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Staes J.,University of Antwerp | Broekx S.,Flemish Institute for Technological Research | Van Der Biest K.,University of Antwerp | Vrebos D.,University of Antwerp | And 8 more authors.
Ecosystem Services | Year: 2017

Ecological networks of protected areas are critical elements to protect biodiversity. To achieve a minimal performance of such networks, measures and investments are necessary for nature restoration and management. The concept of ecosystem service (ES) can provide additional arguments for investments in ecological networks. However, ES delivery processes are embedded in a complex array of ecological processes and there is a need to cope with this complexity in a pragmatic manner. As many assessment studies have already been criticized for using oversimplified indicators, too much pragmatism may foreclose credibility and acceptance of ES assessments. Therefore, a cascade ES modelling approach was developed that incorporated ecological processes, multiple off-site effects, feedbacks and trade-off mechanisms through shared variables. The assessment focused on which services the existing network delivers and how these services are influenced after realization of site specific conservation objectives. © 2017 Elsevier B.V.


Vander Mijnsbrugge K.,Research Institute for Nature and Forest | Vander Mijnsbrugge K.,Agency for Nature and Forest | Le Clercq R.,Research Institute for Nature and Forest | Michiels B.,Research Institute for Nature and Forest
Plant Systematics and Evolution | Year: 2016

Ulmus laevis Pallas is a rare and endangered tree species in the northern part of Belgium, restricted to a minimal amount of natural populations that mainly consist of a strongly reduced number of individuals. Probably isolated for several generations, random phenotypic variation in the strongly declined populations can be hypothesised. We analysed U. laevis trees grown in a field trial with a single-tree-plot design (completely randomised). The plants were vegetatively propagated through cuttings from nearly all known natural relict populations in Flanders. We analysed three short-shoot leaves from different ramets from different genotypes from eleven natural populations. Leaf size and shape variables were computed using landmark and procruste methods. We visualised the variability in leaf morphology in a principal component analysis (PCA) including shape, size, and categorical morphological variables. The variance structure of the morphological variables was studied applying mixed modelling methods. The overall PCA distinguished two deviating natural populations. The Zandhoven population showed a deviating simple leaf margin toothing, correlated with larger numbers of split secondary veins. The Halle population is characterised by absence of pubescence at the lower side of the leaves. Both relict populations with deviating morphological leaf characteristics may point to an ecotype evolution putatively due to isolation combined with greatly diminished population sizes. The variance structure analysis of individual leaf variables showed that the deviating categorical leaf characters are under stronger genetic control (specialist characters) compared to the more plastic variables. © 2015, The Author(s).


De Kort H.,Catholic University of Leuven | Vander Mijnsbrugge K.,Research Institute for Nature and Forest | Vander Mijnsbrugge K.,Agency for Nature and Forest | Vandepitte K.,Catholic University of Leuven | And 3 more authors.
Journal of Evolutionary Biology | Year: 2016

Both traits and the plasticity of these traits are subject to evolutionary change and therefore affect the long-term persistence of populations and their role in local communities. We subjected clones from 12 different populations of Alnus glutinosa, located along a latitudinal gradient, to two different temperature treatments, to disentangle the distribution of genetic variation in timing of bud burst and bud burst plasticity within and among genotypes, populations, and regions. We calculated heritability and evolvability estimates for bud burst and bud burst plasticity and assessed the influence of divergent selection relative to neutral drift. We observed higher levels of heritability and evolvability for bud burst than for its plasticity, whereas the total phenological heritability and evolvability (i.e. combining timing of bud burst and bud burst plasticity) suggest substantial evolutionary potential with respect to phenology. Earlier bud burst was observed for the low-latitudinal populations than for the populations from higher latitudes, whereas the high-latitudinal populations did not show the expected delayed bud burst. This countergradient variation can be due to evolution towards increased phenological plasticity at higher latitudes. However, because we found little evidence for adaptive differences in phenological plasticity across the latitudinal gradient, we suggest differential frost tolerance as the most likely explanation for the observed phenological patterns in A. glutinosa. © 2016 European Society for Evolutionary Biology.


