Synergism of optical and radar data for forest structure and biomass Sinergismo entre dados ópticos e de radar da estrutura da floresta e biomassa

Abstract The structure of forests, the three-dimensional arrangement of individual trees, has a profound effect on how ecosystems function and carbon cycle, water and nutrients. Repeated optical satellite observations of vegetation patterns in two-dimensions have made significant contributions to our understanding of the state and dynamics of the global biosphere. Recent advances in Remote Sensing technology allow us to view the biosphere in three-dimensions and provide us with refined measurements of horizontal as well as vertical structure of forests. This paper provides an overview of the recent advances in fusion of optical and radar imagery in assessing terrestrial ecosystem structure and aboveground biomass. In particular, the paper will focus on radar and LIDAR sensors from recent and planned spaceborne missions and provide theoretical and practical applications of the measurements. Finally, the relevance of these measurements for reducing the uncertainties of terrestrial carbon cycle and the response of ecosystems to future climate will be discussed in details. Resumo A estrutura de florestas, o arranjo tridimensional de arvores individuais, tem um efeito profundo sobre o funcionamento dos ecossistemas e do ciclo do carbono, agua e nutrientes. Repetidas observacoes de satelite optico de padroes de vegetacao em duas dimensoes trouxeram contribuicoes significativas para a nossa compreensao do estado e da dinâmica da biosfera global. Recentes avancos na tecnologia de Sensoriamento Remoto nos permitem ver a biosfera em tres dimensoes e nos fornecer medicoes apuradas da estrutura horizontal, bem como a vertical das florestas. Esse artigo fornece uma visao geral dos recentes avancos na fusao de imagens opticas e de radar para avaliar a estrutura do ecossistema terrestre e biomassa. Em particular, o trabalho concentra-se em sensores radar e LIDAR de recentes missoes espaciais planejadas e fornece aplicacoes teoricas e praticas das medicoes. Por fim, a relevância dessas medidas para reduzir as incertezas do ciclo de carbono terrestre e de resposta dos ecossistemas ao clima no futuro sera discutida em detalhes.

[1]  Heiko Balzter,et al.  Biomass estimation of Thetford forest from L-band SAR data: potential and limitations , 2003, IGARSS 2003. 2003 IEEE International Geoscience and Remote Sensing Symposium. Proceedings (IEEE Cat. No.03CH37477).

[2]  Mahta Moghaddam,et al.  Estimation of crown and stem water content and biomass of boreal forest using polarimetric SAR imagery , 2000, IEEE Trans. Geosci. Remote. Sens..

[3]  Konstantinos P. Papathanassiou,et al.  Polarimetric SAR interferometry , 1998, IEEE Trans. Geosci. Remote. Sens..

[4]  J. Blair,et al.  The Laser Vegetation Imaging Sensor: a medium-altitude, digitisation-only, airborne laser altimeter for mapping vegetation and topography , 1999 .

[5]  Karl J. Niklas,et al.  Botanical Scaling. (Book Reviews: Plant Allometry. The Scaling of Form and Process.) , 1994 .

[6]  John F. Weishampel,et al.  Multifractal analysis of canopy height measures in a longleaf pine savanna , 2000 .

[7]  Guoqing Sun,et al.  Boreal forest ecosystem characterization with SIR-C/XSAR , 1995, IEEE Trans. Geosci. Remote. Sens..

[8]  David J. Harding,et al.  Light transmittance in forest canopies determined using airborne laser altimetry and in-canopy quantum measurements , 2001 .

[9]  Lars M. H. Ulander,et al.  C-band repeat-pass interferometric SAR observations of the forest , 1997, IEEE Trans. Geosci. Remote. Sens..

[10]  W. Cohen,et al.  Surface lidar remote sensing of basal area and biomass in deciduous forests of eastern Maryland, USA , 1999 .

[11]  R. Dubayah,et al.  Sensitivity of large-footprint lidar to canopy structure and biomass in a neotropical rainforest , 2002 .

[12]  S. Hubbell,et al.  Spatial and temporal variation of biomass in a tropical forest: results from a large census plot in Panama , 2003 .

[13]  F. Siegert,et al.  ERS SAR backscatter: a potential real-time indicator of the proneness of modified rainforests to fire , 2001 .

[14]  Eric Rignot,et al.  Assessment of JERS-1 SAR for monitoring secondary vegetation in Amazonia: I. Spatial and temporal variability in backscatter across a chrono-sequence of secondary vegetation stands in Rondonia , 2002 .

[15]  Eric Rignot,et al.  Classification of boreal forest cover types using SAR images , 1997 .

[16]  R. Dubayah,et al.  Estimation of tropical forest structural characteristics using large-footprint lidar , 2002 .

[17]  Guoqing Sun,et al.  Validation of surface height from shuttle radar topography mission using shuttle laser altimeter , 2003 .

[18]  J. Chambers,et al.  Tree allometry and improved estimation of carbon stocks and balance in tropical forests , 2005, Oecologia.

[19]  R. Dubayah,et al.  Above-ground biomass estimation in closed canopy Neotropical forests using lidar remote sensing: factors affecting the generality of relationships , 2003 .

[20]  H. Shugart,et al.  Forest textural properties from simulated microwave backscatter: The influence of spatial resolution , 1994 .

[21]  Richard Condit,et al.  Error propagation and scaling for tropical forest biomass estimates. , 2004, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[22]  Yanhong Tang,et al.  Overestimated Biomass Carbon Pools of the Northern mid- and High Latitude Forests , 2006 .

[23]  R. Birdsey,et al.  National-Scale Biomass Estimators for United States Tree Species , 2003, Forest Science.

[24]  R. Dubayah,et al.  Lidar Remote Sensing for Forestry , 2000, Journal of Forestry.

[25]  F. Siegert,et al.  Increased damage from fires in logged forests during droughts caused by El Niño , 2001, Nature.

[26]  S. Saatchi,et al.  Measuring Woody Encroachment along a Forest–Savanna Boundary in Central Africa , 2009 .

[27]  Daniel B. Botkin,et al.  Biomass of the North American Boreal Forest A step toward accurate global measures , 1990 .

[28]  Kamal Sarabandi,et al.  Estimation of forest biophysical characteristics in Northern Michigan with SIR-C/X-SAR , 1995, IEEE Trans. Geosci. Remote. Sens..

[29]  Kamal Sarabandi,et al.  Simulation of interferometric SAR response for characterizing the scattering phase center statistics of forest canopies , 2000, IEEE Trans. Geosci. Remote. Sens..

[30]  Sassan Saatchi,et al.  Estimation of Forest Fuel Load From Radar Remote Sensing , 2007, IEEE Transactions on Geoscience and Remote Sensing.

[31]  Sandra Brown,et al.  BIOMASS OF TROPICAL FORESTS OF SOUTH AND SOUTHEAST ASIA , 1991 .

[32]  J. Bryan Blair,et al.  Beyond potential vegetation: Combining lidar data and a height-structured model for carbon studies , 2004 .

[33]  S. Goetz,et al.  Importance of biomass in the global carbon cycle , 2009 .