Richard P. Armitage

Identification of the spectral characteristics of British semi-natural upland vegetation using direct ordination: a case study from Dartmoor, UK

The direct ordination technique Canonical Correspondence Analysis (CCA) is applied to the examination of the relationships between the floristic composition of semi-natural vegetation and its spectral reflectance. Paired measurements of floristic and spectral characteristics, the latter being measured using a portable field spectrometer, were collected at ground level for a range of upland semi-natural vegetation within two study sites on Dartmoor, south-west England. The spectral data were converted to simulate a Compact Airborne Spectrographic Imager (CASI) bandset. Both floristic and spectral data sets were then jointly ordinated using CCA. A sequence of individual species changes along the first ordination axis was identified that showed a strong correspondence with variation in the simulated CASI wavebands covering the 736 nm to 870 nm wavelengths. A significant relationship between first axis CCA scores for quadrats and their estimated total percentage vegetation cover was also identified. Although UK National Vegetation Classification (NVC) categories corresponded to a general sequence of plant community types along the first CCA axis, with the possible exception of the U20 Pteridium aquilinum-dominated community, it proved impossible to demonstrate any close link between any specific plant community type and a distinct set of spectral characteristics because of the continuum nature of the vegetation. The second axis of the CCA showed no interpretable relationship with variation in floristic/spectral data and this was confirmed further by use of Detrended Canonical Correspondence Analysis (DCCA). Possibilities for further research into floristic/spectral data using CCA/DCCA are discussed.

Testing the Application of Terrestrial Laser Scanning to Measure Forest Canopy Gap Fraction

Terrestrial laser scanners (TLS) have the potential to revolutionise measurement of the three-dimensional structure of vegetation canopies for applications in ecology, hydrology and climate change. This potential has been the subject of recent research that has attempted to measure forest biophysical variables from TLS data, and make comparisons with two-dimensional data from hemispherical photography. This research presents a systematic comparison between forest canopy gap fraction estimates derived from TLS measurements and hemispherical photography. The TLS datasets used in the research were obtained between April 2008 and March 2009 at Delamere Forest, Cheshire, UK. The analysis of canopy gap fraction estimates derived from TLS data highlighted the repeatability and consistency of the measurements in comparison with those from coincident hemispherical photographs. The comparison also showed that estimates computed considering only the number of hits and misses registered in the TLS datasets were consistently lower than those estimated from hemispherical photographs. To examine this difference, the potential information available in the intensity values recorded by TLS was investigated and a new method developed to estimate canopy gap fraction proposed. The new approach produced gap fractions closer to those estimated from hemispherical photography, but the research also highlighted the limitations of single return TLS data for this application.

Probability of cloud-free observation conditions across Great Britain estimated using MODIS cloud mask

Cloud cover is a major constraint on applications using optical remote sensing, particularly in temperate regions such as Great Britain (GB). This research explores the potential of the Moderate Resolution Imaging Spectroradiometer (MODIS) cloud mask product to calculate cloud probability across GB. MODIS 1 km cloud mask data for 2005 were downloaded and processed to map cloud-free probabilities. The results indicate an average yearly cloud-free probability of 21.3%, with maximum and minimum monthly mean probabilities of 33.3% and 12.9% in November and March, respectively. Temporal and spatial variations in cloud-free frequencies are apparent. Northern and western regions are generally cloudier than those in the south. The results of this research indicate that cloud probabilities can be identified at a relatively high spatial resolution.

Social-ecological innovation: adaptive responses to urban environmental conditions

Novel approaches to natural resource management, particularly those which promote stakeholder participation, have been put forward as fundamental ingredients for establishing resilient, polycentric forms of environmental governance. This is nowhere more pertinent than in the case of the complex adaptive systems associated with urban areas. Decentralisation of urban green space management has been posited as an element thereof which, according to resilience thinking, should contribute to the adaptive capacity of cities and the ecosystem services upon which they rely. Implicit in this move towards increased adaptive capacity is the ability to manage through innovation. Although the importance of innovation towards system adaptability has been acknowledged, little work has thus far been carried out which demonstrates that innovative use of urban green space represents a form of adaptive response to environmental conditions. The current paper reports on research which maps examples of organised social-ecological innovation (OSEI) in an urban study area and evaluates them as adaptive responses to local environmental conditions which may contribute to system resilience. The results present OSEI as a coherent body of responses to local social and environmental deprivation, exhibiting diversity and adaptability according to individual contexts. The study therefore provides evidence for the importance of local stakeholder-led innovation as in the building of adaptive capacity in urban social-ecological systems.

Towards a collaborative urban planning environment

Various urban planning stakeholders may have conflicting views on development plans and proposals. In order to achieve a shared understanding and facilitate decision making among stakeholders, this paper presents a collaborative urban planning workspace. This workspace is comprised of advanced display systems and optical tracking technologies. A distributed system framework is designed to integrate user interaction, rendering, services and data management capabilities. The system prototype has been implemented and some test scenarios have been examined with user groups.