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The Stockholm archipelago is a brackish-water archipelago that extends along the Swedish east coast, just south of the border between the Bothnian Sea and the northern Baltic Proper. The Stockholm archipelago stretches about 200 km from Singö in the north to Nynäshamn in the south (Fig. 14.1). A nearly continuous belt of islands stretches eastwards from the Stockholm archipelago across to the Åland islands and the Åbo archipelago in Finland. [ABSTRACT FROM AUTHOR]

In this chapter, we describe the unique physical and biogeochemical conditions of the Gulf of Finland. Although morphologically a direct continuation of the Baltic Proper, several features distinguish the Gulf markedly from other parts of the Baltic Sea. Relative to its surface area, the Gulf of Finland has the largest catchment area and highest freshwater inflow within the Baltic Sea. The external loading of nitrogen (N) and phosphorus (P) relative to the surface area of the Gulf are about two and three times, respectively, those of the Baltic Sea. The Gulf of Finland has a distinct but unstable salinity stratification, which makes the sea area very sensitive to external perturbations. At times, this may lead to e.g. deep water anoxia/hypoxia, elevated benthic release of P and extensive cyanobacterial blooms. The poor oxygen conditions in the Gulf are caused primarily by the voluminous spring bloom and preceding sedimentation of detrital plankton material, which in turn is caused by high wintertime nutrient concentrations. Poor oxygen conditions and intensified sediment release of P have led to strongly increasing deep-water and winter concentrations of inorganic P over the last 10 years. In contrast, N concentrations have decreased since the late 1980s, suggesting the effect of decreased external N loading at the same time. This latter phenomenon probably contributed to the decreased magnitude of the phytoplankton spring blooms in the 1990s. [ABSTRACT FROM AUTHOR]

Odense Fjord (Table 16.1) is a shallow Danish fjord affected by freshwater and nutrient discharges from a large catchment area (1,060 km2) dominated by agriculture. In contrast, the nearby Kerteminde Fjord/Kertinge Nor (Table 16.1) is a shallow fjord system with a small catchment area (36 km2) and consequently small freshwater discharges, and where the water exchange and nutrient dynamics are greatly affected by density-driven currents caused by frequently changing salinities in the Great Belt. In both fjord systems, filter-feeding macro-invertebrates play a significant role in the biological structure as will become apparent from the two case studies detailed in this chapter. [ABSTRACT FROM AUTHOR]

Neva Estuary is located in the eastern part of the Gulf of Finland. The western boundary of this estuary is not clearly defined geographically, due to the lack of a comprehensive definition of an estuary in general (Elliott and McLusky 2002). In the past, several attempts at subdividing Neva Estuary have been undertaken by researchers. One of the most recent classifications (Golubkov et al. 2003a) distinguishes certain parts of Neva Estuary that are well separated by natural and/or artificial boundaries. Some publications, however, present schemes of this estuarine water system in which Neva Bay is falsely excluded from the estuary subdivision, whereas in fact it should be considered as the head of Neva Estuary. [ABSTRACT FROM AUTHOR]

Due to their geology, Baltic coastal areas are highly diverse. Thus the northern and northeastern Baltic is shaped by rock basement of the Scandinavian plate, whereas moraine landscapes and soft soils are typically found throughout the southern, southwestern and southeastern Baltic. Furthermore, constantly changing conditions occur due to the rising northeastern edge and trailing southern shore, in addition to the successive formation of mature shorelines throughout the south and southeast. This results in at least ten different coastal forms (see Chap. 2 by Schiewer, this volume; Fig. 2.1), which can comprise a variety of soil formations ranging from silt, sand and gravel to various types of hard soil. [ABSTRACT FROM AUTHOR]

The Odra (German: Oder) estuary, located in the southern Baltic Sea, consists of the Szczecin (Oder-) Lagoon and the Pomeranian Bay (Fig. 5.1). The Szczecin Lagoon (687 km2) is shared by Poland and Germany and is naturally subdivided into the "Large Lagoon" (Polish: Wielki Zalew) on the Polish territory and the "Small Lagoon" (German: Kleines Haff) on the German side. The Lagoon connects with the Pomeranian Bay via three outlets. With an average depth of 3.8 m, the Szczecin Lagoon is a shallow water body: its maximum natural depth is 8.5 m, but dredging in the shipping channel produces depths exceeding 10.5 m. The channel intersects the Lagoon to link the River Odra mouth and the harbour of Szczecin with the Baltic Sea. Data of the Maritime Office of Szczecin show ca 1.5 million m3 sediment per year to have been dredged during the last 50 years to maintain the average channel depth of 10.5 m (Minning 2004). [ABSTRACT FROM AUTHOR]

