Coastal Lagoons - Chapter 2 docx

Identification of the Lagoon Ecosystems Angheluta Vadineanu CONTENTS 2.1 Introduction 2.2 Conceptual Framework of Sustainable Use and Development 2.3 Spatio-Temporal Organization of Lagoon Ecosystems 2.3.1 Lagoon Ecotone 2.3.2 HGMU Spatio-Temporal Organization 2.3.3 Biocoenose’s Spatio-Temporal Organization 2.3.4 General Homomorph Model for Lagoons 2.4 Scientific Achievements Relevant for Sustainable Management of Lagoons and Land/Seascapes 2.5 Challenges for Ecosystem Modeling References 2.1 INTRODUCTION Lagoon ecosystems are ecotones, or transition units of landscapes and sea/waterscapes. A key aspect of lagoons is highly sensitive areas known as wetlands, the interface areas between the land and the water. According to the definition accepted by the Ramsar Convention, wetlands exist in a wide range of local ecosystems and landscapes or waterscapes distributed over continents and at the land/sea interface. They are natural, seminatural, and human- dominated ecological systems that altogether cover an average of 6% of the Earth’s land surface. 1 Wetlands are diverse in nature. They include or are part of areas such as beaches, tidal flats, lagoons, mangroves, swamps, estuaries, floodplains, marshes, fens, and bogs. 1,2 The world’s wetlands consist of about three quarters inland wetlands and one quarter coastal wetlands. Palustrine and estuarine wetlands, which include lagoons, account for most of them. 1 Exponential increase in human population and the corresponding demand for food and energy resources as well as for space and transport have in the last century stimulated the promotion of economic growth driven by the principles of neoclassical economy. Current philosophy has promoted, and unfortunately 2 L1686_C02.fm Page 7 Monday, November 1, 2004 3:28 PM © 2005 by CRC Press still promotes today, the extensive substitution of natural and seminatural ecological systems, or the self-maintained components of Natural Capital (NC), into human-dominated components. Consequently, most of the natural and seminatural components, particularly wetlands, have been seen until recently as “wastelands.” These areas are being extensively replaced by intensive crop farms, tree plantations, commercial fish culture, harbors, and industrial complexes or human settlements. 2–6 The lack of scientific background for understanding and estimating the multi- functional role of wetlands associated with the sectoral approach has resulted in lack of appreciation by policy and decision makers of the resources and services that these types of systems have produced. However, these are some of the most productive units in the ecosphere. They provide a wide range of self-maintained resources and services, from the viewpoint of energy and raw materials. They replace such self-regulated systems totally or, to a very great extent, they depend on the input of fossil auxiliary energy and inorganic matter (e.g., chemical fertilizers) as well as on human control mechani- zation (e.g., high-tech equipment for agriculture). Thus the ecological footprint (EF) of many local and national socio-economic systems (SESs) themselves become highly dependent on fossil fuels and underperform in providing services. The EF basically tries to assess how much biologically productive area is needed to supply resources and services, to absorb wastes, and to host the built-up infrastructure of any particular SES. 7 There has been an increase in scientific understanding and awareness among a growing number of policy and decision makers, especially in recent years. They now recognize that the structure and metabolism of any sustainable SES should be well rooted in a diverse, self-maintained, and productive EF. This has launched a new philosophy, derived from the theory of systems ecology and ecological economics, dealing with “sustainable market and sustainable socio-economic development.” This is an ecosystem approach, and new managerial patterns have emerged, consisting of ecosystem rehabilitation or reconstruction for the improvement of the EF and conservation through adaptive management of spatio-temporal relationships among SES and the components of NC. In recent years much work has been done to promote these new concepts. Objectives and patterns now focus on reconstruction and management of natural or seminatural ecological components (e.g., wetlands) as major initiatives in the EF of many SESs. However, principally we are still in the process of conceptual clarifi- cation, strategy, and policy development as well as designing and developing the operational infrastructure or smaller scale of projects implementation. This chapter presents a comprehensive analysis of the existing concepts, knowledge, and practical achievements in the integrated or ecosystem approach for sustainability