Identifying regional-scale self-organized patchiness in ecosystems using remote-sensing imagery

Category: Use of space technologies to maintain the Earth as an oasis 

Institution: Michigan Technological University, MI, USA

Changes in self-organized patterns of vegetation patchiness have been used to identify ecosystems at risk of a catastrophic shift to a new regime, most notably from a vegetated to a nonvegetated state. Once identified, these patterns could provide ecosystem managers with an early warning to try to avert these shifts. Vegetation patterns are developed and maintained by feedbacks between individual plants and local abiotic conditions, and have been identified in grasslands, shrublands and forests, using data from extensive on-the-ground field work and computer simulations. However, since these patterns occur at the landscape scale, they should be identifiable from remote sensing images, once the appropriate scale and metrics have been identified. More speculatively, since many living organisms create nonrandom occupation patterns in the process of niche construction (changing their local environment to better suit their requirements), if these patterns can be recognized remotely they could be used as an indicator for life on other planets. This project focuses on two ecosystems for which grazing and drought have been identified as drivers of self-organized patterns, resulting in changes from a vegetated to a denuded state: grazing lands in the Sahel; and grasslands in the Mediterranean region. In these ecosystems, changes from one pattern (e.g., striped) to another (e.g., spotted) signaling impending rapid vegetation loss occurs with greater distance from human settlement (as well as over time). Areas representing these different pattern stages within the same ecosystem were studied. LANDSAT (30 m resolution) and Quickbird imagery (0.6 m resolution), and ARCGIS software were used to identify: A) the scale at which these patterns are detected, relative to the scale at which the underlying processes occur, and B) the remote sensing metrics that detect these patterns with the greatest accuracy. Once the relevant landscape metrics have been tested on these two case studies, we will use this method on several areas of oak forests in the Zagros region of western Iran, to determine whether they can be used to identify a risk of vegetation loss due to the combination of overuse of the oak forests (harvesting and grazing), and impending climate change (through which the region is expected to get drier).

Searching for extraterrestrial biosignatures

Category: Astro and exobiology related fieldwork 

Institution: Open University, UK

Microbial metabolic activity is thought to play a crucial role in the deposition of  minerals, with the precipitation process occurring at a slow rate over geological time. Gaining a better understanding of the precipitation process and how it is affected by microbes is a fundamental step in the study of its contribution to study of  these mineral precipitates as biomarkers to search for life on Mars. As fossil hot spring deposits on Mars can be recognized by orbital imaging, the search for such microscopic physical biomarkers can help to provide the evidence of past or present life on other planets, such as Mars. Would the past and present day conditions have been favourable for precipitation? What would the precipitates be made of and what would they look like? In order to study bacterial precipitation and its influencing factors, fresh samples from modern precipitating platforms, such as found in Bermuda, have to be collected. This project, based in Bermuda, investigated the carbonate minerals produced by bacteria in the natural environment.