首页> 外文期刊>Nature >Amazon forests maintain consistent canopy structure and greenness during the dry season
【24h】

Amazon forests maintain consistent canopy structure and greenness during the dry season

机译:亚马逊森林在干旱季节保持一致的冠层结构和绿色

获取原文
获取原文并翻译 | 示例
           

摘要

最近来自亚马逊的遥感数据显示,旱季植被会变绿,这说明森林生产力的主要限制因素是光而不是水。现在,Douglas Morton及同事对该证据重新进行了分析,发现"变绿"事实上是观察方法在光学上产生的一个假象,是由卫星观察的相对方位角在六月份的夏至和九月份的秋分之间的变化造成的。纠正这一偏差会将"变绿"现象消除,从而为证明亚马逊森林植物生产力的主要驱动因素是水分供应而非光的其他研究进一步提供了支持。%The seasonality of sunlight and rainfall regulates net primary production in tropical forests. Previous studies have suggested that light is more limiting than water for tropical forest productivity, consistent with greening of Amazon forests during the dry season in satellite data. We evaluated four potential mechanisms for the seasonal green-up phenomenon, including increases in leaf area or leaf reflectance, using a sophisticated radiative transfer model and independent satellite observations from lidar and optical sensors. Here we show that the apparent green up of Amazon forests in optical remote sensing data resulted from seasonal changes in near-infrared reflectance, an artefact of variations in sun-sensor geometry. Correcting this bidirectional reflectance effect eliminated seasonal changes in surface reflectance, consistent with independent lidar observations and model simulations with unchanging canopy properties. The stability of Amazon forest structure and reflectance over seasonal timescales challenges the paradigm of light-limited net primary production in Amazon forests and enhanced forest growth during drought conditions. Correcting optical remote sensing data for artefacts of sun-sensor geometry is essential to isolate the response of global vegetation to seasonal and interannual climate variability.
机译:最近来自亚马逊的遥感数据显示,旱季植被会变绿,这说明森林生产力的主要限制因素是光而不是水。现在,Douglas Morton及同事对该证据重新进行了分析,发现"变绿"事实上是观察方法在光学上产生的一个假象,是由卫星观察的相对方位角在六月份的夏至和九月份的秋分之间的变化造成的。纠正这一偏差会将"变绿"现象消除,从而为证明亚马逊森林植物生产力的主要驱动因素是水分供应而非光的其他研究进一步提供了支持。%The seasonality of sunlight and rainfall regulates net primary production in tropical forests. Previous studies have suggested that light is more limiting than water for tropical forest productivity, consistent with greening of Amazon forests during the dry season in satellite data. We evaluated four potential mechanisms for the seasonal green-up phenomenon, including increases in leaf area or leaf reflectance, using a sophisticated radiative transfer model and independent satellite observations from lidar and optical sensors. Here we show that the apparent green up of Amazon forests in optical remote sensing data resulted from seasonal changes in near-infrared reflectance, an artefact of variations in sun-sensor geometry. Correcting this bidirectional reflectance effect eliminated seasonal changes in surface reflectance, consistent with independent lidar observations and model simulations with unchanging canopy properties. The stability of Amazon forest structure and reflectance over seasonal timescales challenges the paradigm of light-limited net primary production in Amazon forests and enhanced forest growth during drought conditions. Correcting optical remote sensing data for artefacts of sun-sensor geometry is essential to isolate the response of global vegetation to seasonal and interannual climate variability.

著录项

  • 来源
    《Nature》 |2014年第7487期|221-224121|共5页
  • 作者单位

    NASA Goddard Space Flight Center, Green belt, Maryland 20771, USA;

    University of Maryland, College Park, Department of Geographical Sciences, College Park, Maryland 20742, USA,Global Land Cover Facility, College Park, Maryland 20740, USA;

    NASA Goddard Space Flight Center, Green belt, Maryland 20771, USA,Sigma Space Corporation, Lantham, Maryland 20706, USA;

    NASA Goddard Space Flight Center, Green belt, Maryland 20771, USA,University of Maryland, College Park, Department of Geographical Sciences, College Park, Maryland 20742, USA,Swan sea University, Department of Geography, Singleton Park, Swansea SA2 8PP, UK;

    Earth System Research Center, University of New Hampshire, Durham, New Hampshire 03824, USA;

    NASA Goddard Space Flight Center, Green belt, Maryland 20771, USA;

    NASA Goddard Space Flight Center, Green belt, Maryland 20771, USA;

    NASA Goddard Space Flight Center, Green belt, Maryland 20771, USA;

    Swan sea University, Department of Geography, Singleton Park, Swansea SA2 8PP, UK;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);美国《生物学医学文摘》(MEDLINE);美国《化学文摘》(CA);
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号