La adaptación de la flora y fauna al cambio climático en un paisaje fragmentado y el Derecho europeo sobre la conservación de la naturaleza

Este trabajo analiza el papel de la Directiva Aves y la Directiva Hábitats de laUE con relación a los corredores ecológicos (o conectividad ecológica) y teniendo en cuentala fragmentación del paisaje y el cambio climático. Además de este análisis general, se centra en el caso de los Países Bajos, que resulta de especial interés

EU Regulation 1143/2014 and the Bern Convention:Allied forces in the war on invasive alien species

This article identifies and analyzes current and potential synergies between the new EU Regulation 1143/2014 on the prevention and management of the introduction and spread of invasive alien species on the one hand, and the Bern Convention on the Conservation of European Wildlife and Natural Habitats on the other. Besides focussing on the role the Convention could play in facilitating the Regulation’s effective implementation generally, the article explores the scope for extending some of the actions provided for in the Regulation beyond the EU to Europe at large, using the framework of the Bern Convention. The article identifies and recommends several courses of action that may be taken in either regard. Cooperation on IAS appears to open a promising new chapter in the dynamic interplay that has characterized the relations between the Bern Convention and EU biodiversity law in the past

On the photosynthetic responses of crops to intracanopy lighting with light emitting diodes

Key words: Cucumis sativus, intracanopy lighting, light-emitting diodes (LEDs), light distribution, light interception, light quality, photosynthesis, photosynthetic acclimation Assimilation lighting is a production factor of increasing importance in Dutch greenhouse horticulture. Assimilation lighting increases production levels, improves product quality and opens possibilities for year round production. As a drawback, this use of assimilation lighting increases energy inputs and CO2-emission. Intracanopy lighting (with LEDs) is a technique to enhance the light use efficiency by changing the position of (a part of ) the lamps from above to within the canopy of greenhouse grown crops. Intracanopy lighting (IL) firstly reduces reflection and transmission losses of the supplemental lighting on crop level. These losses are high in traditional top-lighting systems, hence IL yields a higher light absorption on crop level. Secondly, IL creates a more homogenous vertical light distribution which can result in higher light use efficiencies. The aim of present study was to obtain insights in photosynthetic acclimation in response to irradiance level and spectrum in the framework of the applicability of LEDs as light source for intracanopy lighting in indeterminate growing vegetable crops. Intracanopy lighting may vary in (1) position within the crop, in (2) irradiance level and in (3) spectrum. Leaves deeper in the canopy are older. If leaf age negatively affects the photosynthetic capacity (Amax), then potential positions of IL-lamps reduce. By growing tomato plants horizontally so that irradiance was similar for all leaves from 0-70 days old, it is concluded that during the normal life-span of tomato leaves in cultivation, irradiance and not ageing is the most important factor affecting Amax. In winter, natural irradiances are low so that new developing leaves acclimate to low irradiances. Later on in their life time these leaves could be exposed to higher irradiances owing to IL. The question arose if cucumber leaves which develop under low irradiance can acclimate to a moderate irradiance. Acclimation of photosynthesis occurred within 7 days but photosynthesis at moderate irradiance and Amax did not reach to that of leaves developed under moderate irradiance. This reveals the importance of photosynthetic acclimation during the leaf developmental phase for crop productivity in scenarios with realistic, moderate fluctuations in irradiance that leaves can be exposed to. By growing plants under seven different combinations of red and blue light, blue light is shown to have both a qualitative and a quantitative effect on leaf development. Only leaves developed under red light (0% blue) displayed a dysfunctional photosynthetic operation (“red light syndrome”), which was largely alleviated by only 7% blue. Quantitatively, leaf responses to an increasing blue light percentage resembled responses associated with an increase in irradiance. Leaves developed under red light exposed to a mixture of red and blue (RB) completely recovered within 4 days after exposure to RB-light but remained limited in other leaf parameters, showing limitations in plasticity due to constraints arising from the prior leaf development. Leaves developed under RB also revealed the “red light syndrome” within 7 days of red illumination. Lastly, the effects of intracanopy lighting with LEDs on the production and development of a cucumber crop was investigated in winter. In the IL-treatment, LEDs supplied 38% of the supplemental irradiance within the canopy; the remaining 62% was supplied as top lighting by High-Pressure Sodium (HPS) lamps. The control was 100% top lighting (HPS lamps). Intracanopy lighting resulted in a greater Amax for leaves at deeper canopy layers but did not increase total biomass or fruit production. This was partly due to a reduced light interception caused by extreme leaf curling, which counteracted the expected higher light absorption by the crop, and partly to a lower dry matter partitioning to the fruits, and thus a greater dry matter partitioning to the leaves compared to the control. The effect of these factors on fruit yield was quantified using a explanatory crop model. Model calculations revealed a large negative effect on the fruit yield due to the greater partitioning to the leaves, whereas the negative effect of leaf curling was small. The effect of a greater Amax at deeper canopy layers was slightly positive. The last however might have indirectly caused the greater partitioning to the leaves as the greater Amax was associated with a preserved leaf mass per area. </p