or adaptive management of the relationships among SES and the components of NC. It is an attempt to improve the conceptual framework and provide an operational infrastructure for modeling and sustainable use and development of lagoons, one of the components of the coastal landscape most sensitive and vulnerable to human impact. This chapter thus provides the overall framework for developments discussed in the following chapters of the book. L1686_C02.fm Page 8 Monday, November 1, 2004 3:28 PM © 2005 by CRC Press 2.2 CONCEPTUAL FRAMEWORK OF SUSTAINABLE USE AND DEVELOPMENT Since the Brundtland Report (1987 WCED) considerable effort has been directed toward the development of a general definition of sustainability in order to implement the vision of sustainability in practical policy decisions. There has been worldwide recognition of the global “ecological crisis” faced by human civilization especially after the UNCED Conference/Rio 1992. This has prompted those responsible for formulating and implementing strategies and policies for economic development to balance the spatio-temporal structure and metabolism of SES with the spatio-temporal organization of the “environment” or with biophysical structures, the NC, and their production and carrying capacity. In this respect, this is an attempt to assess and integrate a wide range of operational definitions that have been developed and checked in recent years. 3–6,8–24 The following were identified as the basic requirements that must be met in order to put into practice the concept of sustainability. 1. Assessment of the conceptual and methodological development of sustainability that ensures establishment of state-of-the-art definition and identification of main gaps and shortcomings and, therefore, the need for further development and improvement. 2. Formulation of the basic elements of a dynamic model for co-development of SES and NC or for sustainable use and development to serve as the basis for promoting local, regional, and global transition. 3. Identification of the advantages and opportunities that each country and region may have as well as the limits or constraints with which they may be faced in the designing and implementing of long-term “co-development” strategies and action plans. 4. Identification of existing shortages and gaps in the policy and decision- making process dealing with sustainability and formulation of a comprehensive and dynamic model for the “decision support systems (DDSs).” This will serve as the interface, or the operational infrastructure, and thus enable us to balance the spatio-temporal relationships and the mass and energy exchanges between the NC structure, serving as the footprint, and the SES. What follows is a brief description of the basic conceptual and methodological elements to be relied upon in the co-development of SES ⇔ NC vision of sustainability as well as the structure of the dynamic DSS that can put sustainability into practice. The concepts and methods dealing with the “environment” have changed and improved as ecological theory usually described as “biological ecology” has developed from its early stage. The current ecological theory is more often and more appropriately defined as “systems ecology” (Figure 2.1). The identification and description of the natural, seminatural, human-dominated, and human-created environment has changed as well. This change was from a former conceptual model that defined the environment as an assemblage of factors—air, water, soil, biota, and human settlements—to the L1686_C02.fm Page 9 Monday, November 1, 2004 3:28 PM © 2005 by CRC Press FIGURE 2.1 Growth and evolution of the science of ecology. (After Vadineanu, A., Sustainable Development: Theory and Practice , Bucharest University Press, Bucharest, 1998. With permission.) The development of theory focused on the concept of the hierarchical organization of the natural, physical, chemical, and biological environment as well as on that which humankind dominated and created. System identification and dynamics of productivity and carrying capacity are the main objectives. Modeling and systems analysis are the basic tools. The development of theory was focused on a concept of ecosystems that recognized the strong relationships between biocoenoses and physical and chemical environments (biotops). The identification of real entities was focused mainly on biocoenoses. Sectoral and reductionist approach still prevail. The development of theory was focused on concepts dealing with individuals, cohorts, populations/ species, plant associations, animal associations, and biocoenoses. Intra- and inter-specific relationships as well as the relationships between “organisms and abiotic factors” have been the main tasks. The identification of real entities was neglected, and the sectoral approach has prevailed. AUTECOLOGY SINECOLOGY STRUCTURE ENERGETICS BIOGEOCHEMICAL CYCLES DIVERSITY/ STABILITY SYSTEMS ECOLOGY Evolution Growth Occurrence and development of premises Haeckel 1868 (year of the birth of the science of ecology) ECOSYSTEMS ECOLOGY BIOLOGICAL ECOLOGY 1700 1800 1850 1900 1930 1960 1990 L1686_C02.fm Page 10 Monday, November 1, 2004 3:28 PM © 2005 by CRC Press most recent thinking that considers the environment as a “hierarchical spatio-temporal organization.” 