Mte Research And The Global Forum

Critics sometimes argue that funding of, and attention to, MTE research is disproportionate because they occupy only about 2 of the Earth's land surface according to Koppen Cs climate zones (M ller 1982), or less than 1 using the more narrowly circumscribed definition of Aschmann (1973). This supposes that importance is a linear function of area, which implies that the collective GNP of all MTEs is approximately 4 that of the USA (Europa World Yearbook 1994). MTEs, however, have some...

Humaninduced Changes And Their Effects On Biodiversity And Ecosystem Function

Climate warming The anticipated warming from atmospheric loadings of radiatively active gasses is probably the greatest threat to the boreal region worldwide. Although the global circulation models disagree on the details of the extent of warming and drying, all agree that the greatest warming will take place in high-latitude regions, and most agree that mid-continent areas will become drier while maritime areas will become wetter (Schlesinger and Mitchell 1985). Climate warming will affect the...

The Scope Program

The SCOPE program consisted of a series of activities between 1991 and 1994, culminating in an overall synthesis meeting at Asilomar, California, in 1994. The program was launched in October 1991 with a meeting on background issues held in Bayreuth, Germany. This meeting brought together ecologists and population biologists, both directed toward evaluating the consequences of human-driven disruption of natural systems. In particular, there was an examination of the degree of redundancy within...

Maintaining Biodiversity Of Freshwaters

From an ecosystem perspective, the reason to preserve biodiversity is to preserve options for the future. The environment is certain to change because of natural fluctuations in the physical forcing of the biosphere and large-scale anthropogenic effects. We cannot predict which building blocks will be essentia for maintaining ecosystem or landscape processes in future environments. It is prudent to preserve taxa that may be crucial for ecosystem processes under new conditions. At a large scale,...

Learning and adapting to surprise

The ecological changes likely to occur in Chilean lakes and the management actions to be recommended are consistent with experience in North Temperate lakes. This convergence may indicate global patterns of ecosystem change which suggest that general guidelines for management can be derived, and that we do not need to study each system as if it was unique. It seems likely that nutrient enrichment and salmonid introductions will cause Chilean lakes to resemble many mesotrophic lakes around the...

Nekton Biodiversity And Mangrove Food Webs

Nekton (free-swimming organisms) food webs represent faunal guilds that utilize mangrove habitats for food and protection at different stages of their life cycle. Most of these organisms are migratory (while there may be some residents), and the ephemeral nature of the periods when these organisms utilize mangrove habitats contributes to the poor understanding of their ecology. Robertson and Blaber (1992) reviewed the results of four mangrove fish community studies in northern Australia where...

Stability And Species Richness

Discussions of the degree and causes of stability are frequently hampered by vagueness and inconsistency about what is meant by stability (Orians 1975). Stability may simply mean constancy, that is a low level of variation in some measurable property of the system. Stability may also refer to the resistance of the system to alteration by external perturbations (inertia), its speed of return to initial conditions following a perturbation (elasticity or resilience), the domain over which it...

Freshwater Ecosystems Linkages of Complexity and Processes

PERSSON, M. POWER AND D. SOTO 12.1 INTRODUCTION 12.1.1 Uses of Freshwaters Freshwater ecosystems are indispensable for life. Unlike some resources, there is no substitute for water. Its availability influences the distribution of Earth's major biomcs and the productivity of agriculture. Historically, fresh-waters have been a magnet for human settlement. Important human uses of freshwaters include drinking, fishing, industry, irrigation, recreation and transportation...

Conclusion biodiversity and ecosystem function from genes to regions

To conclude, we have identified how biodiversity, from genes to regions, may alfect ecosystem function in coral reefs. At a single reef, diversity in the life-history characteristics of reef biota, both within and among species, provides the basis for occupancy and survival in the broad range of environments that the reef provides. The diversity of a reefs zones is essential to the maintenance and accretion of the overall structure itself, and of its protein resources. Each zone's...

Mangrove Faunal Guilds And Ecosystem Function

Animal species co-occurring in mangrove forests can be separated into guilds characterized by the utilization of available resources (Ray and McCormick 1992). Fauna) guilds described in this section are basically resident species that exploit the habitat with different intensity in space and time, in contrast to the nekton guilds discussed below (Section 13.6). The utilization and exploitation of the mangrove habitat by faunal guilds, both resident and migratory, can contribute to the structure...

Info

Mean level of channel water al low tide Figure 13.6 Vertical zonation and abundance of epibenthos on Rhizophora apiculata trees, Phuket Island (Taken from Alongi and Sasekumar 1992 as modified from Frith et al. 1976). Species codes 1, Sea anemone sp.A 2, Sea anemone sp.B 3, Nemertine sp.A 4, Lepidonotus kumari 5, Betroiisthes sp. 6, Cibanarius padavensix 7, Diogenes avarus 8. Leipocten sordidulum 9, Tylodiplax tetra-tylophora 10, Batanas amphitrite 11, Chthamalus withersii 12, Ligia sp. 13,...

Facilitators as links between humans biodiversity and ecosystem function

Three case studies illustrate reef turn-off caused by population fluctuations in echinoderm facilitator species. In the first, the turn-off appears to be rapidly reversible without human intervention in human time scales in the latter two, the situation appears to be irreversible, or at least much slower than expected. Crown-of-thorns starfish. In the 1960s and 1980s, populations of the crown-of-thorns starfish Acanthaster planci, for reasons unknown, increased by several orders of magnitude...

Water quality and land runoff effects on biodiversity and ecosystem function

The water flowing onto a coral reef acts as a transport medium for materials (organic matter, nutrients, sediments, propagules - sec Section 15.3) which are beneficial when delivered at appropriate concentrations and frequencies, but may be deleterious when delivered in excess. Mechanisms for nutrient impacts on coral reefs Four mechanisms for nutrient impact on reefs are rccognised, although cause and effect have been difficult to establish unequivocally (Bell 1992). Should they reach a reef...

Effect Of Species Diversity On Ecosystem Function

We now explore how changes in species diversity affect ecosystem function in order to test our null hypothesis. For this purpose we make use of natural and unplanned human experiments involving the addition and or removal of plant and animal species from natural savanna ecosystems. 8.4.1 Invasion of South American and Australian savannas by African Several species of African grasses (such as Hypharrenia rufa, Melinis minuli-flora and Panicum maximum) have becomc naturalized in the South...

Savanna Structure And Function

Litterfall And Decomposition Plant

Ecosystem function can be interpreted in two ways. It can refer to the flow of energy and nutrients through an ecosystem or to the flow of species populations through time, i.e. the persistence of species populations and their properties, what Holling calls the resilience of the system (Holling 1973, 1986 Solbrig 1993). The usual way of looking at ecosystem function is to consider only the flow of energy and nutrients. We first discuss how species characteristics control the flow of energy and...

References

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