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The chapter starts with a discussion of general patterns and processes in terrestrial ecosystems, including the impacts of climate change in relation to productivity, phenology, trophic matches and mismatches, range shifts and biodiversity. Climate impacts on specific ecosystem types-forests, grasslands, heathlands, and mires and peatlands-are then discussed in detail. The chapter concludes by discussing links between changes in inland ecosystems and the wider North Sea system. Future climate change is likely to increase net primary productivity in the North Sea region due to warmer conditions and longer growing seasons, at least if summer precipitation does not decrease as strongly as projected in some of the more extreme climate scenarios. The effects of total carbon storage in terrestrial ecosystems are highly uncertain, due to the inherent complexity of the processes involved. For moderate climate change, land use effects are often more important drivers of total ecosystem carbon accumulation than climate change. Across a wide range of organism groups, range expansions to higher latitudes and altitudes and changes in phenology have occurred in response to recent climate change. For the range expansions, some studies suggest substantial differences between organism groups. Habitat specialists with restricted ranges have generally responded very little or even shown range contractions. Many of already threatened species could be particularly vulnerable to climate change. Overall, effects of recent climate change on terrestrial ecosystems within the North Sea region are still limited.

CopyrightOther than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. IntroductionIn 2004 a large, more than 4 m deep building excavation was made in Wageningen ( Fig. 1) in order to prepare the foundation of a new university building (so-called Forum Building). Dr Monique Heijmans of the Nature Conservation and Plant Ecology Group of Wageningen University informed the first author about a peat deposit, covered by a lake deposit, as it was exposed in the profiles of the building excavation. The Wageningen-Forum site is situated in a former Saalian tongue basin. During the Weichselian this basin was filled in with alternating fluvial meltwater deposits from the ice-pushed ridges and aeolian cover sands. During relatively humid phases drain water from the ice-pushed ridges caused seepage in the basin and therefore lakes and fens could develop in the depressions in the landscape. Lake sediments and peat deposits were overblown with sand during periods of aeolian activity. The Forum site shows an example of well-preserved peat and lake sediments covered by aeolian sand. In the same tongue basin northwest of Veenendaal a peat deposit of Allerød AbstractBotanical microfossils, macroremains and oribatid mites of a Weichselian interstadial deposit in the central Netherlands point to a temporary, sub-arctic wetland in a treeless landscape. Radiocarbon dates and OSL dates show an age between ca. 54.6 and 46.6 ka cal BP. The vegetation succession, starting as a peat-forming wetland that developed into a lake, might well be linked with a Dansgaard-Oeschger climatic cycle. We suggest that during the rapid warming at the start of a D-O cycle, relatively low areas in the landscape became wetlands where peat was formed.During the more gradual temperature decline that followed, evaporation diminished; the wetlands became inundated and lake sediments were formed. During subsequent sub-arctic conditions the interstadial deposits were covered with wind-blown sand. Apart from changes in effective precipitation also the climate-related presence and absence of permafrost conditions may have played a role in the formation of the observed sedimentological sequence from sand to peat, through lacustrine sediment, with coversand on top. The Wageningen sequence may correspond with D-O event 12, 13 or 14. Some hitherto not recorded microfossils were described and illustrated.Keywords: Dansgaard-Oeschger cycles, macrofossils, non-pollen palynomorphs, Oribatida, pollen...

Assessment of land use related greenhouse gas (GHG) emissions on larger spatial scales is usually achieved by modelling. Surface flux measurements are expensive and measurement locations too widely scattered to serve as spatially reliable flux estimates. Here we assess CO2 and CH4 fluxes from wetland nature reserves in the Dutch province of Drenthe, using the PEATLAND-VU model. Since surface flux observations in the province are absent and cannot be obtained in a short (<1 year) time frame, we extrapolated model validation from elsewhere to the research area. In this way a cost-effective methodology is developed for landuse-related greenhouse gas emission assessments, which can be applied by local governments at a subnational scale.Nature development and restoration in the Netherlands involves usually the restoration of high water tables in former agricultural areas and extensivation or abandonment of agricultural activities. Wet peat soils are known to emit considerable quantities of CH4, while drained agricultural soils emit CO2 from decomposition of the soil organic matter. Therefore, these landuse changes may affect GHG emissions and an assessment of their effects is useful for environmental policy.The PEATLAND-VU Model was used to simulate the CH4 and CO2 emissions for the years 2005-2007 and for May/June 2008. Previous field validation of the model elsewhere was checked for local validity with CH4 and CO2 flux measurements in short field campaigns in May/June 2008, at two locations, Visvliet and Balloërveld. These sites represent respectively eutrophic and oligotrophic peat and peaty soils, and showed large differences in fluxes. These flux differences were simulated correctly by the model by adapting the vegetation net primary production and methane oxidation parameters. Next, model simulations were run for eight combinations of vegetation and soil type. Using the simulated fluxes and the areal extent of the soil combinations, a GIS-based upscaling over all nature reserves was made.This study shows that river valley floors with mesotrophic and eutrophic peat soils dominate the greenhouse fluxes of the area. CH4 fluxes are high in wet terrain, while the CO2 fluxes are high when water table is lower. The fluxes from oligotrophic peat soils are comparatively low. Nature development can contribute to a decrease of the total greenhouse gas flux from peat soils and to conservation of soil organic matter.

Abstract. Peat decomposition in managed peatlands is responsible for a decrease of 0.52 GtC yr−1 in global carbon stock and is strongly linked to drainage to improve the agricultural bearing capacity, which increases aeration of the soil. Microbial aerobic decomposition is responsible for the bulk of the net CO2 emission from the soil and could be reduced by wetting efforts or minimizing drainage. However, the effects of rewetting efforts on microbial respiration rate are largely unknown. We aimed to obtain more insight in these rewetting effects and measured them for 1 year for two dairy farming peatlands where submerged drainage subsurface irrigation (SDSI) was tested against a control situation. With a modelling approach, we explored the effects of rewetting under different weather conditions, water management strategies (raising ditch water levels and SDSI) and hydrological settings. We introduced a methodology to estimate potential aerobic microbial respiration rate as measure for peat decomposition in managed peatlands, based on potential respiration rate curves for soil temperature and water filled pore space (WFPS). Rewetting with SDSI resulted in higher summer groundwater levels, soil temperatures and WFPS. SDSI reduced net ecosystem production (NEP) with 1.27 ± 0.39 kg CO2 m−2 yr−1 (83 %) and 0.78 ± 0.37 kg CO2 m−2 yr−1 (35 %) for Assendelft and Vlist respectively. With the process based modelling approach we found that raising ditch water levels always reduces peat respiration rates. Furthermore, we found that the application of SDSI reduces yearly peat respiration rates in environments in a dry year and/or with downward hydrological fluxes, and increases peat respiration rates in a wet year and/or when upward groundwater fluxes are present. Moreover, combining SDSI with high ditch water levels or pressurizing SDSI systems will further reduce peat respiration rates. We highly recommend to use a process-based approach based on temperature and WFPS soil conditions to determine effectivities of rewetting efforts over empirical relationships between average groundwater level and NEP. Such a more process based approach allows to distinguish between groundwater levels raised by SDSI and ditch water levels. When this is not possible, we recommend using mean summer groundwater level instead of mean annual groundwater level as a proxy to estimate NEP. Such relations between mean groundwater levels and NEP need to be corrected for situations with SDSI.