6,25–27 (Figure 2.2 and Figure 2.3). Ecological systems, as organized units and components of the hierarchy, are described as self-organizing and self-maintaining systems, or as “life-supporting systems.” They have been described as nonlinear dynamic and adaptive systems with evolving production and carrying capacity. These nonlinear systems go through successive phases of adaptive cycles: growth (R); accu- mulation or maturization (K); release or “creative destruction” ( Ω ); and restructuring and reorganization ( α ). 28,29 FIGURE 2.2 Relationships between taxonomic and organizational hierarchies of the living systems (A) and their integration within the hierarchy of life-supporting systems or ecological systems (B) A 1 = diversity of living organisms and hierarchical order of the taxa established based on the similarity between ordered entities. A 2 = hierarchical organization of living organisms in large and complex biological systems. B = hierarchy of spatio-temporal organization of the upper layer of lithosphere, hydrosphere, troposphere, and biosphere. (After Vadineanu, A., Sustainable Development: Theory and Practice , Bucharest University Press, Bucharest, 1998. With permission.) Ecosphere Land or Seascapes Elementary Ecosystems Biomes Hierarchy of life-supporting systems Superkingdom Hierarchy of biological systems Population/species A 2 A 1 A B Macroland or Seascapes Regional complex of biocoenoses Biosphere Biocoenoses Kingdom Subkingdom Phylum Subphylum Class Subclass Order Suborder Family Subfamily Genus L1686_C02.fm Page 11 Monday, November 1, 2004 3:28 PM © 2005 by CRC Press FIGURE 2.3 Hierarchical organization of the natural, human-transformed, and human-created physical, chemical, and biological environment. According to existing knowledge concerning the organization of life, we can distinguish five hierarchical levels above biological individuals and four spatio-temporal levels within the ecological hierarchy. It must be noted that three- dimensional space of the hierarchical organization integrates upper lithosphere, ocean basins, and troposphere, and the time constants of the ecological systems are in years, decades, centuries, or millennia. (After Vadineanu, A., Sustainable Development: Theory and Practice , Bucharest University Press, Bucharest, 1998. With permission.) 0 5 ×10 2 5×10 6 10 5 0 10 10 2 10 3 10 4 Hierarchy of Ecological Systems Time scale (years) Space scale (km 2 ) Macroregional network of HGMUs Macroregional assemblage of biocoenoses or BIOMs Regional complex of biocoenoses Regional network of HGMUs BIOCOENOSE HGMU or BIOTOP Population/ species II MACROREGIONAL COMPLEX OF ECOSYSTEMS or (Land and Seascapes) III MACROREGIONAL COMPLEX OF ECOSYSTEMS (Macroland or Seascapes) E L E M E N T A R Y E C O S Y S T E M IV ECOSPHERE BIOSPHERE TROPOSPHERE Hierarchy of Life Systems Hierarchy of Hydrogeomorphological Units (HGMU) I L1686_C02.fm Page 12 Monday, November 1, 2004 3:28 PM © 2005 by CRC Press The ecological hierarchy comprises two main hierarchical chains of ecological systems that show a marked and evolving dichotomy in spatio-temporal development: 1. Self-maintained natural and seminatural ecological systems that provide a wide range of natural resources and services 2. Human-dominated ecological systems that depend to varying degrees on commercial auxiliary energy and material inflow (e.g., agriculture, aquac- ulture) and human-made systems (e.g., urban ecosystems, industrial complexes), which are totally dependent on commercial energy and material inflow. 6,25,27 The divergent dynamics of these systems is the core of the so-called “ecological crisis.” Thus, the ecological hierarchy integrates both the components of the NC and those of the SES. Accordingly, the term biodiversity in its broad meaning covers, on the one hand, the components of NC together with their taxonomic and genetic diversity and, on the other hand, human social organization, and ethnic, linguistic, and cultural diversity. Biodiversity consists of NC and social and cultural capital. It provides both the EF that supports the SES with resources and services and the interface between NC and the structure and metabolism of the “economic subsystem” (Figure 2.4). It must be noted that, in order to make the transition from the current status of a strong dichotomy between SES ⇔ NC to that of