape, thus affecting the migration of species between patches.

1.2 patch dynamics and compound population theory

The theory of patch dynamics plays a guiding role in biodiversity protection, which emphasizes that: ① ecosystem is a hierarchical system organized by patch mosaic; ② The dynamics of ecosystem is a comprehensive reflection of individual behavior and patch interaction; (3) Non-equilibrium viewpoint is ubiquitous in the ecosystem, and non-equilibrium stochastic processes at local scale are often an integral part of system stability; ④ Compatibility and composite stability.

Compound population theory is a population patch system composed of several sub-populations that are isolated in space and interrelated in function. Compound population has two basic characteristics: one is the frequent extinction of sub-population system; Secondly, there is the communication of biological propagators between sub-populations, which makes the composite population show composite stability at the landscape level. Compound population theory provides a new idea for biodiversity protection.

1.3 landscape heterogeneity and landscape diversity

Landscape heterogeneity is the basic attribute of landscape, which contains two meanings: heterogeneity and complexity of landscape elements; Any landscape is composed of low-level heterogeneous landscapes with different structures and functions. It emphasizes the variation degree of landscape and the difference of landscape types. Some species need different living environments in their life cycle. Different species have migration and migration habits and also need different habitats. The heterogeneity of landscape provides a variety of living environments, which is conducive to the survival and continuation of species and the stability of ecosystems. The high degree of landscape heterogeneity, on the one hand, leads to the decrease of species in the mosaic and its internal environment, on the other hand, leads to the increase of marginal habitats and species, which means the decrease of rare internal species and the increase of marginal species, and at the same time improves the existence of potential total species.

Landscape diversity refers to the diversity of landscape units in structure and function, including patch diversity, type diversity and pattern diversity. Landscape diversity has an important influence on the migration, transformation and migration of matter, energy and species in the landscape. The relationship between patch diversity and biodiversity is complex, and they are not simply proportional. Pattern diversity emphasizes the diversity of spatial distribution of landscape types and the spatial and functional relationship between them, which has certain influence on various ecological processes. Therefore, special attention should be paid to the construction of key areas of biota and the optimization of landscape pattern in landscape planning.

1.4 landscape connectivity, connectivity and penetration theory

Landscape connectivity is a measure of the continuity between landscape spatial structural units and the relationship between ecological processes and functions, including structural connectivity and functional connectivity. For biological communities, when the landscape connectivity is large, biological communities are more likely to migrate, forage, exchange, reproduce and survive in the landscape, with less resistance; On the contrary, it is difficult to survive because of the great resistance to exercise. An important research field of biodiversity protection is the protection of fragmented habitats. The potential function of habitat connection, especially in promoting the movement of organisms between patches, relocation after local extinction and gene flow, has attracted extensive attention of landscape ecologists.

Landscape connectivity refers to the connection of landscape elements in spatial structure. Landscape with high connectivity is not necessarily high connectivity; For the landscape with small connectivity, the landscape connectivity is not necessarily small.

The impact of landscape connectivity on population dynamics, soil erosion process, disturbance diffusion and other ecological processes has critical threshold characteristics, which involves infiltration theory. The most prominent feature of the osmotic theory is that when the density of the medium reaches a certain critical value, the osmotic liquid can suddenly reach the other end from one end of the medium. Infiltration theory puts forward a more interesting and challenging topic for biodiversity protection.

1.5 interference and biodiversity

Interference is the main source of landscape heterogeneity, which can be divided into human interference and natural interference. It is one of the main sources of the heterogeneity of environment and resources in time and space, and it can change the quality and quantity of resources and environment, as well as the size, shape and distribution of the space occupied. The research shows that the impact of interference on biodiversity, on the one hand, improves the overall biodiversity by increasing the number of patches and community types; On the other hand, due to the decline of patch shape index and the simplification of adjacent structure between communities, biodiversity is reduced. Therefore, the impact of human interference on biodiversity is twofold. Sufflin pointed out that moderate disturbance is beneficial to improve species diversity. At present, interference is also a hot spot in landscape ecology research, which provides new ideas and ways for the protection of biodiversity.