This chapter is focused on the different types of benthic, plant and animal communities found in the photic zone of the Askö area. The description of these phytobenthic communities is also relevant for the entire Swedish coastline of the Baltic Proper. Only a few species disappear from the southern coast up to the Askö area and a few new species of freshwater origin occur at the northern border of the Stockholm Archipelago. For the Askö area, a comparison is made with the 1970s, and trends over the last 10 years are described. Some original data are presented. The deeper benthic and pelagic systems are more briefly described. Only a fraction of the results of the extensive research carried out in the Askö area since the 1960s can be presented in this review. [ABSTRACT FROM AUTHOR]

The Darß-Zingst Boddens (DZB) represents the typical bodden coasts of northern Germany, which stretch from the Fischland-Darß-Zingst peninsula via the islands of Hiddensee, Rügen and Usedom to the Polish island of Wolin. The "double coasts" show the typical features of level coasts at the seashore while, at the back, the indented boddens and lagoons are inner seawaters that are subject to a progressive phytogenic silting-up. [ABSTRACT FROM AUTHOR]

Coastal waters surround, on the one hand, seas and oceans, while on the other they form transitional zones between inner coastal waters and offshore regions. With respect to hydrology, basic differences exist between the coastal waters of the North Sea and those of the Baltic Sea. Geographically, the two sets of coastal waters can be defined thus: [ABSTRACT FROM AUTHOR]

Haapsalu and Matsalu Bays (Fig. 11.1) are situated in the Väinameri area (the "Sea of Straits") — a low-water region between continental Estonia and its western islands. The surface areas of Haapsalu and Matsalu Bays are small: 50 and 67 km2, respectively. These values are gradually decreasing owing to landlift and riverine sediment discharge. The base rock is formed by the limestone, marl and dolomites of the Ordovician and Silurian deposits. The bed sediments are sands, gravels and clays of various structures. The bays are relatively shallow, with a maximum depth of less than 5 m and an average depth of 1.5-2 m (Lutt and Kask 1980). [ABSTRACT FROM AUTHOR]

Because of their special geological and hydrographical properties, near-shore zones are thought of as highly productive ecosystems serving as a potential source for the organic carbon deposition of the deeper Baltic Sea areas (Bodungen and Zeitschel 1996; Emeis et al. 1999; Witt et al. 1999). However, since the hydrodynamic, chemical and biological features of near-shore coastal zones are highly diverse, this general statement was tested by carrying out small-scale investigations at two distinct sites taking into consideration the specific properties of the investigated areas. The two distinct areas of the German coast in the southern Baltic Sea selected were "Tromper Wiek" (TW), at the northwest part of the island of Rügen, and "Koserow" (KW), at the middle part of the island of Usedom. The test sites are located at the south-western end of the Baltic Proper, near to the Darß sill. TW is located near to the Arkona Basin. [ABSTRACT FROM AUTHOR]

The Gulf of Riga (Fig. 10.1) is a relatively shallow and isolated water-body with a surface area of 16,330 km2. On its eastern and southern sides it is flanked by the Estonian and Latvian mainlands, and on the northern side by the islands of Saaremaa and Muhu. The Gulf of Riga is connected to the Baltic Proper via the Irbe Strait, and to the Väinameri Archipelago Sea by the Suur Strait. Annual river inflow (Table 10.1) ranges between 18 and 56 km3 (on average 32 km3), while the volume of the gulf is 424 km3. The residence time of water masses is 2-4 years (HELCOM 1996). The Gulf of Riga receives fresh water from a huge drainage area (134,000 km2), mostly entering the southern part of the basin (Andrushaitis et al. 1995). In general, the bottom relief of the area is quite flat, with gentle slopes towards deeps. The northern part of the Gulf is characterised by a wide coastal zone with diverse bottom topography and extensive reaches of boulders. The southern part of the Gulf of Riga is more exposed; steep and soft substrate prevails. In the deeper parts of the Gulf, silty sediments prevail. [ABSTRACT FROM AUTHOR]

Curonian lagoon (Fig. 9.1) is a large (1,584 km2) (Žaromskis 1996) coastal water body connected to the south-eastern Baltic Sea by a narrow (0.4-1.1 km) strait (Klaipėda port area). The mean depth of the lagoon is approximately 3.8 m (Žaromskis 1996). The strait is ca. 11 km long, with artificially deepened waterways down to 14 m depth. The eastern side of the lagoon (mainland shore) represents a shallow plain, gently sloping westward down to a depth of 1-2 m, whereas the western side (the Curonian Spit shore) reaches up to 4 m depth (Table 9.1). [ABSTRACT FROM AUTHOR]