co-development, there is a need to establish an internal balance between the economic subsystem and social and cultural capital. In the last decade a rapid shift has been observed from the sectoral, reductionistic, and inappropriate temporal (months and years) and spatial scale approach toward a holistic, adaptive, and long-term approach (decades and centuries). Systems analysis and modeling are used more extensively for the identification and description of the ecological systems (including SES) as large, complex, dissipative, and dynamic systems. However, the relationship between humans and nature more recently referred to as a “development and environmental” relationship or “economy and ecology” should be further reformulated. It should be recast as the mediated and dynamic relationship at local, regional, and global scales between the structure and metabolism of SES on one side, and the structure, productivity, and carrying capacity of the natural, seminatural, and human-dominated systems (NC) on the other (see Chapter 8 for details). The following conclusions are set forth: 1. Sustainability deals with co-development or balancing the dynamics of the spatio-temporal relationship between SES and NC. 2. The principles of free market economy, which negatively limit NC from contributing to SES, should be replaced by principles of “sustainable market economy.” This will require identification of the overall dynamic framework for co-development, according to the structure, productivity, L1686_C02.fm Page 13 Monday, November 1, 2004 3:28 PM © 2005 by CRC Press and carrying capacities of the local, regional, and global NC. In addition, ethical and moral criteria for sharing of resources and services within and among generations and among jurisdictions must be considered. 3. There is a need to establish thresholds for the constituent units of the NC and for the spatial relationship between NC and SES. Specifically, self- maintained and self-regulated ecological systems should represent more than 50% of the total NC of a country or region. So, the structure and metabolism of a particular SES should have a high degree of complemen- tarity with the structure, productivity, and carrying capacity of the domestic NC. 4. Although we refer to the NC as the EF for a particular SES, wetlands, and in particular lagoons, are a major component in the EF of any SES FIGURE 2.4 The general physical model of the socio-economic system and its relationships with Natural Capital (NC). A = the human-made physical capital: I = the infrastructure of the economic subsystem dependent on the renewable resources provided by the components of the NC; II = the industrial infrastructure of the economic subsystem dependent on “non-renewable” resources; III = systems for commercial energy production using fossil and nuclear fuels and hydro-power potential as primary resources; and IV = the human settlements infrastructure. 4.1, 4.2, and 4.3 identify the energy flow pathways; B = social capital; C = cultural capital; D = human-dominated components of the NC; E = natural and semi-natural components of the NC: 1 = flow of renewable resources; 2 = flow of raw materials; 3 = flow of fossil and nuclear fuels; 4 = flow of electrical energy; 5 = material and energy inputs (fertilization, agrotechnical works, irrigation, selection, etc.) to support the management of human-dominated systems; 6 = dispersion of heat and of secondary products (wastes) in the troposphere and in the HGMU components. (After Vadineanu, A., Sustainable Development: Theory and Practice, Bucharest University Press, Bucharest, 1998. With permission.) E A C B A D III II IV I 4.3 4.1 4.2 3 2 1 6 5 L1686_C02.fm Page 14 Monday, November 1, 2004 3:28 PM © 2005 by CRC Press (for example, they provide more than 24% of global net primary production and 60–65% of the world’s fish and shellfish production). 2 5. Finally, the need for a holistic or ecosystem approach to all our economic, social, and engineering activities is not merely a sustainable development strategic paper as often described by politicians, decision makers, and the public. It might be easier to use terms such as ecological crisis, integrated or interdis- ciplinary approach to the environment, or carrying capacity. However, it is very difficult to conceptualize the link between the ecological crisis and the dichotomy in the development of NC components and SES. The integrated or systemic approach also requires an understanding that the physical, chemical, and biological environment has a hierarchical organization that integrates the SES as human-dominated and human-created ecological systems dependent on mass and energy transfer with the other components of the hierarchy. It also must be understood that the carrying capacity of NC is linked to stability in a broad sense as well as