Krumme Summer School 2006 EFU - Ecological Functional Units: A Basis for Sustainable Development Planning Klaus Krumme, M.Sc. Sustainable Development Group University of Duisburg-Essen E-mail: klaus.krumme@uni-essen.de Abstract Ecological Functional Unit (EFU) approach to sustainable development planning differs from the conventional approaches related to development planning in that it attempts to base the use of natural resources, be it conservation or economic development or others, on the ecosystem s natural functioning, itself determined by the ecological key processes and structures of the particular ecosystems and the variety of interconnections between them. With such an approach clusters of landscape elements on various spatial scales can be accessed and evaluated to assess their functions, capacities and limitations for development. Key Words Ecological Functional Units (EFU), Landscape Ecology, Landscape Analysis, Homogeneity, Heterogeneity, Sustainable Development, Integrating Factors, Pronounced Processing Zones (PPZ), Ecological Clustering, Natural Resource Management Introduction To base management and conservation of natural resources on the knowledge of the systems identifiable and definable dynamic and self sustaining landscape FWU, Vol. 5, Participatory Watershed Management Plan 17
Summer School 2006 Krumme discrete units, would a great advantage over many other state of the art methods. It would provide the planner and the manager with a definable element of the landscape, whose internal interacting processes can concretely be studied. Impacts of any activity on such a mini landscape element are easily identified thus making such assessments as ecological risk assessment (ERA) more effective. We term such a unit in the landscape or ecosystem an Ecological Functional Unit (EFU). The author recommends that the EFU be treated as the smallest mapable landscape functional unit. This way the EFU can serve as the basis for an integrated planning and management of landscapes and the resources therein. Definition of EFU In his search to find out the functional components of a complex entity referred to as a landscape, a German biologically oriented geographer, Carl TROLL in 1950, coined up the term ecotope (NAVEH & LIEBERMAN 1984). He then went ahead to hypothesize that a landscape is composed of landscape cells or tiles which are homogeneous with regard to abiotic factors: physical and chemical properties of a particular substrate such as porosity, ph, texture and mineral contents. Such small cells are known as physiotopes. When colonised and transformed by organisms, the physiotope site, via biotic and abiotic interactions, is transformed into a mini holistic land unit characterized by homogeneity of at least one ecological land attribute such as geological parent material, vegetation, soils, water, climate etc. and non-excessive variations of the other attributes present (NAVEH & LIEBERMAN 1984). An ecotope thus displays such microecosystemic functions as succession in a biological community, establishment of special and temporal micro-climates, building up of niches, energy flow and nutrient circulation. When definable elements in a landscape are functionally linked together and forming a unique pattern of spatial relationship, they build a cluster of landscape elements forming a landscape unit with peculiar character and function that differs from other units. We describe the connecting factors of different landscape 18 FWU, Vol. 5, Participatory Watershed Management Plan
Krumme Summer School 2006 elements as integrating factors. We define the landscape unit so formed as an Ecological Functional Unit (EFU). The land attributes that are influencing the interconnection and ecological integration of landscape elements are to a large extent the land form and geology (which influences meso-scale hydrology, particularly drainage patterns), local climate regime, or transport of abiotic or biotic materials and energy etc. that take place in distinctive cut outs of the landscape to be described as ecological process zones. It is important to stress that the character and functionality of the ecological functional unit is not a sum of the ecotopes composing it. The interactions between the physical and biological factors of the individual ecotopes with each other and with the new topography created through the integrating factor(s) do create a whole new and unique dimension of characteristics that are unique to that particular EFU and differs from those of the individual ecotopes or those of the neighbouring EFU s. Different EFU s will differ in their structure (ecotope composition) and functional processes (integrating factors). The Importance of EFU for Development Planning From the above explanations, it can be concluded that a particular ecotope in one part of the landscape plays a completely different role from another ecotope (of the same type) in another part of the same landscape, because of its interrelationships with the surrounding landscape. It is therefore advisable not to base any judgments of potential impact from any activity on the assessments of one particular ecotope without establishing the linkages between that ecotope and others with which it is connected. Usually an activity taking place on one ecotope has direct or indirect impacts on the other ecotopes with which it forms the EFU. Likewise since the functioning and quality of the EFU is determined by the cumulative quality and cumulative functioning of individual ecotopes, performance and quality of the entire EFU is likely to be affected by any activity on one or more ecotopes composing it. FWU, Vol. 5, Participatory Watershed Management Plan 19