Prevention, Precaution, Logic and Law: The Relationship between the Precautionary Principle and the Preventative Principle in International Law and Associated Questions

The main purpose of this article is to promote clarification of the relationship between the precautionary principle and the prevent(at)ive principle in public international law. One of the questions addressed in this connection is whether the presence of uncertainty is a condition for the applicability of the precautionary principle. The article stresses and discusses the distinction between preventative and precautionary logic on the one hand and the corresponding legal principles on the other hand. It concludes, among other things, that in the international law of the environment the precautionary principle must be regarded as having absorbed the preventative principle or, alternatively, as being its most developed form. The widespread endorsement of the precautionary principle has thus made the continued existence of a separate preventative principle in international law superfluous

The vulnerability of neighbouring communities and their investment in protected area:A speculative analysis

Climate change will increasingly impact species and habitat composition of protected areas, even if precise impacts are difficult to predict, especially in smaller areas. This raises questions for management authorities, not only regarding the ecological integrity of protected areas but also regarding wildlife that ‘escape’ and cause damage. The protected area is traditionally the primary responsibility of the management authority, but the introduction of charismatic and potentially damage-causing wildlife touches on the overlapping and shared commercial interests of the tourism industry and the neighbouring rural communities. As climate change manifests, the complex relationship between these three stakeholders is likely to become strained by the increased frequency of damage caused by wildlife as they attempt to move out of or expand their home ranges beyond the boundaries of the protected area. It is concluded that a laissez-faire approach to climate change by conservation authorities or protected area managers is likely to be problematic – particularly with respect to relationships with neighbouring rural communities. A greater awareness of climate change impacts among all stakeholders is required, including conservation agencies, the tourism industry and neighbouring rural communities and managing escaped wildlife should become a joint responsibility which is founded on a contractual agreement between these stakeholders

Haalbaarheid van LED-tussenbelichting bij roos: praktijkonderzoek op Marjoland

Doelstelling van dit onderzoek is een mechanische aanpk van tussenbelichting bij roos, waarbij onderscheid werd gemaakt tussen groeilicht-, stuurlicht- en temperastuureffecten binnen een gewas

Bistable hysteresis and resistance switching in hydrogen gold junctions

Current-voltage characteristics of H2-Au molecular junctions exhibit intriguing steps around a characteristic voltage of 40 mV. Surprisingly, we find that a hysteresis is connected to these steps with a typical time scale > 10 ms. This time constant scales linearly with the power dissipated in the junction beyond an ofset power P_s = IV_s. We propose that the hysteresis is related to vibrational heating of both the molecule in the junction and a set of surrounding hydrogen molecules. Remarkably, we can engineer our junctions such that the hysteresis' characteristic time becomes >days. We demonstrate that reliable switchable devices can be built from such junctions.Comment: Submitted to Phys. Rev. Let

When is it acceptable to kill a strictly protected carnivore:Exploring the legal constraints on wildlife management within Europe's Bern Convention

As wolf populations expand across Europe, many countries face challenges in finding ways to address the concerns of some elements among the rural stakeholders who are being asked to share their landscapes with wolves for the first time in several generations. In these recovery landscapes, wolves are associated with a wide range of conflicts that include economic, psychological, perceptional, social, cultural and political dimensions. A recurring demand concerns the desire to introduce the use of carefully regulated lethal control of wolves, through either culling by state employees or hunting conducted by rural hunters. Introducing such measures can be very controversial, and many critics challenge their legality under the international wildlife conservation instruments that have nurtured wolf recovery. We evaluate this issue for the case of wolves in Norway, which are strictly protected under the Bern Convention. Drawing on the latest results of social science research, we present the multiple lines of argumentation that are often used to justify killing wolves and relate these to the criteria for exceptions that exist under the Bern Convention. We conclude that while the Convention provides apparent scope for allowing the killing of wolves as a means to address conflicts, this must be clearly justified and proportional to the conservation status of wolves so as to not endanger their recovery