Roberta E. Martin

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a Institut de Physique du Globe de Paris & Université Paris Diderot — Paris 7 (UMR 7154), Géophysique spatiale et planétaire, Case 89, 4 place Jussieu, 75252 Paris Cedex 05, France b Laboratoire Ecologie, Systématique et Evolution (UMR 8079), Université Paris-Sud, 91405 Orsay Cedex, France c Department of Global Ecology, Carnegie Institution of Washington,(More)
Mapping biological diversity is a high priority for conservation research, management and policy development, but few studies have provided diversity data at high spatial resolution from remote sensing. We used airborne imaging spectroscopy to map woody vascular plant species richness in lowland tropical forest ecosystems in Hawai’i. Hyperspectral(More)
• Canopy chemistry and spectroscopy offer insight into community assembly and ecosystem processes in high-diversity tropical forests, but phylogenetic and environmental factors controlling chemical traits underpinning spectral signatures remain poorly understood. • We measured 21 leaf chemical traits and spectroscopic signatures of 594 canopy individuals on(More)
Leaf chemical and spectral properties of 162 canopy species were measured at 11 tropical forest sites along a 6024 mm precipitation/yr and 8.7 degrees C climate gradient in Queensland, Australia. We found that variations in foliar nitrogen, phosphorus, chlorophyll a and b, and carotenoid concentrations, as well as specific leaf area (SLA), were expressed(More)
Biological invasions contribute to global environmental change, but the dynamics and consequences of most invasions are difficult to assess at regional scales. We deployed an airborne remote sensing system that mapped the location and impacts of five highly invasive plant species across 221,875 ha of Hawaiian ecosystems, identifying four distinct ways that(More)
A broad regional understanding of tropical forest leaf photosynthesis has long been a goal for tropical forest ecologists, but it has remained elusive due to difficult canopy access and high species diversity. Here we develop an empirical model to predict sunlit, light-saturated, tropical leaf photosynthesis using leaf and simulated canopy spectra. To(More)
BACKGROUND High fidelity carbon mapping has the potential to greatly advance national resource management and to encourage international action toward climate change mitigation. However, carbon inventories based on field plots alone cannot capture the heterogeneity of carbon stocks, and thus remote sensing-assisted approaches are critically important to(More)
We compiled a time series of Earth Observing-1 Hyperion satellite observations with field measurements to compare the structural, biochemical, and physiological characteristics of an invasive nitrogen-fixing tree Myrica faya and native Metrosideros polymorpha in montane rainforests in Hawai’i. Satellite-based canopy water measurements closely tracked(More)
Sources of variation among the chemical and spectral properties of tropical forest canopies are poorly understood, yet chemical traits reveal potential ecosystem and phylogenetic controls, and spectral linkages to chemical traits are needed for remote sensing of functional and biological diversity. We analyzed 21 leaf traits in 395 fully sunlit canopies,(More)
Canopy gaps express the time-integrated effects of tree failure and mortality as well as regrowth and succession in tropical forests. Quantifying the size and spatial distribution of canopy gaps is requisite to modeling forest functional processes ranging from carbon fluxes to species interactions and biological diversity. Using high-resolution airborne(More)