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Landscape Ecology as a Science VACLAV SKOPEK Institute of Landscape Ecology (CSAV) Formation of an adequate theoretical-methodological basis is a necessary precondition for more effective management of landscape utilization. The aim is to satisfy the ever-rising needs of society while respecting ecological limits, resource conservation needs, and the maintenance of landscape values. In this sense, a key role is played by landscape ecology. However, landscape ecology has not always been able to keep pace with the development of research objectives, and the movement from definition to evaluation and prediction seems to be rather slow. The following proposed approach should contribute to a better evaluation of landscape stability since ecological research should concentrate on system relations, linkages, and interactions. ANTHROPOLOGICAL/ECOLOGICAL LANDSCAPE SYSTEMS From the ecological viewpoint, a landscape is a system unit of mutual relationships, linkages, and interactions of particular subsys- tems or components, including the biosphere or geobiosphere, the technosphere, and the sociosphere (Figure 1). Interactions in a land- scape are mostly induced by man and can therefore be defined as an anthropological/ecological landscape system (AELS) (Hadaf i 1977). The particular linkages, relationships, and interactions within the AELS shown in Figure 1 can be attributed to an adequate ap- proach in levels of recognition. Recognition of these internal and inter-system relationships is characteristic of the classical scientific disciplines such as geology, botany, sociology, biology, and ecology. 15
16 B - biosphere T-technosphere S - sociosphere 1 - subsystem structures, internal links. relations, interactions, and functions of particular spheres 2 - subsystem structures, links, relations. interactions and functions of two neighbouring spheres 3 - all-system structures, links, relations interactions and functions of integrated landscape system ---- AELS border ^= AELS input and output research objectives FIGURE 1 Anthropoecological landscape system. However, such knowledge cannot be easily synthesized to evaluate all-system relationships, linkages, and interactions within the AELS. Biological ecology traditionally addresses the anthropogenic el- ements, and indeed all components of disturbances of the biological condition of organisms, species, communities, or ecosystems (Odum 1977, Dajoz 1972). Landscape ecological research should regard these anthropogenic elements and their components as equal in importance to other landscape elements and components. A geo-ecological site (GES), which is an element of AELS, has its specific structure and processes. At the horizontal level it is characterized by a relatively homogeneous biocenosis or technoan- thropocenosis. At the vertical level a GES occupies the soil under the influence of the rhizosphere and/or the technosphere and the part of the atmosphere which participates in the energy/material processes taking place within the particular GES. Landscape parts called subsystems are considered to be higher AELS units, and they consist of geo-ecological site complexes with single prevalent uses. These complexes of particular subsystems in turn constitute landscape systems or AELS segments. The AELS structure is shown in Figure 2. All-system linkages and relationships are based on manifestations of lower order interactions of the components and elements, their
17 structures, and processes. However, they are not merely a sum of these lower order interactions; they create a new entity. The manifestations of the all-system relationships within AELS result in the stability or non-stability of the total AELS. Therefore, the ability of AELS to maintain stability or to acquire a state of non-stability depends on the all-system relations. Stability exists at the level of particular landscape subsystems or elements. For example, at the biosphere level, there is species, population, cenosis, and ecosystem stability. Similarly, we can speak about partial stability at the level of the technosphere or the socio- sphere. Non-stability at the level of components and elements need not necessarily imply non-stability at the all-system level. Never- theless, the stability of sociosphere and technosphere components depends on the stability of biosphere components. On the other Landscape subsystems Landscape (AELS) AELS subsystems Biosphere Technospbere Sociosphere Landscape System (segment) Agricultural Subsystem Forest Subsystem lndustrial Subsystem Residential Subsystem Geoecological sites Not used Permanent grass cover not used Permanent grass cover used Temporary grass cover Arable land Water bodies Roads Other (hop-fields, vineyards etc.) Non-forest not used Non-forest used Natural forest Cultivated forest Water bodies Roads Other (forest, nursery etc.) Agricultural-industrial complex lndustrial production Water bodies Roads Other (storehouses, etc) Permanently settled Recreational Permanently settled and recreational Formerly residential and proposed residential Water bodies Roads Other (parks, orchards etc.) FIGURE 2 Anthropoecological landscape system structure.
