Horsterwold - Veluwe - Maaswoud: een quick scan van robuuste ecologische verbindingen van het ambitieniveau 'edelhert'

De natuur in Nederland raakt steeds meer versnipperd. De gevolgen worden goed zichtbaar wanneer wordt gekeken naar de situatie van grote zoogdieren als het edelhert. Teruggedrongen achter rasters in een sub-optimaal habitat leven zij op twee plaatsen: de Veluwe en de Oostvaardersplassen. Het voorkomen van edelherten in andere, grootschalige natuurgebieden wordt van belang geacht voor de compleetheid van deze ecosystemen. Realisatie van de EHS biedt in dit opzicht onvoldoende kansen. Daarom zijn door het Rijk en de provincies een aantal zogenaamde robuuste verbindingen indicatief op kaart gezet. Doel daarbij kan zijn uitbreiding van het huidige leefgebied van het edelhert en het bieden van de mogelijkheid van migratie. Dit rapport is de weerslag van een ecologisch onderzoek naar mogelijke aanvullingen op de reeds verkende robuuste verbindingen voor het edelhert. Daartoe werden elf potentiële tracés verkend. Onderzocht is de mogelijkheid om de Veluwe te verbinden met het Horsterwold, de Utrechtse Heuvelrug en Duitsland via de Gelderse Poort. Tevens is onderzocht hoe vanuit dit laatste gebied de verbinding met het Maaswoud zou kunnen worden gerealiseerd. Ecologische en economische argumenten worden gepresenteerd om te helpen een keuze te bepalen tussen de mogelijke verbindingen

Impact of nationwide enhanced implementation of best practices in pancreatic cancer care (PACAP-1):a multicenter stepped-wedge cluster randomized controlled trial

Background: Pancreatic cancer has a very poor prognosis. Best practices for the use of chemotherapy, enzyme replacement therapy, and biliary drainage have been identified but their implementation in daily clinical practice is often suboptimal. We hypothesized that a nationwide program to enhance implementation of these best practices in pancreatic cancer care would improve survival and quality of life. Methods/design: PACAP-1 is a nationwide multicenter stepped-wedge cluster randomized controlled superiority trial. In a per-center stepwise and randomized manner, best practices in pancreatic cancer care regarding the use of (neo)adjuvant and palliative chemotherapy, pancreatic enzyme replacement therapy, and metal biliary stents are implemented in all 17 Dutch pancreatic centers and their regional referral networks during a 6-week initiation period. Per pancreatic center, one multidisciplinary team functions as reference for the other centers in the network. Key best practices were identified from the literature, 3 years of data from existing nationwide registries within the Dutch Pancreatic Cancer Project (PACAP), and national expert meetings. The best practices follow the Dutch guideline on pancreatic cancer and the current state of the literature, and can be executed within daily clinical practice. The implementation process includes monitoring, return visits, and provider feedback in combination with education and reminders. Patient outcomes and compliance are monitored within the PACAP registries. Primary outcome is 1-year overall survival (for all disease stages). Secondary outcomes include quality of life, 3- and 5-year overall survival, and guideline compliance. An improvement of 10% in 1-year overall survival is considered clinically relevant. A 25-month study duration was chosen, which provides 80% statistical power for a mortality reduction of 10.0% in the 17 pancreatic cancer centers, with a required sample size of 2142 patients, corresponding to a 6.6% mortality reduction and 4769 patients nationwide. Discussion: The PACAP-1 trial is designed to evaluate whether a nationwide program for enhanced implementation of best practices in pancreatic cancer care can improve 1-year overall survival and quality of life. Trial registration: ClinicalTrials.gov, NCT03513705. Trial opened for accrual on 22th May 2018

Impact of nationwide enhanced implementation of best practices in pancreatic cancer care (PACAP-1): A multicenter stepped-wedge cluster randomized controlled trial

Background: Pancreatic cancer has a very poor prognosis. Best practices for the use of chemotherapy, enzyme replacement therapy, and biliary drainage have been identified but their implementation in daily clinical practice is often suboptimal. We hypothesized that a nationwide program to enhance implementation of these best practices in pancreatic cancer care would improve survival and quality of life. Methods/design: PACAP-1 is a nationwide multicenter stepped-wedge cluster randomized controlled superiority trial. In a per-center stepwise and randomized manner, best practices in pancreatic cancer care regarding the use of (neo)adjuvant and palliative chemotherapy, pancreatic enzyme replacement therapy, and metal biliary stents are implemented in all 17 Dutch pancreatic centers and their regional referral networks during a 6-week initiation period. Per pancreatic center, one multidisciplinary team functions as reference for the other centers in the network. Key best practices were identified from the literature, 3 years of data from existing nationwide registries within the Dutch Pancreatic Cancer Project (PACAP), and national expert meetings. The best practices follow the Dutch guideline on pancreatic cancer and the current state of the literature, and can be executed within daily clinical practice. The implementation process includes monitoring, return visits, and provider feedback in combination with education and reminders. Patient outcomes and compliance are monitored within the PACAP registries. Primary outcome is 1-year overall survival (for all disease stages). Secondary outcomes include quality of life, 3- and 5-year overall survival, and guideline compliance. An improvement of 10% in 1-year overall survival is considered clinically relevant. A 25-month study duration was chosen, which provides 80% statistical power for a mortality reduction of 10.0% in the 17 pancreatic cancer centers, with a required sample size of 2142 patients, corresponding to a 6.6% mortality reduction and 4769 patients nationwide. Discussion: The PACAP-1 trial is designed to evaluate whether a nationwide program for enhanced implementation of best practices in pancreatic cancer care can improve 1-year overall survival and quality of life. Trial registration: ClinicalTrials.gov, NCT03513705. Trial opened for accrual on 22th May 2018