to the dynamic capacity of the ecological systems to provide goods and services and to assimilate the wastes of SES. 5,6,11,16 2.3 SPATIO-TEMPORAL ORGANIZATION OF LAGOON ECOSYSTEMS The basic structural and functional units of the “environment,” widely known as ecosystems, and those from the next hierarchical level (Figure 2.3), known as land or sea/waterscapes, are the entities on which both scientific investigation and integrated or sustainable management are focused. Coastal lagoon ecosystems, and in particular the associated wetlands, are components of mixed land/sea/waterscapes that are complex dynamic systems. To approach and understand how these systems work and how they can be managed as NC, resources and service providers as well as spatio-temporal organization and structure must be identified. This structural model that represents the real world environment by depicting the dynamic components and their relationships in time and space is called a homomorph model . 30,31 Homomorph models are necessary for most scientists and managers to operate in the real world. Development and understanding of homomorph models are necessary for integrated management and for sustained use of NC that provide support for the SES. There have been, and still are, users of basic theoretical principles of the science of systems ecology who cannot associate these concepts with any real counterpart. Or, even if they do, such a structural model is either very superficial (with inappropriate space scales or oversimplification) or has no true agreement with the real system. One of the major targets in the field of applied systems ecology is the development of a specific methodology for ecosystem identification and landscape or sea/waterscape identification. 26,31–38 L1686_C02.fm Page 15 Monday, November 1, 2004 3:28 PM © 2005 by CRC Press Identification of the lagoons and the land/sea/waterscapes to which they belong is a step-by-step process that involves: 1. Development and implementation of extensive and intensive research and monitoring programs, at appropriate time and space scales, consisting of field observations, measurements, and sampling, combined with air pho- tography and remote sensing 2. Analysis of historical information and data 3. Identification of fauna and flora taxa and estimation of biomass, abun- dance, distribution, and dominance, as well as the trophic niche, relationship (food webs), production, and demographic structure 4. Assessment and description of the three-dimensional space distribution of major components of the hydrogeomorphic unit (HGMU) and variability of the lagoons (e.g., water volume, water movement, water retention time, stratification, and water-level oscillation, bottom nature, and chemistry) 5. Identification of lagoon ecotones, boundary conditions, and external driving forces In summary, all these steps are described in detail in various chapters of this book. This chapter identifies the crucial need for information systems dealing with the functioning and dynamics of lagoons in order to carry out sustainable use or adaptative management of lagoon resources and services. The remainder of this section provides a brief summary of information relative to lagoon function, dynamics, and management for sustained use and development. 2.3.1 L AGOON E COTONE The ecotones, or transition zones, are the border areas between the local ecosystems. They are elementary structural and functional units in various types of landscapes and sea/waterscapes. The physical, chemical, and biological components of ecotones have a linear development of tens of kilometers and usually a narrow transversal development of a few meters or, only very rarely, of hundreds of meters. In ecotones the joint HGMUs exhibit a marked discontinuity in at least one constituent (see Chapter 3). There is a very extensive literature dealing with the role of ecotone components of lagoons. 39–53 Useful conclusions that support managerial purposes are: • A spatio-temporal organization for biological components allows for the understanding of mass and energy exchanges between lagoon systems and surrounding ecosystems (e.g., agricultural, forests, urban, or marine shelf ecosystems). In fact, lagoon ecotones modulate and establish boundary conditions that are driving forces for the lagoon’s inner structural and functional dynamics. • As buffers, wetlands are more sensitive to the antropogenic forces as well as regional and global climate changes. Wetlands and, in fact, lagoon ecotones are habitats for many vulnerable species, a space for microevolution, or a space for longitudinal migration. • Due to their structural and functional features, lagoon ecotones should receive special consideration in any strategy and management program L1686_C02.fm Page 16 Monday, November 1, 2004 3:28 PM © 2005 by CRC Press [...]