Events
Arturo Sánchez-Azofeifa
University of Alberta
Earth and Atmospheric Sciences Department
Edmonton, AB, Canada
Dr. Sanchez-Azofeifa’s activity involves the study of theoretical linkages between hyperspectral remote sensing and the spatio/temporal dynamics of Leaf Area Index (LAI), Primary Productivity (PP), and Photosynthetic Active Radiation (PAR) using wireless sensor networks deployed on tropical dry forests under difference successional stages. He has been awarded several international awards including the 2006 Aldo Leopold Leadership Fellowship. In 2008 was ranked in the top 1% of cited scientists in the area of ecology and the environment by Thompson Reuters.
Abstract
Micro-meteorological drivers of phenological clues on Tropical Dry and Wet Forests
My main interests in on the development and implementation of wireless sensor network (WSN), tools and algorithms that can be used to better understand linkages between phenological phenomena, and their direct observations via remote sensing. As par this initiatives my work deals with the following components of environmental monitoring:
a) Sensor development, testing and deployment.
b) Field evaluation of sensor performance, and their spatial deployment
c) Integration of WSN derived information at different scales to evaluate phenological clues on tropical dry and rainforests environments.
d) Validation of remote sensing derived products at different spatial scales from WSN derived information
e) Conceptualization, development and implementation of cyber-infrastructure applications for fast data analysis and query of environmental data.
My work is conducted in selected sites across the Americas, specifically in Mexico, Costa Rica, Panama, Brazil and Argentina using a system designed by my research group denominated Wireless Optical Phenology Stations (WOPS). The WOPS system is a combination of cameras, WSN deployed at different heights in the canopy, and a optical wireless system that provide insights into micro-meteorological drivers controlling phenological responses (e.g. water vapor deficits (VPDs), soil moisture and temperature, and the fraction of the Photosynthetically Active Radiation (PAR) absorved by vegetation. This WOPS system is complemented with a set of portable spectrometers that provide key information on the spectro-temporal variability of vegetation reflectance.
My main interests in terms of environmental research are aimed to understanding linkages between phenology and micro-climatology, specifically along the following the following research questions:
a) Do all tropical dry forests phenological responses have the same environmental controls? If not, which is more dominant as a function of given site/latitude?
b) What is the role between micro-climates and phenology of forests under different levels of succession? Does phenological expressions, controlled by micro-climate conditions occur at the same time or there is a time lag on the emergency of leaves in tropical dry forests?
c) What are the main micro-meteorological variables that control the phenological expression (leafing, fruit production, and flower production) of specific tropical rainforest species (e.g. Tabebuia guayacan) that can be monitored using high resolution remote sensing?
d) How WOPS can be used to better understand carbon and water fluxes (measured via eddy correlation towers) in tropical dry forests environments.
e) In a Brazilian context: how micro-meteorological conditions behave on sharp Cerrado-Dry Forest transitions?
f) How micro-meteorological variables such as temperature, relative humidity behave on tropical dry forests edges under different levels of succession?
It is fundamentally clear that, as today many of these questions require a significant amount of technology development. These technologies are not only associated to the development of sensors, and their circuit boards but also the necessary cyber-infrastructure that can provide quick access to data and its derived information. One specific case is the development of digital camera systems that can be used to measure phenology as function vegetation greenness in tropical environments. The development of this kind of system is constrained not only by the lack of field tested instrumentation, but also by the lack of standardized computer software that can be used for real or near-time data processing that can be linked to WOPS. As today, systems designed for temperate environments are not designed to properly work in areas of high precipitation, temperature and relative humidity. Further, current software is not designed for near- or realtime image processing with most data analysis been done at posteriori, limiting therefore its applicability for environmental decision making. The fact that many of these camera systems cannot be linked to wireless sensor networks for integrated decision making (e.g. sampling intervals), and satellite uplinks are also emerging limitations. Systems such as those currently been designed by Hoskin Scientific and MicroStream, as well as cyberinfrastructure initiatves such as Geochronos (http://geochronos.org) are providing futuristic solutions.