Potential Arctic tundra vegetation shifts in response to changing temperature, precipitation and permafrost thaw

Over the past decades, vegetation and climate have changed significantly in the Arctic. Deciduous shrub cover is often assumed to expand in tundra landscapes, but more frequent abrupt permafrost thaw resulting in formation of thaw ponds could lead to vegetation shifts towards graminoid-dominated wetland. Which factors drive vegetation changes in the tundra ecosystem are still not sufficiently clear. In this study, the dynamic tundra vegetation model, NUCOM-tundra (NUtrient and COMpetition), was used to evaluate the consequences of climate change scenarios of warming and increasing precipitation for future tundra vegetation change. The model includes three plant functional types (moss, graminoids and shrubs), carbon and nitrogen cycling, water and permafrost dynamics and a simple thaw pond module. Climate scenario simulations were performed for 16 combinations of temperature and precipitation increases in five vegetation types representing a gradient from dry shrub-dominated to moist mixed and wet graminoid-dominated sites. Vegetation composition dynamics in currently mixed vegetation sites were dependent on both temperature and precipitation changes, with warming favouring shrub dominance and increased precipitation favouring graminoid abundance. Climate change simulations based on greenhouse gas emission scenarios in which temperature and precipitation increases were combined showed increases in biomass of both graminoids and shrubs, with graminoids increasing in abundance. The simulations suggest that shrub growth can be limited by very wet soil conditions and low nutrient supply, whereas graminoids have the advantage of being able to grow in a wide range of soil moisture conditions and have access to nutrients in deeper soil layers. Abrupt permafrost thaw initiating thaw pond formation led to complete domination of graminoids. However, due to increased drainage, shrubs could profit from such changes in adjacent areas. Both climate and thaw pond formation simulations suggest that a wetter tundra can be responsible for local shrub decline instead of shrub expansion.

Optimisation of the food dairy coop supply chain

In the European Union under the Common Agricultural Policy (CAP) milk production was restricted by milk quotas since 1984. However, due to recent changes in the Common Agricultural Policy (CAP), milk quotas will be abolished by 2015. Therefore, the European dairy sector will soon face an opportunity, for the first time in a generation, to expand. Numerous studies have shown that milk production in Ireland will increase significantly post quotas (Laepple and Hennessy (2010), Donnellan and Hennessy (2007) and Lips and Reider (2005)). The research in this thesis explored milk transport and dairy product processing in the Irish dairy processing sector in the context of milk quota removal and expansion by 2020. In this study a national milk transport model was developed for the Irish dairy industry, the model was used to examine different efficiency factors in milk transport and to estimate milk transport costs post milk quota abolition. Secondly, the impact of different milk supply profiles on milk transport costs was investigated using the milk transport model. Current processing capacity in Ireland was compared against future supply, it was concluded that additional milk processing capacity would not be sufficient to process the additional milk. Thirdly, the milk transport model was used to identify the least cost locations (based on transport costs) to process the additional milk supply in 2020. Finally, an optimisation model was developed to identify the optimum configuration for the Irish dairy processing sector in 2020 taking cognisance of increasing transport costs and decreasing processing costs.

Hidden land and changing landscape: Narratives about Mount Khangchendzonga among the Lepcha and the Lhopo

This article explores contemporary ‘hidden land’ narrative constructs of Máyel Lyáng and Beyul Dremojong in Sikkim, India, as conceived by the Lepcha and the Lhopo, two ‘scheduled tribes’. Lepcha and Lhopo narratives about these hidden lands in Mount Khangchendzonga inform us about their contemporary and historical, indigenous and Buddhist contexts and the interactions between these contexts. Lhopo perspectives on the hidden Beyul Dremojong echo classical Tibetan Buddhist ‘revealed treasure’ guidebooks and exist within the complex and reciprocal relationship between the Lhopo and the land they inhabit; development initiatives are understood to have caused illness and death in the Lhopo community of Tashiding, often referred to as the geographical ‘center’ of Beyul Dremojong. Contemporary Lepcha comprehensions of Máyel Lyáng, described in oral narratives within an ethnic community whose cosmology is intimately connected with Mount Khangchendzonga, today show some influence of Lhopo interpretations of Beyul Dremojong and the treasure texts; they also reflect Lepcha fears about cultural dispersion. Present-day narratives about both hidden lands reference notable political events in modern Sikkimese history (encounters with the British; the Chinese occupation of Tibet).