Managed water levels and the expansion of emergent vegetation along a lakeshore

Water-level fluctuations may be used to promote the expansion of emergent vegetation along lakeshores. The authors present the case of the lake Volkerak-Zoommeer in the Netherlands, a freshwater lake created in 1987 after the enclosure of an estuary. Using an experimental area in which the water level could be manipulated, it was shown that partial summer drawdown of the shoreline created suitable conditions for germination and growth of tall emergent species (in particular Phragmites australis). Plant survival and growth depended on subsequent water-level fluctuations and grazing by waterbirds. Based on the experiment and empincai data, a model was developed to predict the effects of the water-level regime on potential reed bed development. The model was applied for four hydrological scenarios that have been considered for the water-level management of the lakeWater-level fluctuations may be used to promote the expansion of emergent vegetation along lakeshores. We present the case of the lake Volkerak-Zoommeer in the Netherlands, a freshwater lake created in 1987 after the enclosure of an estuary. Using an experimental area in which the water level could be manipulated, it was shown that partial summer drawdown of the shoreline created suitable conditions for germination and growth of tall emergent species (in particular Phragmites australis). Plant survival and growth depended on subsequent water-level fluctuations and grazing by waterbirds. Based on the experiment and empirical data, a model was developed to predict the effects of the water-level regime on potential reed bed development. The model was applied for four hydrological scenarios that have been considered for the water-level management of the lake

Managed water levels and the expansion of emergent vegetation along a lakeshore

Water-level fluctuations may be used to promote the expansion of emergent vegetation along lakeshores. The authors present the case of the lake Volkerak-Zoommeer in the Netherlands, a freshwater lake created in 1987 after the enclosure of an estuary. Using an experimental area in which the water level could be manipulated, it was shown that partial summer drawdown of the shoreline created suitable conditions for germination and growth of tall emergent species (in particular Phragmites australis). Plant survival and growth depended on subsequent water-level fluctuations and grazing by waterbirds. Based on the experiment and empincai data, a model was developed to predict the effects of the water-level regime on potential reed bed development. The model was applied for four hydrological scenarios that have been considered for the water-level management of the lakeWater-level fluctuations may be used to promote the expansion of emergent vegetation along lakeshores. We present the case of the lake Volkerak-Zoommeer in the Netherlands, a freshwater lake created in 1987 after the enclosure of an estuary. Using an experimental area in which the water level could be manipulated, it was shown that partial summer drawdown of the shoreline created suitable conditions for germination and growth of tall emergent species (in particular Phragmites australis). Plant survival and growth depended on subsequent water-level fluctuations and grazing by waterbirds. Based on the experiment and empirical data, a model was developed to predict the effects of the water-level regime on potential reed bed development. The model was applied for four hydrological scenarios that have been considered for the water-level management of the lake

Effects of weather variability and geese on population dynamics of large herbivores creating opportunities for wood-pasture cycles : A modelling approach

(chapter 7 of PhD thesis)Coexistence of large herbivores and vegetation heterogeneity is a challenge for managers of relatively small and homogeneous nature reserves in fragmented landscapes. A modelling analysis was performed to study if observed variability in weather conditions would be of sufficient magnitude to maintain long-term coexistence of large herbivore species, and to provide windows of opportunity for the establishment of thorny shrubs as predicted by the wood-pasture hypothesis. The study was applied to the Oostvaardersplassen nature reserve in the Netherlands, which has a large herbivore assemblage of Heck cattle, Konik horse and red deer. Owing to the fact that a large number of geese frequent the nature reserve, the effects of these small herbivores were taken into account in the model analyses. The results showed that weather variability increases population fluctuations and that geese reduce large herbivore numbers. The results also indicated that coexistence of the three large herbivore species is possible irrespective of weather variability and geese. However, the chances for the coexistence of cattle with the other large herbivores are reduced when weather is highly variable and geese numbers are high. If the management of large nature reserves aims at natural processes with assemblages of self-regulating large herbivore populations, our results show that weather variability and the presence of small competing herbivores may be essential factors in highly productive environments for the wood-pasture cycle creating a more heterogeneous landscape

Modellen voor het beheer van hoefdierpopulaties in natuurterreinen

Onderzoek naar de interactie tussen grazers (edelhert, rund, paard) en vegetatie. Met behulp van het ruimtelijk begrazingsmodel WETSPACE voor moerasgebieden werd per ha nagegaan wat er gebeurt met de voorkomende vegetatie als er gegraasd wordt door hoefdieren en wordt de draagkracht berekend van het aantal grazers (edelhert, rund, paard). Gegevens in bijgaande figuur: Het totale hoefdiergewicht (adulten in juni) in de verschillende senario's (senario edelhert, rund, paard; senario edelhert, paard; senario rund; senario paard; senario edelhert