18 hand, as mentioned above, the sociosphere and technosphere are the determining factors within the AELS. Landscape system stability is the ability to maintain an equilib- rium state when the system is not being disturbed (persistence), to resist particular load rates (resistance), or to return to the original equilibrium state after having been disturbed (resilience). The rate of landscape system disturbance depends not only on the strength of the impact but also on its character and type, as various impacts cause different responses. On the other hand, the response to the same type of influence can differ according to the type of landscape system (Hadag 1977). It has been proven that natural system stability increases with development of the basis of the system due to self-organizing pro- cesses (Miles 1979). For example, a climax community is an open system with stabilized matter and energy flows. However, this can be applied only to the natural parts of the biosphere. In the case of the AELS, only man can be regarded as the organizing element of AELS stability by making maximum use of the self-organizing biosphere components and by means of adequate energy input. Diversity is one of the most important factors determining the stability or non-stability of the elements and parts of the biosphere as well as the AELS. It is obvious that increasing diversity is related to the increase of the system stability. ENSURING ECOLOGICAL STABILITY AELS research consists mainly of studying the structural, pro- cess, and functional linkages and interactions of the biosphere, tech- nosphere, and sociosphere as well as relationships with appropriate elements in the AELS, including regularities which lead to ecological stability. On this basis it is possible to determine the rules of coex- istence of particular AELS parts and, in the case of the sociosphere and technosphere, to determine the rules of non-conflicting biosphere uses. Research and evaluation of the structure and processes in various AELS types and assessments of load impacts (sort, rate, and com- bination) enable us to determine the limits of possible load, as well as load potential related to AELS ecological stability. In evaluating AELS structure and dynamics, research concentrates on the descrip- tion of selected process regularities and on the determination or even quantification of stability functions in particular GES types. AELS
19 ecological stability parameters are determined on this basis. The concept of regional ecological stability is based on the assumption that it can be ensured by means of suitable GES combinations. The complexity and diversity of landscape systems are expressed by the spatial heterogeneity of geoecological sites and by the num- ber of interactions between them. Landscape system complexity is determined not only by the number of its structural elements but also by the number and character of the hierarchical relationships between these elements (Zonneveld 1975). The smaller and more nu- merous the geoecological sites, the larger the mutual relations that exist between them and the longer their bordering zones. Between particular geoecological sites there are transitional zones or ecotones which should be studied thoroughly. If the effects of a particular geoecological site are negative, it is possible to compensate through a more suitable transitional GES type (Skopek et al. 1987). Landscape ecological stability expressed on the basis of complex evaluations of the AELS is understood as the ability of the landscape to maintain a state of equilibrium. This ability includes both resis- tance to load and resilience in reaction to disturbances. Through detailed investigations of material, energy, and socioeconomic rela- tions or flows between geoecological sites, it may be possible to deter- mine load potential within the AELS. The recognition of the linkages and interactions which exist between AELS subsystems (i.e., inside and between particular geoecological sites and their complexes) and which determine the composition of the AELS and its holistic func- tions are crucial. Great effort has been directed to the search for optimum proportions of GES composition in accordance with land- scape ecological and economic potential in landscape management optimization. REFERENCES Dajoz, R. 1972. Precis d'Ekologie, Deuxieme Edition. Paris HadaJ, E. 1977. Complex interdisciplinary investigation of landscape. Landscape planning, 4, p. 333-348. Miles, J. 1979. Vegetation dynamics. Chapman and Hall. London. Odum, E.P. 1977. Zaklady ekologie. Academia. Prague. Skopek, V., J. Pomije, M. BartoS, D. Lhotkova. 1987. Anthropoecological evaluation of landscape system. Ecology (CSSR), 6, 2. Zonneveld, I.S. 1975. Lectures on plant ecology (vegetation science). Lecture notes N.6. ITC Enschede.