Summer School 2006 Krumme The knowledge of the EFU in the landscape therefore becomes extremely important in guiding the decisions for management, extents and impacts of assessment and monitoring procedures among others. The clustering of functional landscape units is therefore a more realistic means of understanding the ecosystems than the use of their visual appearance and structural homogeneity, as is often the case in traditional landscape planning approaches (see MARTINEZ-FALERO & GONZALEZ-ALONSO 1995). Structural homogeneity is an aspect of a mere human visual perspective. In principle, the pattern of functional landscape units exists on every level of landscape hierarchy, not only on the site level that is target of decisions of for example management measures for the usage of water resources, vegetation or geo-resources in a demarcated water catchment (sub-regional level). Landscape ecology recognizes the existence of clusters of sites, ecosystems or landscapes at local, regional or global scales. Deriving from our definition for the EFU, it may be possible to argue that landscapes do not only have functional and structural order but be also spatially structured and ordered in a hierarchy of functions at various levels. To be successful, ecological planning must respond to the functional order of the landscape and identify those landscape units that represent the functional clusters at different scales (Figure 1). For the explained background this approach in planning has an advantage of maintain ecosystem functioning and health, which are ultimate goals of sustainable development, unlike most of the current conservation and development planning approaches, which are oriented on static goals of resource availability, accessibility of resources, species or structural richness in the nature, and thus ignoring the functional processes necessary for developing the patterns they want to conserve or be a basis for economic development (see also BALMFORD & MACE & GINSBERG 1998).The EFU approach can be seen as a new attempt to provide the process that would contribute to the solution of this problem and numerous other conflicts, when landscape analysis is an ultimate necessity for land use planning. We refer to the planning 20 FWU, Vol. 5, Participatory Watershed Management Plan
Krumme Summer School 2006 process of recognizing the functional units at different regional landscape scales as the ecological functional clustering. Bioregions In this light we see the so called bioregions (MILLER 1996, BRUNCKHORST 1995, 2000, AJATHI & KRUMME 2002, KRUMME & AJATHI 2006) as functional clusters of ecosystems and broader landscape units interacting with human cultural subsystems. The most determining force in forming a bioregion is thus the geomorphology as the main underlying driver for site conditions of water, temperature or nutrients, in forming ecological gradients and at least a main natural determinant for human settlement and culture. Thus the bioregion is a natural comprehensive cluster of multiple ecological, socio-cultural and economic features and the frame in which all these phenomena should interact in a sustainable manner. The planning process for a sustainable development should thus have the bioregion as its central management unit. Water Catchment Areas For the necessary downscaling and the provision of concrete action plans the introduction of sub-regional management referring to water catchments appears as a suitable and strategically coherent means. Water catchments that are naturally characterised by its watersheds as functional entities could be integrated into such a hierarchical approach to development planning as another level of ecological functional clustering that is consistent with the principles explained earlier. Conservation Areas Another practise oriented level of planning can be the establishment of protected areas for the background of conserving ecological processes with an ultimate function for the regional ecological sustainability. In a bioregional context therefore, a protected area should be planned as a priority cluster of key ecological functions. The protected areas serve as management units for the key processing areas, which provide important and essential ecological services to the respective bioregions and at the same time, serve as the ecological architecture of a bioregion. FWU, Vol. 5, Participatory Watershed Management Plan 21