... and long-term effects); mathematical modeling K 1-3 3 Water [A3 ] k 1 -2 K 2- 4 2 Soil [A2] 4 Suspended particles [A4] K 3-5 5 Sediments [A5 ] K 4-5 LETHAL AND SUBLETHAL TOXICITY - Structural modifications: cell, tissues, organs - Effects on the biochemical and physiological processes - Mutagenesis and modification of the genetic structure of populations - Transfer among the trophodynamic modules - Biotranformations... Ecological Economics, 28 (2) , 24 5, 1999 25 Odum, E.P., Ecology: A Bridge between Science and Society, Sinauer Associates, Sunderland, MA, 1997 26 Pahl-Wostl, C., The Dynamic Nature of Ecosystems, John Wiley & Sons, New York, 1995 27 Vadineanu, A., Sustainable Development Theory and Practice Regarding the Transition of Socio-Economic Systems Towards Sustainability, UNESCO-CEPES, Bucharest, 20 01 28 Holling, C.S.,... November 1, 20 04 3 :28 PM © 20 05 by CRC Press Solar energy input (short wavelengths) L1686_C 02. fm Page 21 Monday, November 1, 20 04 3 :28 PM 2. 3.4 GENERAL HOMOMORPH MODEL FOR LAGOONS When the identification process of a given lagoon system is completed, the result should be a structural and functional model that preserves the basic structural and functional attributes of the lagoon and its spatio-temporal... action plans for integrated and © 20 05 by CRC Press L1686_C 02. fm Page 23 Monday, November 1, 20 04 3 :28 PM sustainable management of complex land/seascapes, where lagoons are major components • On average, only 0 .25 % of the solar energy reaching the land and ocean surface and 0.5% of the solar energy absorbed by the primary producers are concentrated in biomass26,54,58 (Figure 2. 7a) • The greatest part of... concentration (quality) in food chains (Compiled after Botnariuc, N and Vadineanu, A., 19 82; Odum, E., 1993; and Pahl-Wostl, C., 1995.) L1686_C 02. fm Page 24 Monday, November 1, 20 04 3 :28 PM © 20 05 by CRC Press C1 Ea L1686_C 02. fm Page 25 Monday, November 1, 20 04 3 :28 PM have the possibility of recycling the raw material necessary to photosynthesis and chemosynthesis and maximizing the efficiency of using... bacterioplankton; M2 = benthic microorganisms; C1 = herbivores; C1′′ = microfiltrators (e.g., rotifers, small cladocera); D = detritus-feeding populations; C2 and C2′′ = zooplanktonic carnivores; C2′ = carnivore invertebrate species; C3′ = benthos-feeding fish species; C3′ = plankton-feeding fish species; C4 = predator fish species; S and S′ = available stock of chemical elements or compounds L1686_C 02. fm Page 20 Monday,... human-dominated and human-created ones They should preserve the structural and functional characteristics and time constants of the real systems Formulation - cause-effect hypothesis Identification - set of parameters, state variables, and driving forces Formulating or Adapting - packages of mathematical models Long-term research projects for each category or ecological system Knowledge Base FIGURE 2. 12. .. ecotones; C = lagoon; F = Forest © 20 05 by CRC Press L1686_C 02. fm Page 22 Monday, November 1, 20 04 3 :28 PM nonliving organic matter or fossil energy), and makes the lagoon function as a productive, self-regulating, and self-maintaining system This involves a permanent inner transfer of mass, energy, and information that consists of three overall processes: 1 Energy flow 2 Biogeochemical cycling of chemical... the biogeochemical cycles occurring at the ecosystem levels (local cycles) and at the micro- and macro-landscapes and seascapes are closely interconnected, and in fact integrated in the global biogeochemical cycles (See Chapter 4 for details.) © 20 05 by CRC Press L1686_C 02. fm Page 28 Monday, November 1, 20 04 3 :28 PM • It is well defined that a chemical element is preferentially stored in one of the pools... fossil fuel (up to 1000 20 00 kcal⋅m 2 ⋅yr −1) • The quantity of energy absorbed and concentrated by the dominant populations or cohorts in the tropho-dynamic modules, represented by the first-order (herbivorous) and by the second- and third-order consumers, decreases from one tropho-dynamic module to another In general, the energy assimilated (absorbed and concentrated) by a tropho-dynamic module made . CONTENTS 2. 1 Introduction 2. 2 Conceptual Framework of Sustainable Use and Development 2. 3 Spatio-Temporal Organization of Lagoon Ecosystems 2. 3.1 Lagoon Ecotone 2. 3 .2 HGMU Spatio-Temporal Organization 2. 3.3. of concentrated energy and macro- and micro-elements L1686_C 02. fm Page 20 Monday, November 1, 20 04 3 :28 PM © 20 05 by CRC Press 2. 3.4 GENERAL HOMOMORPH MODEL FOR LAGOONS When the identification. exchange Turbulence Seepage Exchange with the sea Coastal erosion Evaporation Evapotranspiration Infiltration Surface run-off C F A E 2 E 2 E 1 L1686_C 02. fm Page 21 Monday, November 1, 20 04 3 :28 PM © 20 05 by CRC Press nonliving