2014

The influence of neighboring plants on plant reproduction in high stress environments

Category: Use of Space Technology to Maintain the Earth as an Oasis and Using Extreme Environments on the Earth to Understand the Potential for Life Elsewhere

Institution: Dartmouth College, USA

In stressful or extreme environments, the survival and reproduction of some plants may be facilitated by neighboring plants that reduce local environmental stress. For example, shrubs may abate damaging wind speeds on wind-scoured mountaintops or shade neighboring plants in hot deserts. Most research on facilitation has focused on how neighboring plants alter the local abiotic environment. However, neighboring plants may also alter the activity of other organisms that influence plant survival and reproduction, such as mutualists, herbivores, or parasites. Pollinators are important mutualists that been overlooked in studies on facilitation in stressful environments despite the fact that 88% of plant species depend on pollinators for reproduction. This research will answer the following question: How do neighboring plants alter plant reproduction in stressful environments, and what is the relative strength of abiotic vs. pollinator – mediated mechanisms?

This research was conducted above the Arctic Circle in Kangerlussuaq, West Greenland. Greenland, which has few plant and insect species, making it a tractable system to study species interactions. In addition, because the study area is directly adjacent to the Greenland Ice Sheet, it is a stressful environment in terms of strong winds (katabatic winds originate from the ice sheet), cold temperatures (average summer temperature of 7 °C), and, due to cold temperatures and little nutrient input, low soil development. The work focused on how Salix glauca (greyleaf willow), which is the dominant shrub in the study area, and other co-occurring plants affect the reproduction of Dryas integrifolia (Arctic avens, in the rose family). Neighboring plants, particularly Salix, are predicted to facilitate Dryas reproduction by blocking wind; increasing temperatures via lowering albedo; increasing soil nutrients via producing litter; and attracting pollinators by producing pollen- and nectar-rich flowers.

This research meets the Earth and Space Foundation’s objectives for using space to help maintain the earth as an oasis and using earth to understand other worlds and create a space-faring civilization. The Arctic is warming rapidly due to climate change, causing a notable increase in shrub growth. This research helps elucidate how this “shrubification” will alter plant reproduction, potentially leading to changes in plant communities and species interactions.  Using satellite imagery to quantify the current plant community was crucial for this aspect of the research. The high stress environment of this arctic study area will also provide insight into how plant communities organize in extreme environments and how this organization facilitates plant reproduction.

The Geology of the Drac Valley in the Champsaur region, Parc National des Écrins, French Alps.

Category: Use of Space Technology to Maintain the Earth as an Oasis

Institution: University of Cambridge

The main objective of the project is to investigate, and produce maps of, the geology of the Drac Valley in the French Alps.

The project focused  on the stratigraphic and structural aspects of the Drac Valley, located  in the Tertiary Alpine Foreland Basin (TAFB) of the external zone of the French Alps. The TAFB is thought to have formed as a flexural response to thrust loading of the European plate during a continental-continental collision. This means that we expect to find extensive folding and faulting of the rocks in the area.

Considerable use of GPS and satellite imagery was applied to make maps as accurate as possible. This technology enabled the project to accurately constrain the structures and faulting of the area so that  these deformation events can be put into context with the wider view of the continental collision that shaped this part of the planet. The project therefore gives us an opportunity to investigate some of the consequences of our tectonic plates system, which is unique to Earth in the Solar System.

The project will involved stratigraphic studies of the area, with the potential to create stratigraphic logs through Mesozoic and Cenozoic units. Through analysis of the stratigraphy, especially the Tertiary sediments,  inferences can be made about the environments in which the units were laid down.  This allowed for an investigation of the changing environment of this area as the continental collision was taking place, which can help further our understanding of our uniquely dynamic environment on the surface of the Earth.