Optimising state of environment monitoring at multiple scales using remotely sensed data

Proceedings of the 11th Australasian Remote Sensing and Photogrammetry Conference

Encounter success of free-ranging marine predator movements across a dynamic prey landscape

Movements of wide-ranging top predators can now be studied effectively using satellite and archival telemetry. However, the motivations underlying movements remain difficult to determine because trajectories are seldom related to key biological gradients, such as changing prey distributions. Here, we use a dynamic prey landscape of zooplankton biomass in the north-east Atlantic Ocean to examine active habitat selection in the plankton-feeding basking shark Cetorhinus maximus. The relative success of shark searches across this landscape was examined by comparing prey biomass encountered by sharks with encounters by random-walk simulations of ‘model’ sharks. Movements of transmitter-tagged sharks monitored for 964 days (16754km estimated minimum distance) were concentrated on the European continental shelf in areas characterized by high seasonal productivity and complex prey distributions. We show movements by adult and sub-adult sharks yielded consistently higher prey encounter rates than 90% of random-walk simulations. Behavioural patterns were consistent with basking sharks using search tactics structured across multiple scales to exploit the richest prey areas available in preferred habitats. Simple behavioural rules based on learned responses to previously encountered prey distributions may explain the high performances. This study highlights how dynamic prey landscapes enable active habitat selection in large predators to be investigated from a trophic perspective, an approach that may inform conservation by identifying critical habitat of vulnerable species.

Unplanned land clearing of Colombian rainforests: Spreading like disease?

Deforestation often occurs as temporal waves and in localized fronts termed 'deforestation hotspots' driven by economic pulses and population pressure. Of particular concern for conservation planning are 'biodiversity hotspots' where high concentrations of endemic species undergo rapid loss and fragmentation of habitat. We investigate the deforestation process in Caqueta, a biodiversity hotspot and major colonization front of the Colombian Amazon using multi-temporal satellite imagery of the periods 1989-1996-1999-2002. The probabilities of deforestation and regeneration were modeled against soil fertility, accessibility and neighborhood terms, using logistic regression analysis. Deforestation and regeneration patterns and rates were highly variable across the colonization front. The regional average annual deforestation rate was 2.6%, but varied locally between -1.8% (regeneration) and 5.3%, with maximum rates in landscapes with 40-60% forest cover and highest edge densities, showing an analogous pattern to the spread of disease. Soil fertility and forest and secondary vegetation neighbors showed positive and significant relationships with the probability of deforestation. For forest regeneration, soil fertility had a significant negative effect while the other parameters were marginally significant. The logistic regression models across all periods showed a high level of discrimination power for both deforestation and forest regeneration, with ROC values > 0.80. We document the effect of policies and institutional changes on the land clearing process, such as the failed peace process between government and guerillas in 1999-2002, which redirected the spread of deforestation and increased forest regeneration. The implications for conservation in biologically rich areas, such as Caqueta are discussed. (c) 2005 Elsevier B.V All rights reserved.

The MMPI-2 Gender-Masculine and Gender-Feminine scales: Gender roles as predictors of psychological health in clinical patients

Previous research measuring various biosocial factors such as age, sex, and marital status has found them to be essentially unrelated to measures of psychological health. Recent empirical studies have revealed that personality constructs may be more significant than demographic variables in the prediction of psychological well-being. The present study assessed the personality constructs of masculinity and femininity and hypothesized that the Gender-Masculine ( GM) scale of the MMPI-2 would be more effective than the Gender-Feminine (GF) scale in predicting psychological well-being. This hypothesis stems from previous research that has indicated the dominance of the masculinity model. It is suggested that previous research supporting androgyny as a primary indicator of well-being was influenced by the masculinity component of this gender orientation. One hundred and seventy-seven psychiatric patients from Australia (N = 107) and Singapore ( N 5 70) completed the MMPI-2. Hierarchical multiple regression revealed significantly stronger masculinity effects, with significance achieved on measures of ego strength and low self-esteem. No significant relationship between psychological well-being and the GF variable was found. Similarly, androgyny did not add any further variance to the model when masculinity was controlled for. Overall, the results are consistent with an interpretation that GM is a better correlate of psychological well-being as compared to the GF scale.