Vander Mijnsbrugge K.,Research Institute for Nature and Forest | Vander Mijnsbrugge K.,Agency for Nature and Forest | Turcsan A.,Research Institute for Nature and Forest | Turcsan A.,Corvinus University of Budapest | Michiels B.,Research Institute for Nature and Forest
Plant Systematics and Evolution | Year: 2016

Flushing in spring marks an important adaptive process in a tree’s growth cycle. We studied bud burst in three provenances of a common small tree Frangula alnus Mill., originating from Italy, Belgium and Sweden. We observed timing of bud burst and leaf senescence in a common garden, and timing and duration of bud burst in greenhouse conditions (cuttings) with different temperature regimes, all located in Belgium. The early bud burst response of the southern European provenance together with the later leaf senescence compared to the local provenance indicated population differentiation that may, at least partly, be driven by local adaptation to a longer growing season. The duration of the process was longer in the cold greenhouse compared to the local provenance, whereas it responded similar as the local provenance in the warm greenhouse, suggesting adaptation to warmer conditions. Unexpectedly, the northern European provenance expressed a plastic reaction to warmer temperatures in the field trial and in the greenhouse conditions flushing in both cases earlier than the local provenance. The duration of the process in the warm greenhouse compared to the local provenance was shorter, whereas in the cold greenhouse it was similar. This result again suggested that not only the onset, but also the duration of the bud burst process was a plastic reaction to the warmer conditions compared to its site of origin. Together, our results suggest two mechanisms driving bud burst in F. alnus provenances, a co-gradient and a counter-gradient variation depending on the latitude of origin. © 2015, Springer-Verlag Wien.


Turcsan A.,Research Institute for Nature and Forest | Turcsan A.,Corvinus University of Budapest | Turcsan A.,University of West Hungary | Steppe K.,Ghent University | And 5 more authors.
Frontiers in Plant Science | Year: 2016

More severe summer droughts are predicted for mid-latitudes in Europe. To evaluate the impact on forest ecosystems and more specifically on forest regeneration, we studied the response to summer drought in oak seedlings (Quercus petraea). Acorns were collected from different mother trees in three stands in Belgium, sown in pots and grown in non-heated greenhouse conditions. We imposed drought on the seedlings in early summer by first watering the pots to saturation and then stopping any watering. Weight of the pots and stomatal conductance were regularly measured. Re-watering followed this drought period of 5 weeks. Height of the seedlings and apical bud development were observed. Stomatal resistance increased toward the end of the experiment in the drought-treated group and was restored after re-watering. The seedlings from the drought treatment displayed a higher probability to produce additional shoot growth after re-watering (p ≤ 0.05). A higher competition for water (two plants per pot) increased this chance. Although this chance was also higher for smaller seedlings, the actual length of the extra growth after re-watering was higher for larger seedlings (p ≤ 0.01). Both in the drought-treated and in the control group the autochthonous provenance growing on a xeric site produced less extra shoots compared to the two other provenances. Finally, stressed plants showed less developed apical buds compared to the control group after re-watering, suggesting a phenological effect on the growth cycle of oaks (p ≤ 0.0001). The higher chance for an extra shoot growth after the drought period can be considered as a compensation for the induced growth arrest during the drought period. © 2016, Turcsán, Steppe, Sárközi, Erdélyi, Missoorten, Mees and Mijnsbrugge.


De Kort H.,Catholic University of Leuven | Vandepitte K.,Catholic University of Leuven | Mergeay J.,Research Institute for Nature and Forest | Mijnsbrugge K.V.,Research Institute for Nature and Forest | And 2 more authors.
Heredity | Year: 2015

The evaluation of the molecular signatures of selection in species lacking an available closely related reference genome remains challenging, yet it may provide valuable fundamental insights into the capacity of populations to respond to environmental cues. We screened 25 native populations of the tree species Frangula alnus subsp. alnus (Rhamnaceae), covering three different geographical scales, for 183 annotated single-nucleotide polymorphisms (SNPs). Standard population genomic outlier screens were combined with individual-based and multivariate landscape genomic approaches to examine the strength of selection relative to neutral processes in shaping genomic variation, and to identify the main environmental agents driving selection. Our results demonstrate a more distinct signature of selection with increasing geographical distance, as indicated by the proportion of SNPs (i) showing exceptional patterns of genetic diversity and differentiation (outliers) and (ii) associated with climate. Both temperature and precipitation have an important role as selective agents in shaping adaptive genomic differentiation in F. alnus subsp. alnus, although their relative importance differed among spatial scales. At the 'intermediate' and 'regional' scales, where limited genetic clustering and high population diversity were observed, some indications of natural selection may suggest a major role for gene flow in safeguarding adaptability. High genetic diversity at loci under selection in particular, indicated considerable adaptive potential, which may nevertheless be compromised by the combined effects of climate change and habitat fragmentation.