The Vistula Lagoon is located at the southern coast of the Baltic Sea (Fig. 8.1). It stretches along the shore for ca. 91 km. The width of the lagoon varies between 2 and 11 km, and the water volume and surface area are 2.3 km3 and 838 km2, respectively. The average lagoon depth is 2.7 m; the maximum depth excluding the artificially dredged navigable channel is 5.2 m. The state border between the Kaliningrad region (Russia) and Poland divides the lagoon into two parts, which account for 64% and 36% of the water volume and 56.2% and 43.8% of the lagoon area, respectively. The length of the lagoon coastal line is estimated as 270 km (Poland 111 km, Russia 159 km). The single Nasypnoi Island is in the deepest part of the lagoon (Lazarenko and Majewski 1971). [ABSTRACT FROM AUTHOR]

Located on the shores of the Gulf of Gdańsk, the Tri-Cities agglomeration, which, in addition to other small towns, has a population of 760,000, is comprised of the port cities Gdańsk and Gdynia and the spa town of Sopot. The gulf is subjected to different rates of anthropogenic pressure and is extraordinarily interesting from a scientific point of view. Poland has recommended that two regions in this basin be declared Baltic Sea Protected Areas HELCOM BSPA: the Nadmorski Landscape Park and the Mierzeja Wiślana Landscape Park (Kruk-Dowgiałło et al. 2000a, 2000b). The western region of this basin was included in the NATURA 2000 network in 2004 (Fig. 7.1). [ABSTRACT FROM AUTHOR]

The Baltic Sea (Fig. 1.1) stretches from the Gulf of Finland to the Kattegat over 1,200 km in the east—west direction and from Odra Bay to Bothnian Bay near the polar circle over 1,300 km in the north—south direction. It covers an area of 415,266 km2 and has a water volume of approximately 21,000 km3. Traditionally, it has been divided into five main regions (Table 1.1). [ABSTRACT FROM AUTHOR]

The Greifswalder Bodden, Wismar-Bucht and Salzhaff have an open connection to the Baltic Sea in common. Loads originating from the shore-side can thus be transported to the adjacent Baltic basins more quickly. The shorter residence times reduce the possibility of self-purification of these waters. Loads and disturbances in these ecosystems have an immediate effect on the Baltic Sea. [ABSTRACT FROM AUTHOR]

As a result of high deforestation and non-sustainable land use there exists a substantial and increasing amount of unproductive land in Ecuador, especially concerning over-used, degraded or abandoned pastures (see Chapter 4 in this volume). The loss of productive land is particularly disastrous because forestal and agricultural land use is one of the main generators of income in rural areas. It is interesting to see that 90% of the area annually afforested in Ecuador (3500ha) are realized in the Andean region, where the socio-economic and ecological functions of the forests are of prominent importance (FAO 2006). However, despite the exorbitant number of 2736 native tree species in Ecuador (Jørgensen and León-Yánez 1999), forestation activities are almost exclusively based on exotic species, mainly pines and eucalypts. [ABSTRACT FROM AUTHOR]

So far, little is known about the impact of habitat disturbance and subsequent regeneration on mega-diverse insect assemblages native to Andean mountain rainforests. The speciose insect order Lepidoptera provides an ideal target for such analysis. Butterflies and moths are probably the taxonomically best known insects. Moreover, lepidopterans are functionally connected in two-fold manner with the vegetation they inhabit: through the host-plant affiliations of their phytophagous larvae, as well as through the widespread need for plant-derived resources (e.g. floral nectar, rotting fruits, secondary plant compounds) during the adult phase of the life cycle. However, apart from a few recent studies on moths (for a summary, see Fiedler et al. 2007a, b), most available analyses referred only to the butterfly fauna (or some butterfly guilds such as frugivores; e.g. DeVries et al. 1997; DeVries and Walla 2001), even though moths comprise a far larger fraction of lepidopteran diversity than butterflies. Therefore, we chose two large moth families (Arctiidae, Geometridae) as models to study species diversity and turnover in a successional gradient at the edge of a natural montane rainforest in the Ecuadorian Andes. Species of both families tend to differ in their life histories, habitat fidelity, and resource requirements (e.g. Holloway 1984; Kitching and Rawlins 1999; Minet and Scoble 1999; Holloway et al. 2001). Thus we expected that arctiid and geometrid moth ensembles should respond with differential sensitivity to environmental change in the course of successional processes. E. Beck et al. (eds.), Gradients in a Tropical Mountain Ecosystem of Ecuador. Ecological Studies 198. [ABSTRACT FROM AUTHOR]