2 Application of landscape ecology principles

Landscape ecology provides a new theoretical method for biodiversity protection. It pays more attention to the types of landscape structural units, the study of ecological flows and processes, and the protection of higher-level biological habitats. Reasonable adjustment of the existing landscape ecosystem and planning and designing new landscape patterns are effective methods to protect landscape biodiversity. At present, the application of landscape ecology principles in biodiversity protection can be summarized as: urban biodiversity protection, nature reserve biodiversity protection and scenic area biodiversity protection according to the degree of human interference.

2. 1 Biodiversity conservation in cities and nature reserves

The landscape ecological strategy of urban biodiversity protection mainly includes the following aspects: ① strengthening the construction and protection of urban landscape plates in urban planning: first, increasing the types of landscape patches; second, improving the diversity of landscape patch types and improving the spatial heterogeneity of urban gardens. ② Reasonable construction of a large area of forest patches in suburbs. Taking suburban forest patches as a supporting system to improve and maintain urban landscape can not only purify the air and provide wildlife habitat, but also provide sources for urban garden species and increase the benign ecological pool of biodiversity. ③ Strengthen the optimization of urban corridors. Urban corridors can be divided into three types: greenway, blue road and gray road. Greenway refers to the present situation of plant greening, providing habitats for living things and helping wild animals and plants migrate to urban parks in the natural environment of suburbs. Blue roads are mainly rivers and coasts in cities, and reasonable blue road planning is conducive to reducing the disaster and suddenness of floods. Gray roads refer to those artificially built streets, expressway, railways, etc. In planning and construction, we should pay attention to the organic combination of greenway, blue road and gray road to form a coordinated and mutually beneficial whole. In a word, the key to protect urban biodiversity is to establish an optimized landscape pattern and urban green ecological network system. Shelterbelt with a certain width should be built on the periphery of the city, and ecological corridor should be built between satellite towns, which will provide rich habitat resources and ecological environment for the protection of urban diversity.

At present, the research on landscape planning methods of biodiversity protection in nature reserves is becoming more and more mature. The main steps of planning include: selecting the location of nature reserves and rationally planning the area of nature reserves; According to the theory of heterogeneous population and island biogeography, the reasonable shape and number of protected areas should be designed according to local conditions; Reasonably divide the interior of protected areas; Optimize corridor design.

2.2 Biodiversity protection in scenic tourist areas

The research on biodiversity protection in scenic spots started late. The scenic spot here generally refers to the area between the urban landscape and the nature reserve, which exerts certain human interference on the natural environment background. Hu Haisheng pointed out that the protected species, communities and regions should be determined on the basis of a comprehensive investigation of scenic spots, especially on the regional scale, and the protected patches such as core protected areas, protected communities, resource-based protected areas, landscape protected areas and rare species breeding experimental areas should be scientifically and reasonably divided. From the perspective of biodiversity protection, the following factors must be considered in the corridor design of scenic spots: reducing the density of artificial corridors. One less man-made corridor is equivalent to adding an alternative way for the spatial movement of species and an insurance for their safety. Local characteristics. Native plants are planted on both sides of roads and trails that must be built in the scenic spot, which is consistent with the original matrix. The narrower the better. Try to build as few wide modern roads as possible, the width of tourist trails should be based on the principle of convenient passage, and the construction of cable cars, ropeways and air corridors in scenic spots should be strictly controlled. Blend into nature. Corridor should be integrated with natural matrix, reduce the hard boundary in the landscape, and provide opportunities for animals and plants to communicate as much as possible. For example, strewn at random street trees can provide air passages for small animals. On a large scale, a scenic spot is still just a patch of the whole earth matrix and an "island" under the rapid urbanization. Therefore, it is necessary to establish a joint network system between scenic spots: to establish interconnected corridors; Maintain landscape heterogeneity between scenic spots; Restore habitat; Straighten out the management system between scenic spots.

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