Vander Mijnsbrugge K.,Research Institute for Nature and Forest | Vander Mijnsbrugge K.,Agency for Nature and Forest | Depypere L.,Ghent University | Michiels B.,Research Institute for Nature and Forest | De Cuyper B.,Research Institute for Nature and Forest
Basic and Applied Ecology | Year: 2016

Natural populations of woody species are adapted to local growth conditions. Non-local provenances may sense the difference between the local environment and the site conditions at their origin. To study the impact of provenance selection of planting stock in (re)forestation and landscape plantings, the variation in the adaptive traits bud burst, bud set, flower opening, leaf morphology and height increment was examined within and between local and non-local provenances of Prunus spinosa in a provenance trial, located in Flanders (northern part of Belgium), during two consecutive years (shrubs were three and four years old) which contrasted strongly in spring temperatures. Five Flemish provenances were included together with three commercially available provenances originating from Wallonia (southern part of Belgium), Hungary and Spain. When comparing the two observational years, the Spanish provenance showed a plastic temporal response in bud burst, while the Hungarian provenance and to a lesser extent the Walloon provenance responded plastically in bud set. The Hungarian provenance flushed first in 2013 but was not the first to flush in 2014, whereas in 2014 flowers opened first. The rank order among the provenances in flushing was not maintained in flower opening although both phenophases occur congruently. Wide-leaved shrubs tended to flush and flower slightly earlier and to grow slightly quicker compared to narrow-leaved shrubs, possibly as a result of historical hybridisation processes. Height increment did not vary significantly between the Flemish and commercial provenances, except the Hungarian provenance, which showed a slightly retarded youth growth. The different responses between local and non-local provenances may indicate maladaptation of the latter. Natürliche Populationen von Gehölzarten sind an die lokalen Wachstumsbedingungen adaptiert. Nicht-lokale Herkünfte könnten einen Unterschied zwischen der lokalen Umwelt und den Standortsbedingungen in ihrer Ursprungsregion erfahren. Um den Einfluss der Auswahl der Herkünfte von Pflanzmaterial für (Wieder-)Aufforstungen und Landschaftsbegrünung zu untersuchen, erfassten wir die Variation der adaptiven Merkmale Aufspringen der Knospen, Knospenansatz, Öffnen der Blüten, Blattmorphologie und Höhenwachstum bei lokalen und auswärtigen Herkünften von Prunus spinosa. Wir nutzen eine Versuchsfläche in Flandern (nördliches Belgien) in zwei aufeinander folgenden Jahren, die sich stark hinsichtlich der Frühjahrstemperaturen unterschioeden (Alter der Sträucher: drei bzw. vier Jahre). Fünf flämische Herkünfte wurden untersucht sowie drei kommerziell erhältliche Herkünfte aus Wallonien (südliches Belgien), Ungarn und Spanien. Beim Vergleich der beiden Jahre zeigte die spanische Herkunft eine plastische zeitliche Reaktion beim Knospensprung, während die ungarische Herkunft und in geringerem Maße die wallonische Herkunft plastisch beim Knospenansatz reagierten. Die Ungarische Herkunft trieb 2013 als erste aus, war aber 2014 nicht die früheste Herkunft, während sie 2014 als erste die Blüten öffnete. Die Reihenfolge der Herkünfte beim Austreiben wurde nicht beim Öffnen der Blüten beibehalten. Breitblättrige Sträucher tendierten dazu, etwas früher auszutreiben, zu blühen und etwas schneller zu wachsen als schmalblättrige Sträucher, was möglicherweise auf historische Hybridisierungen zurückzuführen ist. Die Größenzunahme unterschied sich nicht signifikant zwischen den flämischen und den kommerziellen Herkünften. Nur die ungarische Herkunft zeigte ein leicht verzögertes Jugendwachstum. Die unterschiedlichen Reaktionen der lokalen und auswärtigen Herkünfte könnten eine Fehlanpassung der letztgenannten anzeigen. © 2015 Gesellschaft für Ökologie.