The climate of the research area is mainly influenced by the easterlies of the trade wind regime (see Chapter 8 in this volume) and thus by the Atlantic circulation patterns. The Pacific circulation patterns play a minor role but associated westerlies modify the regional weather in the study area, especially in the austral summer. Due to the dominance of the Atlantic circulation, the Pacific ENSO phenomenon does not cause extraordinary anomalies, whereas La Niña situations induce somewhat stronger effects (see Chapter 20). Weather extremes in the study area are initiated by aperiodic but regularly occurring circulation patterns. Cold air surges (friajes) from the south can cause severe plunges in air temperature, which in turn can affect plant life. One unexpected finding is the marked impact of nocturnal mesoscale circulation processes in the near Amazon on cloudiness and rainfall in the Rio San Francisco valley. Also remarkable is the strong spatial gradient of humidity between Loja and the RBSF, over a beeline distance of less than 20 km where the crest of the eastern Cordillera is a clear weather divide. While rainfall at RBSF peaks in austral winter, the basins west of the main Cordillera are characterized by two rainy seasons peaking in March and October, respectively. The rainfields that generate the perhumid climate of the RBSF cannot reach the basin of Loja because they are released from relatively shallow orographic cap clouds in the upper part of the RBSF area, which are not able to pass the main ridge of the eastern Cordillera. The summer rains in the austral summer, especially in the basins of Loja and Vilcabamba, are related to a westerly stream flow initiated by the Pacific circulation. [ABSTRACT FROM AUTHOR]

Tropical forests are characterized by a high diversity of tree species together with a low abundance of individual species. This has far-reaching implications on strategies for a sustainable management and conservation of their genetic resources. [ABSTRACT FROM AUTHOR]

In this chapter, we focus on the influence of natural and anthropogenic disturbance — and recovery cycles — on soil physical properties. [ABSTRACT FROM AUTHOR]

In the RBSF, as in many tropical mountain regions, the topography consists of a complex system of crests, ridges, steep slopes, valleys and gorges. These different physical features have an influence on the vegetation composition, stand structure and further processes, which also change with increasing elevation (Lieberman et al. 1996; see Part III 1 in this volume) as well as at the same elevation in line with the topography along a horizontal gradient (Takyu et al. 2002; Tanner 1977). ‘The topography, including the elevation, is a major physical factor, which affects the composition, growth, and distribution of tropical forests' (cf. Basnet 1992). Climate parameters such as wind speed and light condition or transpiration (see Chapter 16 in this volume) may be different at ridges and gorges. Because of erosion of soils, soil contents are expected to accumulate on lower slopes and in valleys and gorges (Kubota et al. 2004). Therefore, the hypothesis for the study was that changes in abiotic parameters alter the vegetation structure and composition along the vertical gradient as well as along the horizontal gradient formed by the topographical structure in the lower part of the RBSF (see Chapter 10.3 in this volume). [ABSTRACT FROM AUTHOR]

Successional stages of a vegetation development leading from bare soil to a plant cover dominated by bushes and a few pioneer trees have been described by Beck et al. (see Chapter 27 in this volume). Under optimal conditions this succession continues to a secondary mountain forest. Analyzing this is an enormous challenge, not only from a scientific but also from a logistic viewpoint. Tropical secondary mountain rain forests appear to be the most difficult vegetation type for a systematic investigation. [ABSTRACT FROM AUTHOR]

The complexity of flow patterns and occurrence of preferential flow in soils depend upon spatial heterogeneity of the upper boundary condition, heterogeneous distribution of soil hydraulic parameters and soil structure (Flury et al. 1994; Kulli et al. 2003). In a tropical rainforest, the canopy transforms the spatially almost uniform rainfall to heterogeneous patterns of throughfall on soil surface. These patterns continue in the soil amplified by its own heterogeneity. More details on canopy interactions and water relations are given by Wilcke et al. (Chapter 12 in this volume). [ABSTRACT FROM AUTHOR]

In tropical montane forests, aboveground net primary productivity (ANPP) usually decreases with increasing altitude. Besides low photosynthesis (Kitayama and Aiba 2002) and direct impact of low temperatures on plant growth (Hoch and Körner 2003), low ANPP at high altitudes has often been attributed to nutrient limitation (Bruijnzeel et al. 1993; Bruijnzeel and Veneklaas 1998; Tanner et al. 1998). [ABSTRACT FROM AUTHOR]

There are only a few studies on soils and their bioelement status in primary forest and forest-derived land use for mountain rainforests (Rhoades et al. 2000); most investigations up to now have focused on lowland tropics. Important changes in physical and chemical soil characteristics and biological cycles follow pasture establishment and can affect soil fertility and the interaction of soils with atmosphere and downstream aquatic ecosystems (Reiners et al. 1994; Feigl et al. 1995; Koutika et al. 1997; Deborah et al. 2001; Cerri et al. 2003). Some of these changes, such as increase in pH and exchangeable bases that follow forest cutting and burning for pasture establishment, are practically universal and occur in a wide variety of sites and different soils. Changes to other biogeochemical attributes, such as soil organic matter turnover, are more variable increasing under pasture in some locations and decreasing in others (Neill et al. 1998; Rhoades et al. 2000; Powers and Veldkamp 2005). [ABSTRACT FROM AUTHOR]

