State of the art review on climate change impacts on natural ecosystems and adaptation

Climate change has become unavoidable and the Netherlands has started to adapt the water systems and coastal defense to reduce vulnerability to the effects of climate change. These strategies to make the Netherlands climate-proof will also have its impact on nature and ecosystem functioning, in addition to the direct impacts of climate change. This report provides a state-of-the-art review of national and international research with respect to climate change impacts and adaptation, relevant to natural ecosystems in the Netherlands. This review is intended to serve as a reference of current available knowledge and will assist in programming new research required for climate-proofing the Netherland

Effects of litters with different concentrations of phenolics on the competition between Calluna vulgaris and Deschampsia flexuosa

We hypothesized that the outcome of competition between ericaceous plants and grasses is strongly affected by the concentrations of phenolics in the litter that they produce. To test the effect of phenolic-rich litter on soluble soil nitrogen concentrations, plant nitrogen uptake and inter-specific competition, we conducted a greenhouse experiment with the shrub Calluna vulgaris and the grass Deschampsia flexuosa and their leaf litters. Two litters of C. vulgaris were used, with equal nitrogen concentration but different (high and low) concentrations of total phenolics. The D. flexuosa leaf litter contained lower concentrations of phenolics, but higher concentrations of nitrogen than the C. vulgaris litters. The plants were grown in monocultures and in mixed cultures. Inorganic and dissolved organic nitrogen were measured monthly during the experiment. After four months, we measured above- and belowground biomass and the nutrient concentrations in above- and belowground plant parts. In monocultures, C. vulgaris produced more shoot and root biomass on its own litter than with no litter. Growth of Calluna was reduced on grass litter. D. flexuosa plants produced most biomass on their own litter type, whether in monocultures or in mixed cultures. Addition of Calluna litter stimulated the growth of D. flexuosa both in monoculture and in mixtures. The grass plants outcompeted Calluna both on shrub litter and on grass litter but not when grown without litter. The two C. vulgaris litter types that differed in their concentration of phenolics did not differ in their effects on the competition between the two species or on the production of inorganic and dissolved organic nitrogen. We conclude that the nitrogen content of the litter is more important as a plant feature driving competition between shrubs and grasses than the concentrations of phenolic

Field Simulation of Global Change: Transplanting Northern Bog Mesocosms Southward

A large proportion of northern peatlands consists of Sphagnum-dominated ombrotrophic bogs. In these bogs, peat mosses (Sphagnum) and vascular plants occur in an apparent stable equilibrium, thereby sustaining the carbon sink function of the bog ecosystem. How global warming and increased nitrogen (N) deposition will affect the species composition in bog vegetation is still unclear. We performed a transplantation experiment in which mesocosms with intact vegetation were transplanted southward from north Sweden to north-east Germany along a transect of four bog sites, in which both temperature and N deposition increased. In addition, we monitored undisturbed vegetation in control plots at the four sites of the latitudinal gradient. Four growing seasons after transplantation, ericaceous dwarf shrubs had become much more abundant when transplanted to the warmest site which also had highest N deposition. As a result ericoid aboveground biomass in the transplanted mesocosms increased most at the southernmost site, this site also had highest ericoid biomass in the undisturbed vegetation. The two dominant Sphagnum species showed opposing responses when transplanted southward; Sphagnum balticum height increment decreased, whereas S. fuscum height increment increased when transplanted southward. Sphagnum production did not differ significantly among the transplanted mesocosms, but was lowest in the southernmost control plots. The dwarf shrub expansion and increased N concentrations in plant tissues we observed, point in the direction of a positive feedback toward vascular plant-dominance suppressing peat-forming Sphagnum in the long term. However, our data also indicate that precipitation and phosphorus availability influence the competitive balance between Sphagnum, dwarf shrubs and graminoids

Release of CO2 and CH4 from lakes and drainage ditches in temperate wetlands

Shallow fresh water bodies in peat areas are important contributors to greenhouse gas fluxes to the atmosphere. In this study we determined the magnitude of CH4 and CO2 fluxes from 12 water bodies in Dutch wetlands during the summer season and studied the factors that might regulate emissions of CH4 and CO2 from these lakes and ditches. The lakes and ditches acted as CO2 and CH4 sources of emissions to the atmosphere; the fluxes from the ditches were significantly larger than the fluxes from the lakes. The mean greenhouse gas flux from ditches and lakes amounted to 129.1 ± 8.2 (mean ± SE) and 61.5 ± 7.1 mg m-2 h-1 for CO2 and 33.7 ± 9.3 and 3.9 ± 1.6 mg m-2 h-1 for CH4, respectively. In most water bodies CH4 was the dominant greenhouse gas in terms of warming potential. Trophic status of the water and the sediment was an important factor regulating emissions. By using multiple linear regression 87% of the variation in CH4 could be explained by PO4 3- concentration in the sediment and Fe2+ concentration in the water, and 89% of the CO2 flux could be explained by depth, EC and pH of the water. Decreasing the nutrient loads and input of organic substrates to ditches and lakes by for example reducing application of fertilizers and manure within the catchments and decreasing upward seepage of nutrient rich water from the surrounding area will likely reduce summer emissions of CO2 and CH4 from these water bodie

