Exploring urban adaptation practice : Focus on co-production and multi-level governance
Carter, J. ; Lefebre, Filip ; Connelly, Angela ; Terenzi, Alberto ; Mendizabal, Maddalen ; Dumonteil, Margaux ; Sips, K. ; Pansaerts, Resi ; Feliu, Efrén ; Verstraeten, G. ; Coninx, I. - \ 2017
In: Full Programme: ECCA (European Conference on Climate Adaptation) 2017. - - p. 267 - 270.
co-production - collaboration - citizen participation - multi-level governance - science-policy interface - financing constraints - european cities
A model-based approach to studying changes in compositional heterogeneity
Baeten, L. ; Warton, D. ; Calster, H. van; Frenne, P. De; Verstraeten, G. ; Bonte, D. ; Bernhardt-Romermann, M. ; Cornelis, R. ; Decocq, G. ; Eriksson, O. ; Hommel, P.W.F.M. - \ 2014
Methods in Ecology and Evolution 5 (2014)2. - ISSN 2041-210X - p. 156 - 164.
with-standards forest - biotic homogenization - beta-diversity - plant-communities - deciduous forest - vegetation - turnover - dissimilarity - nestedness - dispersion
1. Non-random species loss and gain in local communities change the compositional heterogeneity between communities over time, which is traditionally quantified with dissimilarity-based approaches. Yet, dissimilarities summarize the multivariate species data into a univariate index and obscure the species-level patterns of change, which are central to understand the causes and consequences of the community changes. 2. Here, we propose a model-based approach that looks for species-level effects of time period and construct a multiple-site metric as a sum across species to test the consistency of the individual species responses. Species fall into different response types, showing how they influence the changes in community heterogeneity. 3. In a comparison with other multiple-sitemetrics, we illustrate the properties of our method and the differences and similarities with other approaches. For instance, ourmetric estimates the total variation in a community data set based on species-level contributions, not the compositional dissimilarities between particular sites. Similar to some other approaches, we can distinguish between heterogeneity derived from turnover or richness differences. 4. Our approach was applied to a set of 23 forest understorey resurvey studies spread across Europe. We show the species gains and lossesmay as well decrease or increase levels of community heterogeneity. Although species occurrences and communities have not changed in a consistent way along continental-scale environmental gradients such as climatic conditions, several species shifted in a similar way across the different data sets. 5. Testing the significance of shifts in species prevalence over time to infer corresponding changes in the compositional heterogeneity among sites provides a very intuitive tool for community resurvey studies. The main strengths of our framework are the explicit consideration of the relative roles of species gains and losses and the straightforward generalization to different sets of hypotheses related to community changes. Key-words: biodiversity, community composition, biotic homogenization, binomial deviance, dissimilarity, beta diversity,multivariate analysis,meta-analysis, forest understorey
Microclimate moderates plant responses to macroclimate warming
Frenne, P. De; Rodríguez-Sánchez, F. ; Coomes, D. ; Baeten, L. ; Verstraeten, G. ; Hommel, P.W.F.M. - \ 2013
Proceedings of the National Academy of Sciences of the United States of America 110 (2013)46. - ISSN 0027-8424 - p. 18561 - 18565.
recent climate-change - forest - vegetation - communities - ecosystem - scale - debt
Recent global warming is acting across marine, freshwater, and terrestrial ecosystems to favor species adapted to warmer conditions and/or reduce the abundance of cold-adapted organisms (i.e., “thermophilization” of communities). Lack of community responses to increased temperature, however, has also been reported for several taxa and regions, suggesting that “climatic lags” may be frequent. Here we show that microclimatic effects brought about by forest canopy closure can buffer biotic responses to macroclimate warming, thus explaining an apparent climatic lag. Using data from 1,409 vegetation plots in European and North American temperate forests, each surveyed at least twice over an interval of 12–67 y, we document significant thermophilization of ground-layer plant communities. These changes reflect concurrent declines in species adapted to cooler conditions and increases in species adapted to warmer conditions. However, thermophilization, particularly the increase of warm-adapted species, is attenuated in forests whose canopies have become denser, probably reflecting cooler growing-season ground temperatures via increased shading. As standing stocks of trees have increased in many temperate forests in recent decades, local microclimatic effects may commonly be moderating the impacts of macroclimate warming on forest understories. Conversely, increases in harvesting woody biomass—e.g., for bioenergy—may open forest canopies and accelerate thermophilization of temperate forest biodiversity.
Changing sediment dynamics due to natural reforestation in the Dragonja catchment, S.W. Slovenia
Keesstra, S.D. ; Dam, O. van; Verstraeten, G. ; Huissteden, J. van - \ 2009
Catena 78 (2009)1. - ISSN 0341-8162 - p. 60 - 71.
coon creek basin - land-use changes - floodplain sedimentation - agricultural catchments - gully erosion - soil-erosion - river - australia - delivery - storage
Under the influence of socio¿economic changes in many regions in Europe, a trend of decreasing agricultural activity has been observed since the Second World War. The resulting reforestation profoundly changes water and sediment supply to river channels, deposition rates on the floodplains and erosion rates on the hillslopes. We studied these changes in the 91 km2 Dragonja catchment in southwestern Slovenia. With the spatially distributed erosion and sediment delivery model WATEM/SEDEM, the hillslope sediment delivery to the river channel was calculated on the basis of parameters (soil and precipitation parameters, a DEM and land use) measured in the field and laboratory in 2002 and land use maps based on aerial photographs from 1954, 1975, 1985 and 1994. For two independent calibrations WATEM/SEDEM modelled a sharp decline of 69% in total hillslope sediment delivery from 1954 to 2002. As the sub-catchments Rokava and Upper-Dragonja did not reforest in the same way, the sediment yield response is different as well. Separate calculations show the same reduction (45%) in sediment yield from 1954 to 1975. After 1975 the sediment yield was stable in the Rokava sub-catchment. In the Upper-Dragonja the trend continued, to a total reduction of 76% of sediment outflow since 1954. The sources of fine sediment were determined by analysing the hysteresis of the discharge waves, and the suspended sediment texture. The sediment that leaves the catchment originates from three sources: hillslopes, erosional bedrock banks and sedimentary riverbanks. The analysis of the suspended sediment texture suggests that during a discharge wave the suspended sediment originates predominantly from the hillslopes. During low stage the sparse sediment in the water column largely originates from large bedrock banks. The sedimentary riverbanks are not an important source of suspended sediment