The construction of roads and power supply lines causes disturbances which differ from forest clearing for farming purposes by several major issues: The disturbance is linear and narrow but extends over a wide distance.Not only is the topsoil affected but usually the entire soil layer is stripped and, especially in a mountainous area, even the slopes are clipped and ablated and broadenings are banked.The forest is usually cleared mechanically and not by the use of fire.Once the traffic route is completed, disturbance continues either by regular cutting of the vegetation along the wayside or by landslides of various dimensions caused by erosion of the steep embankments. [ABSTRACT FROM AUTHOR]

Burning is still the common method used by settlers (Colonos; see Chapter 3 in this volume) to clear the primary forest for new farming areas. Every fire, irrespective of being lit inside or at the edge of the forest, kills the trees by burning or by the emerging heat. A fringe of dead, but not charred, trees is always found where forest has been cleared by fire. Later, when these heat-killed trees have completely dried up, they can be used to start a new fire. [ABSTRACT FROM AUTHOR]

Lösch (2001) concluded that information on the ecophysiology of tropical mountain trees — key components for the understanding of the functional role of vegetation in these ecosystems — is entirely missing; therefore we concentrate on transpiration. Available knowledge on stands is almost exclusively from catchment studies (e.g. Bruijnzeel and Proctor 1995; see Chapter 12 in this volume), but types of "gully", "slope" and "stunted" forests are found everywhere. To evaluate their contribution to water consumption and buffering in the landscape it is essential to characterize these forest types individually, here via up-scaling from sap flow measurements on individual trees to plot-scale. In this context it is important to know whether sap flow varies species-specifically (then many species have to be studied) or whether the size of individual plants, their life-forms, and associations with functional groups are more important (then only a few representative individuals need to be investigated). [ABSTRACT FROM AUTHOR]

In tropical forests, the first step in the destruction cycle is usually the over-exploitation of high value timber, leading not only to extinction of the extracted species (Silva Matos and Bovi 2002) but also to the conversion of the forests into pastures in many cases (Wunder 1996b). In many highlands of Ecuador the productivity of the pastures is depleted due to the invasion of bracken fern (see Chapter 28 in this volume), which finally leads again to the conversion of primary forests by local farmers (Paulsch et al. 2001; Hartig and Beck 2003). This process usually is accompanied by loss of biodiversity (Brooks et al. 2001), increased erosion, changes of hydrology (Bruijnzel 2004), and further environmental disturbances. More information on deforestation in Ecuador is given by Mosandl et al. (Chapter 4 in this volume). [ABSTRACT FROM AUTHOR]

By now it is sufficiently well understood that any attempt to preserve primary forest in the tropics is destined to fail if the interests and use claims of the local population are not at the same time, and in the long term, taken into account. Therefore, in addition to strict protection of the forests, an integrated concept of nature conservation and sustainable land use development needs to be sought (e.g. Ellenberg 1993). The DFG research project presented here will figure out the extent to which traditional ecological knowledge and indigenous biodiversity management strategies can be made available for a long-term land use development. The project chose to use a specialized approach, namely the investigation of indigenous/local knowledge systems as part of the ethnoecological methodology (e.g. Münzel 1987; Posey and Balée 1989; Warren et al. 1995; Müller-Böker 1999; Nazarea 1999). In biodiversity-rich places local people usually have a detailed ecological knowledge e.g. of species, ecosystems, ecological relationships and historical or recent changes of them. Numerous case studies have shown how traditional ecological knowledge and traditional practices serve to effectively manage and conserve natural and man-made ecosystems and the biodiversity contained within (e.g. Posey 1985; Toledo et al. 1994; Berkes 1999; Fujisaka et al. 2000; Pohle 2004). In ongoing interdisciplinary and integrative research projects like BIOTA AFRICA (Biodiversity Monitoring Transect Analysis in Africa, German Federal Ministry of Education and Research), STORMA INDONESIA (Stability of Rainforest Margins in Indonesia, German Research Foundation, Collaborative Research Centre 552) or within the interdisciplinary programme of the National Centre of Competence in Research North-South implemented by the Swiss National Science Foundation (SNSF), investigations on traditional ecological knowledge and biodiversity management are an integral part. [ABSTRACT FROM AUTHOR]

Landslides are part of rapid mass movement events, and considered processes of denudation. The classification scheme in Fig. 24.1 identifies different processes with regard to the type of movement in relation to the type of material (Varnes 1978). Other classification systems (e.g. Ahnert 1996; Crozier 1986a; Dikau et al. 1996; Hutchinson 1988) consider the medium of transport (gravitation, pore water, snow, soil ice, etc.) or the velocity of the phenomenon (rapid, intermediate, slow). [ABSTRACT FROM AUTHOR]