Summer School 2006 Krumme ECOLOGICAL FUNCTIONAL CLUSTERS IN DIFFERENT PLANNING SCALES Bioregion as comprehensive functional cluster of multiple ecological, socio-cultural, and economic features Water Catchment Areas (subregional) + X EFU x n Ecotopes Figure 1: An Association of Functional Clusters in Different Landscape Scales The Procedure of Functional Landscape Analysis Being a new idea, the EFU concept in landscape planning has no practical field application experience as yet. This paper only provides a theoretical process for the identification of the ecological functional units in the landscape. The author hopes the application of these ideas in the future will produce concrete results to a description of an innovative methodology for functional landscape analysis. Delineation of EFU on the site level, or more generally different functional landscape units in different scales, starts with the consideration of the factors that are likely to determine process functioning and structure of the area targeted for planning. Assessment of those factors could be done using both the inventories of the ecological records accompanied by analysis of the maps, area photographs and satellite derived information with the help of computer technologies such as GIS (Geographical Information System) and simulation programmes. A first impression of the factors composing the landscape is made through a systematic classification of the important ecological drivers for landscape 22 FWU, Vol. 5, Participatory Watershed Management Plan
Krumme Summer School 2006 phenology and function. We classify those landscape factors in four groups namely: Limiting factors: These are the ecological factors that control the growth and succession of a plant community and that lead to a gradual change in the ecosystem. Examples are water (PAM: plant available moisture), nutrients (PAN: plant available nutrients) or climatic limits for plant or animal communities like minimum temperature or extreme heat in day rhythmic or as seasonal recurring events. Trigger factors: These are natural phenomena that usually trigger a sudden major shift or change in the ecosystem. Examples in some ecosystems are fire or flood and drought. Some of these phenomena, like fire, can also be caused by human culture (HARRIS 1980 for Savannah ecosystems). Conditioning factors: These are dominating factors in an ecosystem setting, which play important roles in determining an ecosystem, but do not limit its succession. Examples are water in a river or a lake or soil characteristics like the high nutrient volcanic ashes of the Serengeti grass plains in Tanzania. Integrating factors: An integrating factor represents the connectivity of the sub-systems of a landscape. Landscape patches, like seasonal ponds, small woodland plots or swamps, can be connected by natural corridors and pathways (e.g. through groundwater layers, linear pattern of trees and bushes or a seasonal brook or river including their riparian vegetation) inbetween a surrounding landscape matrix like a Savannah of a grassy phenology. To understand the dynamics of functions of the landscape spatial elements and over time scales, it is necessary to examine the factors of landscape carefully. Especially the role played by the integrating factor is of crucial importance in the functional analysis process. The integrating factor provides the frame on which the corresponding (connected) elements (e.g. ecotopes) in the landscape synchronously function, by determining the degree of connectivity between those ecotopes. The FWU, Vol. 5, Participatory Watershed Management Plan 23
Summer School 2006 Krumme integrating factor can in its associated elements of an EFU also represent the functions of limit to growth, trigger or general condition. An Example on Water Water is one of the determining factors in the development of a valley in a landscape where seasonal flood events are occurring. These events form the geomorphology of the valley through the erosive and abrasive force of the flooding water and the materials transported in it. For most of the year in the centre of the valley there is only a small stream, where water is the conditioning factor of an aquatic ecotope. Connected to the stream are riparian ecotopes, which are determined by plant available moisture (PAM) as a limiting factor and which is provided by the stream. On higher flood plains of the valley water is only available for a short period of the year and can here play the role of the trigger and limiting factor for the vegetation growth period. Likewise it plays the role of a trigger for multiple effects in the plant and animal community (e.g. reproduction behaviour) during the flood period. All these ecotopes are depending on one integrating factor: water. Interference in one of the ecotopes (e.g. the valley riparian ecotope) may have serious destructive consequences for the equilibrium of the whole functional unit. Given the above described landscape phenomena, the examination of functional connections between different parts of the landscape is therefore a must if realistic conclusions concerning the impacts of any activity in a landscape has to be drawn. It is evident therefore that landscape analysis on the basis of single ecotopes is likely to produce errors and incomplete information for planning purposes. During the landscape analysis and delineation of the functional landscape units process it is advisable to orientate on the following principles: Do not focus on homogeneous structures in the landscape but on the ecological processes determining and integrating these structures and the inhabiting species. Verify the effects any given landscape pattern would have on the landscape functioning before adopting it as a basis for further action. 24 FWU, Vol. 5, Participatory Watershed Management Plan