Caribbean delight: Moving beyond the sustainability discourse in tourism

In the tourism literature a lot of attention is paid to different approaches towards tourism development, especially when it comes to developing countries. Often it is argued that it is necessary to come to a sustainable approach, whereby it is stressed that attention should be paid to the way tourism organizations influence (and are influenced by) the natural environment as well as the cultural, and economical context in which they are situated. Although the debates on sustainable forms of tourism development are a positive direction for the tourism field, we will argue in this paper that these debates will not really contribute to the progress of the field as long as there is a lack of local accounts of actors in such tourism destinations. By presenting empirical data from Belize and the Dominican Republic, the aim is to move beyond the dominant ‘sustainability discourse’ in the field of tourism in which mass-tourism is per definition ‘bad’ and small-scale tourism is ‘good’, and gain an insight into what is actually going on at the micro level. En la literatura del turismo se presta mucha atención a los diferentes acercamientos al desarrollo del turismo, especialmente cuando nos referimos a países en vías de desarrollo. Se sostiene a menudo que es necesario un enfoque basado en la sostenibilidad, por lo cual se remarca que se preste especial atención a cómo influyen las organizaciones de turismo (y cómo son influenciadas) tanto por el entorno natural como el cultural y el económico en el que se sitúan. Aunque los debates sobre las formas sostenibles de desarrollo turístico son un camino positivo para el sector turístico, en este artículo analizaremos porqué estos debates no contribuirán realmente al progreso del sector mientras haya una carencia de agentes locales de tales destinos turísticos. Presentando datos empíricos sobre Belice y la República Dominicana, el objetivo es ir más allá del dominante discurso sobre la sostenibilidad en el ámbito turístico, en el que el turismo de masas es por definición “malo” y el turismo a menor escala es “bueno”, y hacer una incursión en lo que realmente está sucediendo a nivel micro

Caribbean Delight: Moving Beyond the Sustainability Discourse in Tourism

In the tourism literature a lot of attention is paid to different approaches towards tourism development, especially when it comes to developing countries. Often it is argued that it is necessary to come to a sustainable approach, whereby it is stressed that attention should be paid to the way tourism organizations influence (and are influenced by) the natural environment as well as the cultural, and economical context in which they are situated. Although the debates on sustainable forms of tourism development are a positive direction for the tourism field, we will argue in this paper that these debates will not really contribute to the progress of the field as long as there is a lack of local accounts of actors in such tourism destinations. By presenting empirical data from Belize and the Dominican Republic, the aim is to move beyond the dominant ‘sustainability discourse’ in the field of tourism in which mass-tourism is per definition ‘bad’ and small-scale tourism is ‘good’, and gain an insight into what is actually going on at the micro level. En la literatura del turismo se presta mucha atención a los diferentes acercamientos al desarrollo del turismo, especialmente cuando nos referimos a países en vías de desarrollo. Se sostiene a menudo que es necesario un enfoque basado en la sostenibilidad, por lo cual se remarca que se preste especial atención a cómo influyen las organizaciones de turismo (y cómo son influenciadas) tanto por el entorno natural como el cultural y el económico en el que se sitúan. Aunque los debates sobre las formas sostenibles de desarrollo turístico son un camino positivo para el sector turístico, en este artículo analizaremos porqué estos debates no contribuirán realmente al progreso del sector mientras haya una carencia de agentes locales de tales destinos turísticos. Presentando datos empíricos sobre Belice y la República Dominicana, el objetivo es ir más allá del dominante discurso sobre la sostenibilidad en el ámbito turístico, en el que el turismo de masas es por definición “malo” y el turismo a menor escala es “bueno”, y hacer una incursión en lo que realmente está sucediendo a nivel micro

Peatlands and the carbon cycle: from local processes to global implications - a synthesis

Peatlands cover only 3% of the Earth's land surface but boreal and subarctic peatlands store about 15-30% of the world's soil carbon ( C) as peat. Despite their potential for large positive feedbacks to the climate system through sequestration and emission of greenhouse gases, peatlands are not explicitly included in global climate models and therefore in predictions of future climate change. In April 2007 a symposium was held in Wageningen, the Netherlands, to advance our understanding of peatland C cycling. This paper synthesizes the main findings of the symposium, focusing on (i) small-scale processes, (ii) C fluxes at the landscape scale, and (iii) peatlands in the context of climate change. The main drivers controlling most are related to some aspects of hydrology. Despite high spatial and annual variability in Net Ecosystem Exchange ( NEE), the differences in cumulative annual NEE are more a function of broad scale geographic location and physical setting than internal factors, suggesting the existence of strong feedbacks. In contrast, trace gas emissions seem mainly controlled by local factors. Key uncertainties remain concerning the existence of perturbation thresholds, the relative strengths of the CO2 and CH4 feedback, the links among peatland surface climate, hydrology, ecosystem structure and function, and trace gas biogeochemistry as well as the similarity of process rates across peatland types and climatic zones. Progress on these research areas can only be realized by stronger co-operation between disciplines that address different spatial and temporal scales