Canopy gaps are integral parts of every primary mature forest ecosystem, no matter whether it is a temperate or tropical forest. They can be caused by various factors, including landslides, strong winds and injury or death of individual trees. Landslides and uprooting may open-up the soil to the mineral horizon; other causes may not affect soil structure such drastically. Many fast growing, shade-intolerant, pioneer species are adapted to canopy disturbance and they need light gaps to establish and to reach maturity. Late-successional canopy tree species often tolerate shade as juveniles, but most of them also require disturbance of the forest canopy to reach reproductive maturity (Hartshorn 1980; Whitmore 1989). [ABSTRACT FROM AUTHOR]

The tropical montane cloud forests of southern Ecuador have developed on poor soils characterized by low nutrient availability and high acidity (Beck and Müller-Hohenstein 2001; Brummitt and Lughadha 2003; Chapter 13 in this volume). Their nutrient balance might be affected by atmospheric inputs via precipitation, as indicated by our results. Especially the high input of fog and wind-driven rain can cause a significant deposition of ionic loads, because this precipitation type has a longer impact time on vegetation surfaces than falling raindrops. [ABSTRACT FROM AUTHOR]

Tropical mountain rainforests are commonly regarded as a stable ecosystem in which life processes face almost invariable environmental conditions. However, as discussed for the eastern Cordillera of Ecuador in Chapter 8, even the perhumid tropics experience a more or less pronounced seasonality of precipitation patterns. Intra annual fluctuations of temperature are small and usually do not depart more than 1-3 K from the annual mean. In contrast, diurnal temperature variations of 5.1 K and 11.1 K were recorded at elevations of 2670m a.s.l. and 1950m a.s.l., respectively. Short-term climate irregularities, e.g. during periods with prevailing westerly winds, can alter the normal climate conditions considerably and thus are of great significance for plant life. Furthermore, tremendous short-distance variations of the climate are caused by effects of altitude and topography (Richter 2003). [ABSTRACT FROM AUTHOR]

In this paper variability refers to the range of values between particular climate maxima and minima over a period of time (Mitchell 1976). Atmospheric variability in space and time can significantly alter the response of the ecosystem. For instance, comprehensive studies emphasise notable relations of reproduction phenology to climate in tropical rain forests (e.g. Hamann 2004). Three types of relevant spatiotemporal heterogeneities are dicussed in this chapter: Long-term and quasi-periodic oscillations of meteorological conditionsSeasonal changes of selected meteorological parameters (clouds and precipitation), as a supplement to information already presented in Chapter 8The diurnal course of rainfall [ABSTRACT FROM AUTHOR]

The genus Purdiaea is a Neotropical genus of bushes and small trees belonging to the Ericales or heath alliance (Anderberg and Zhang 2002; Ståhl 2004). Purdiaea nutans Planch, is the only species of the genus in continental South America, occurring sporadically on nutrient-poor ridges or highly exposed areas in the Venezuelan Guyana Highlands and in the northern Andes from Colombia to northern Peru (Homeier 2005b; Figs. 19.1, 19.2). In all known localities it appears as isolated tree or shrub within mixed forest stands, except in the Rio San Francisco valley, southern Ecuador (Prov. Zamora-Chinchipe), where the only known forests dominated by P. nutans occur (Bussmann 2001, 2002; Paulsch 2002; Chapter 10.1 in this volume). These Purdiaea forests (Purdiaeaetum nutantis Bussmann 2002) cover about 200ha of upper mountain forest, more than half of which are located within the RBSF (Mandl et al., unpublished data). [ABSTRACT FROM AUTHOR]

There are few studies investigating the different carbon pools and fluxes of tropical soils. Even more restricted is our knowledge of tropical mountain forest soils that cover about 11% of the total tropical forest area (Doumenge et al. 1995). In these ecosystems, decomposition of root and leaf litter is reduced in comparison with lowland tropical forest (Coûteaux et al. 2002). Thus, tropical mountain forests contribute substantially to carbon sequestration in soils. An important component of ecosystem carbon cycling is soil CO2 efflux from the soil to the atmosphere, which results from the activity of soil microbes and root respiration. Globally CO2 efflux amounts to approximately 80 Pg C year-1. Tropical and subtropical evergreen broadleaved forests contribute the largest parts of approx. 22 Pg C year-1 (Raich et al. 2002). Through human activity, especially burning of fossil fuels and conversion of forests into other land use forms, about 7 Pg C enter the atmosphere additionally per year as carbon dioxide. It is assumed that increasing CO2 in the atmosphere are a main cause for higher temperatures observed (Rustad 2001), but as long as it remains unclear how carbon pools and fluxes react on this rise of the temperatures, it is also remains unclear how the global carbon cycle will be altered by climate change in the long term. The objective of this study was to quantify total carbon and nitrogen contents, microbial biomass and total, heterotrophic and root respiration between 1050 m and 3060 m along an altitudinal gradient in natural forests of the research area. Details of the study sites are given by Moser et al. (Chapter 15 in this volume). [ABSTRACT FROM AUTHOR]