Krumme Summer School 2006 Always consider the mechanism and sources of the ecological processes in the landscape which determine other physical factors such the distribution of water, temperature and nutrient. From the background of the above EFU description, an ecological functional clustering can be determined in five major steps (see also Figure 2): Examination of the geographical distribution of water (which stands strongly connected with the nutrient distribution), the main climate factors (temperature, evapotranspiration, wind systems) and the soil parent material (geo-resources) in the planning area. Identification of the processes which drive those distributions. The landform (geomorphology) thus plays a key role, because it determines the directions and pathways of flows through slope aspect and elevation (e.g. drainage characteristics) (BELL 1998). These flows can occur either in a simple linear connection of source and storage (of e.g. nutrient or water) or as a more complicated cycle (e.g. temperature and local wind systems). By integrating the above two steps, it is possible to delineate zones in which the processes and flows are taking place. According to BELL (1998), these zones are called Pronounced Processing Zones of the landscape (PPZ) which represent the borderlines for functional landscape units. With regard to a time scale sometimes the dynamic distribution or availability of abiotic factors like water or temperature in an area triggers periodic cyclic movements (migrations) of biodiversity between different parts of a landscape. Therefore animal migrations can be an appropriate indicator of those driving processes and simplify the delineation of processing zones. In the case of a site based planning, the analysis up to this point is incomplete. This is because we do not yet know exactly the elements composing the ecological functional unit. The distribution of soilvegetation-systems of the planning area should therefore be examined to define the extent of the ecotopes. Correlating this with the afore mentioned FWU, Vol. 5, Participatory Watershed Management Plan 25
Summer School 2006 Krumme energy flows, we are finally able to characterize an EFU. This aspect is logical because the soil and vegetation pattern are a direct result of the afore analysed abiotic processes. The sequential order of these steps as shown in (Figure 2) is important. It would be an impediment to begin a functional landscape analysis with the examination of soil or vegetation, because this would be obstructing the basic processes responsible for those patterns of vegetation and soil formation. It is absolutely necessary first to focus on the ecological drivers shaping the larger landscape structure and only apply that information at a later time during the down scaling to an ecotope level. ECOLOGICAL FUNCTIONAL LANDSCAPE ANALYSIS (SITE LEVEL) water BASIC GEO MAP climat eeee eeee eeee eeee geology landform PPZ RECOGNITION GEO MAP soil PHYSIOTOPE MAP EFU DEFINITION vegetation ECOTOPE MAP Figure 2: Ecological Functional Landscape Analysis on the site level Conclusions It was shown that rather to refer to homogeneous structures in landscape mapping, it has a great advantage to assess process zones that consist of several different but ecologically connected subsystems and are forming a heterogeneous functional 26 FWU, Vol. 5, Participatory Watershed Management Plan
Krumme Summer School 2006 cluster. If this cluster is the basis for the evaluation of the geographical situation, suitability and intensity of the human interference into the natural resource base of a special area, the hereby presented theoretical approach provides the prerequisite to realistically measure the impact of these actions for the long term sustainability of the broader landscape system. Doing so natural resource use in planning areas goes a step forward to the goal of the long term stability of human used natural systems. Furthermore the described idea offers a framework for a hierarchical system of land use on different spatial levels according to the naturally given functional order of landscape ecology and with this a valuable contribution to sustainable development planning. References AJATHI, H.M. & KRUMME, K. (2002): Ecosystem based Conservation Strategy for Protected Areas in Savannas - with special Reference to East Africa (Joint M.Sc. Thesis). University of Duisburg-Essen, Miless Electronic Library Essen: http://miless.uni-duisburg-essen.de/servlets/documentservlet?id=11932 BALMFORD A., MACE, G.M. & GINSBERG J. (1998): Conservation in a Changing World. Cambridge University Press, Cambridge. BELL, S. (1998): Landscape : patterns, perception, process. London. BRUNCKHORST, D.J. (1995): Sustaining Nature and Society - A Bioregional Approach. In: Inhabit No. 3, pp 5-9. BRUNCKHORST, D.J. (2000): Bioregional Planning: Resource Management Beyond the New Millennium. Harwood Academic Publishers: Sydney, Australia. KRUMME, K.&AJATHI, H.M. (2006): Learning Bioregions Concrete Visions for Sustainability, First German Conference on Sustainability Research, TuTech, 24 th of March 2006, Hamburg. MARTINEZ-FALERO, E.&GONZALEZ-ALONZO, S. (1995): Quantitative Techniques in Landscape Planning. Lewis Publishers, CRC Press, Florida. FWU, Vol. 5, Participatory Watershed Management Plan 27
Summer School 2006 Krumme MILLER, K. (1996): Balancing the Scales. Guidelines for Increasing Biodiversity s Chances through Bio-Regional Management. World Resources Management. Washington, D.C., U.S.A. NAVEH &LIEBERMANN (1984): Landscape Ecology. Cambridge University Press, Cambridge. SMITH, R.D. & MALTIBY, E. (2001): Using the Ecosystem Approach to implement the CBD (Global Synthesis Report). University of London, London. 28 FWU, Vol. 5, Participatory Watershed Management Plan