Vander Mijnsbrugge K.,Research Institute for Nature and Forest | Vander Mijnsbrugge K.,Agency for Nature and Forest | Beeckman H.,Royal Museum for Central Africa
Plant Systematics and Evolution | Year: 2012

Despite their genetic homogeneity, many taxonomic species are described as European dogroses (Rosa L. section Caninae (DC.) Ser.) with consistent morphological variability. Here we report a morphometric study of 27 hip and leaf characters of proximate dogrose populations that include Rosa agrestis, a member of the subsection Rubigineae, in Flanders. In principal components analysis one R. agrestis population in Kanne had intermediate morphology between R. canina and R. corymbifera, on the one hand, and three other R. agrestis populations, on the other, suggesting hybridogenic origin. Half-sib R. agrestis seedlings were grown under controlled conditions and their leaf characters were studied. A tendency toward deviating morphology in seedlings from the Kanne population, analogous to the mother plants in the field, and a correlation for specific leaf characters between mother plants and their corresponding seedlings reinforce a genetic basis for the observed divergence in the Kanne population. The assumed hybridogenic mother plants did not produce fewer seeds per hip than the others of the pure populations. In addition, for all sampled dogroses, which included six species, the diameter of the discus was correlated with the number of seeds per hip, whereas the diameter of the orifice was not correlated with this character. This implies that only the diameter of the orifice and not the diameter of the discus might be decisive for species identification among European dogroses. © 2012 Springer-Verlag.


Vander Mijnsbrugge K.,Research Institute for Nature and Forest | Vander Mijnsbrugge K.,Agency for Nature and Forest | Depypere L.,Ghent University | Chaerle P.,Ghent University | And 2 more authors.
Plant Ecology and Evolution | Year: 2013

Background and aims - Seed sourcing on a local scale is an emerging awareness among nature conservationists. Guidelines should be tuned for woody species in highly anthropogenic landscapes such as Flanders (Belgium). We investigated the genetic variation within and between eight autochthonous Flemish Prunus spinosa populations and assessed their potential as seed source for gene conservation and ecological restoration.Methods and key results - All sampled sites were old hedges or wooded banks.Using AFLP, the overall gene diversity (Ht) was estimated at 0.13, with a low average between population diversity (Hb = 0.02) and a comparatively high average within-population diversity (Hw = 0.11).The genetic differentiation was remarkably variable among populations (φST ranging from 0.07 to 0.43). There was no clear relationship between genetic and geographic distances, nor between genetic and morphometric characteristics. Only a small but signifcant correlation between endocarp and leaf morphological characters was observed. Conclusions - The variable genetic differentiation among populations points to different vegetation histories. Two populations, DEF and WES, were characterized by a dominant presence of sloe, high genetic differentiation from all other populations and low within-population diversities. No obvious morphometric variability of leaves could be related to these genetically deviating populations, however, WES showed a deviating endocarp morphology. Possibly, these two populationswere originally planted or supplemented using local and much related material whereas the others may have been planted with more diverse material. The relatively high within-population diversities and moderate, although variable, between-population differentiation of the other Flemish populations point to a considerable amount of gene exchange and can justify extensive seed sourcing for the production of autochthonous planting stock. These results stress the importance of a proper evaluation of genetic diversity for seed source selection and the need for regional feld-applicable guidelines. © 2013 National Botanic Garden of Belgium and Royal Botanical Society of Belgium.


Vander Mijnsbrugge K.,Research Institute for Nature and Forest | Vander Mijnsbrugge K.,Agency for Nature and Forest | Onkelinx T.,Research Institute for Nature and Forest | De Cuyper B.,Research Institute for Nature and Forest
Plant Systematics and Evolution | Year: 2015

To study the impact of provenance selection of planting stock in (re)forestation and landscape plantings, the variation in bud and flower phenology, height increment and shrub morphology was examined within and between the local and non-local provenances of Crataegus monogyna in a provenance trial. Seven Belgian provenances were included, five in Flanders and two in Wallonia, completed with three commercial provenances originating from Italy, Hungary and the United Kingdom. A completely randomized design (single tree plots) was adopted. Data were processed using mixed modelling techniques. South European provenances flushed up to 7 days earlier than the Flemish provenances, whereas the Walloon provenances flushed 4 days later. Compared to the Flemish provenances, Southern provenances and Walloon provenances flowered 4 days earlier and 2 days later respectively. Height increment and shrub morphology did not vary significantly between the Belgian and commercial provenances. Bud burst varied less than flowering among the Flemish and the Walloon provenances. This possibly indicates a higher selection pressure on bud burst than on flowering. The higher time lag between the different provenances for bud burst in comparison to flowering indicates a stronger plastic response for the latter. The results point out the importance of bud burst as an indicator of local adaptation to geo-climatologic components. Finally, it appeared that old hedges are likely to be good sources of locally adapted seed. © 2014, Springer-Verlag Wien.

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