In tropical montane forests, the decline of tree size with increasing elevation is a well recognized phenomenon (Lieberman et al. 1996; Raich et al. 1997). The decrease aligns with a continuous species shift from lowland forests, to lower, middle and upper montane forests (Gentry et al. 1995). Leaf area index (LAI) also decreases with elevation from lowland to upper montane forest (Kitayama and Aiba 2002). [ABSTRACT FROM AUTHOR]

Rainfall, litter fall, and organic matter turnover are the major drivers of nutrient fluxes in forest ecosystems. During its passage through the forest, the quantity and chemical composition of water — which enters the forest via rainfall and clouds — changes (Parker 1983). The chemical quality of throughfall and stemflow is controlled by the intensity of rainfall, dry deposition, and soil fertility (Parker 1983; Schaefer and Reiners 1990). The few studies on litter leachate, i.e. the water percolating through the organic layer, in tropical forests indicate that the concentrations of all nutrients increase compared with rainfall and throughfall (e.g., Steinhardt 1979; Hafkenscheid 2000; Wilcke et al. 2001a). In stream water, nutrient concentrations are lower than in litter leachates, except for elements which are released by weathering (Bruijnzeel et al. 1993; McDowell 1998). [ABSTRACT FROM AUTHOR]

Tropical mountain rain forests form biodiversity hotspots for a number of animal and plant taxa (Küper et al. 2004; see Chapter 2 in this volume). Only a few taxa, such as parasitic Hymenoptera, appear not to conform to the general rule of increasing diversity from temperate to tropical regions (Gauld et al. 1992). However, one important component of the animal community, the soil fauna, has rarely been studied in tropical rain forests, especially in mountain regions. The reasons for this presumably are that: (a) soil animals have to be extracted from a 3-dimensional medium by heat or other methodology, (b) there are few keys for determination and (c) a large number of species is still not described. [ABSTRACT FROM AUTHOR]

Rainfall in tropical mountain forests ranges between several hundreds and several thousands of millimeters per year (Cavelier et al. 1997; Bruijnzeel 2001). Many of these forests receive considerable cloud water inputs (Bruijnzeel 2001). During its passage through the forest, the quantity of the water entering the forest with rainfall and clouds changes because of increasing evaporation and transpiration during percolation through the ecosystem (Likens and Bormann 1995; Bruijnzeel 2001). An important water loss is the evaporation of water intercepted in the canopy. Measurements of interception loss of tropical mountain forests also vary over a broad range (Cavelier et al. 1997). The portion of throughfall and stemflow reaching the stream after its passage through the soil depends on water flow paths. The occurrence of rapid interflow is a frequent phenomenon on steep forested hill slopes (Mulholland et al. 1990; Bonell et al. 1998) and is mainly attributable to the high significance of macropores (Buttle and McDonald 2000). Therefore, the assessment of water and element fluxes in the soil requires the due consideration of fast interflow. [ABSTRACT FROM AUTHOR]

Most land plants constitute obligate symbiosis with soil fungi forming mycorrhizae (= fungal roots) in the case of vascular plants and mycorrhiza-like associations in the case of liverworts and hornworts. The fungi significantly improve nutrient uptake in the mostly nutrient-limited conditions in nature and supply minerals to the plants (Read and Perez-Moreno 2003). Glomeromycota, Hymenomycetes of Basidiomycota, Pezizales, some Leotiales, and other Ascomycota are the most important mycorrhizal fungi forming structurally distinctive associations, as determined by evolution and environmental constraints (Kottke 2002; Brundrett 2004). The tropical mountain rain forest in South Ecuador is not only exceptionally diverse in tree species, but also a hotspot for ericads, orchids, ferns, and liverworts (see Chapters 2 and 10.1 in this volume). Diverse mycorrhizal associations were, therefore, expected. Very restricted information was previously published from similar forests (Alexander and Högberg 1986). We, therefore, started with morphological and ultrastructural investigations of the mycorrhizae of the 220 tree species, the ericads, some abundant and mostly endemic, epiphytic pleurothallid orchids, and some epiphytic ferns, and we also investigated some mycorrhiza-like associations of liverworts. Here we consider the mycorrhizal state and the occurrence of the distinct mycorrhizal associations along the altitudinal and horizontal gradients, and we compile a number of new structural features. [ABSTRACT FROM AUTHOR]

In the literature, it is well documented that there are systematic changes in soil properties and thus in soil fertility along altitudinal gradients in tropical mountains (e.g., Marrs et al. 1988; Grieve et al. 1990; Schrumpf et al. 2001). Grieve et al. (1990) reported increasing soil organic matter concentrations along an altitudinal transect from 100 m to 2600 m a.s.l. in Costa Rica. Furthermore, it has been reported for several forests that C/N ratios increase with increasing altitude (Edwards and Grubb 1982; Schrumpf et al. 2001). Mineralization rates are negatively correlated with the C/N ratio and the lignin and polyphenol concentrations (Tian et al. 1995). Consequently, N mineralization and nitrification rates decrease with increasing altitude (Marrs et al. 1988). For the study area in Ecuador, it was shown that the pH and N concentrations decrease and C/N ratio and hydromorphic properties increase with increasing altitude between 1850 m and 3050 m a.s.l. in a previous study (Schrumpf et al. 2001). [ABSTRACT FROM AUTHOR]

The altitudinal gradient of climate is a major driver for abiotic and biotic processes in the study area. Hence, a set of meteorological stations was established along an altitudinal gradient in the RBSF area (Table 8.1). The observations are representative for the climate outside the forest, which gives a meteorological background signal for micrometeorological measurements within the forest. The aim of the current Chapter is to present an inventory of the meteorological gradients in the central study area. Climatic irregularities and their impact are described in Chapters 20\2-23. [ABSTRACT FROM AUTHOR]

As discussed by Fiedler and Beck (Chapter 6 in this volume) gradient analysis is a powerful tool for the investigation of an ecosystem. The knowledge of the RBSF that has arisen from gradient analysis is presented in the following chapters. This chapter, however, attempts to introduce the reader to the strategy of the ecosystem study, discussing the features which can be revealed by identifying appropriate gradients. One basic requisite of the joint venture was to concentrate all projects on the same core research area, the RBSF in order to produce coherent data (Fig. 7.1). Satellite areas or monitoring stations were established to address questions of supraregional relevance. On that rationale four gradients were followed, two of which are natural gradients based on climatic factors while the other two result from human activities. [ABSTRACT FROM AUTHOR]

‘Megadiversity' originated as a term in the context of biodiversity conservation in the late 1980s (Mittermeier et al. 2004). It refers to countries with an extremely high level of species richness, usually found in the tropical realm, one or two orders higher in magnitude than in most temperate zone countries. In many ways countries or areas of megadiversity coincide with the slightly longer-established concept of biodiversity hotspots (Myers et al. 2000; Brummitt and Lughadha 2003; see Chapter 2 in this volume). Unlike the concept of hotspots, megadiversity also attempts to take into account degrees of endemism, phylogenetic relatedness, and other measures of diversity applied for identifying biodiversity hotspots as opposed to pure numbers of species or taxa per unit area. More than any academic differentiation, however, the term megadiversity was recently taken up and promoted at the political level, particularly under the Convention of Biological Diversity (CBD), as well as the Convention on International Trade in Endangered Species of Fauna and Flora (CITES). Following the original meeting in Cancun, Mexico, in February 2002, 15 countries formed a group of ‘Like-Minded Megadiverse Countries' (LMMC) as a forum to address the specific challenges for biodiversity conservation and sustainable use faced by countries with disproportional high levels of biodiversity (‘Cancun declaration 2002'). Later joined by Australia and the USA, this informal group of countries comprises many but by no means all of the recognized global biodiversity hotspots. [ABSTRACT FROM AUTHOR]

Natural ecosystems are usually highly complex. They are built up by a multitude of organisms which interact with each other as well as with their abiotic (i.e. physical and chemical) environment. The more kinds of organisms thrive in an ecosystem, the more complex is its internal structure. For example, food web complexity is a function of the direct and indirect interactions between organisms, and this increases in a non-linear manner with the number of players. Food web complexity, in turn, affects emergent properties of ecosystems such as water and nutrient cycles, or the dynamics and resilience of the system in an unpredictable and changing environment. Accordingly, understanding the function of natural ecosystems becomes ever more challenging with increasing species richness. [ABSTRACT FROM AUTHOR]

"Deforestation" in this chapter is used according to the FAO (2001) definition: it is the conversion of forest to another land use or the long-term reduction of the tree canopy cover below the minimum 10% threshold. This implies that areas where trees have been removed as a result of harvesting or logging are not considered as "deforestation". Even if the structure or function of a forest is heavily disturbed by harvesting operations, the stand remains a forest as long as it has a tree canopy cover of more than 10% or is expected to regenerate naturally or artificially in the long run. So "deforestation" in the sense of the FAO definition does not incorporate the degradation of forests included in some other definitions, e.g. Myers (1994). Correspondingly the replacement of old-growth forests by plantations or their temporary use by shifting cultivators is not considered as destruction or deforestation. Only a complete change of land use or the destruction of forest cover which prevents its recovery to more than 10% crown cover enters the FAO statistics as "deforestation" or "forest loss". [ABSTRACT FROM AUTHOR]