Carbon exchange in an Amazon forest: from hours to years

被引：23

作者：

Hayek, Matthew N. ^{[1
]}

Longo, Marcos ^{[2
]}

Wu, Jin ^{[3
]}

Smith, Marielle N. ^{[4
]}

Restrepo-Coupe, Natalia ^{[5
]}

Tapajos, Raphael ^{[6
]}

da Silva, Rodrigo ^{[6
]}

Fitzjarrald, David R. ^{[7
]}

Camargo, Plinio B. ^{[8
]}

Hutyra, Lucy R. ^{[9
]}

Alves, Luciana F. ^{[10
]}

Daube, Bruce ^{[11
]}

Munger, J. William ^{[11
]}

Wiedemann, Kenia T. ^{[11
]}

Saleska, Scott R. ^{[12
]}

Wofsy, Steven C. ^{[11
]}

机构：

[1] Harvard Law Sch, Cambridge, MA 02138 USA

[2] CALTECH, Jet Prop Lab, NASA, Pasadena, CA USA

[3] Brookhaven Natl Lab, Biol Environm & Climate Sci Dept, Upton, NY 11973 USA

[4] Michigan State Univ, Dept Forestry, E Lansing, MI 48824 USA

[5] Univ Technol Sydney, Plant Funct Biol & Climate Change Cluster, Sydney, NSW, Australia

[6] Univ Fed Oeste Para, Santarem, PA, Brazil

[7] SUNY Albany, Albany, NY 12222 USA

[8] Univ Sao Paulo, Ctr Energia Nucl Agr, Piracicaba, SP, Brazil

[9] Boston Univ, Dept Earth & Environm, Boston, MA 02215 USA

[10] Univ Calif Los Angeles, Inst Environm & Sustainabil, Ctr Trop Res, Los Angeles, CA USA

[11] Harvard Univ, Fac Arts & Sci, Cambridge, MA 02138 USA

[12] Univ Arizona, Dept Ecol & Evolutionary Biol, Tucson, AZ USA

来源：

BIOGEOSCIENCES | 2018年 / 15卷 / 15期

基金：

美国国家科学基金会;

关键词：

NET PRIMARY PRODUCTION; LEAF-AREA; LONG-TERM; PHOTOSYNTHETIC SEASONALITY; VEGETATION DYNAMICS; ATMOSPHERIC CO2; DROUGHT; CLIMATE; FLUXES; VARIABILITY;

D O I：

10.5194/bg-15-4833-2018

中图分类号：

Q14 [生态学（生物生态学）];

学科分类号：

071012 ; 0713 ;

摘要：

In Amazon forests, the relative contributions of climate, phenology, and disturbance to net ecosystem exchange of carbon (NEE) are not well understood. To partition influences across various timescales, we use a statistical model to represent eddy-covariance-derived NEE in an evergreen eastern Amazon forest as a constant response to changing meteorology and phenology throughout a decade. Our best fit model represented hourly NEE variations as changes due to sunlight, while seasonal variations arose from phenology influencing photosynthesis and from rainfall influencing ecosystem respiration, where phenology was asynchronous with dry-season onset. We compared annual model residuals with biometric forest surveys to estimate impacts of drought disturbance. We found that our simple model represented hourly and monthly variations in NEE well (R-2 = 0.81 and 0.59, respectively). Modeled phenology explained 1% of hourly and 26% of monthly variations in observed NEE, whereas the remaining modeled variability was due to changes in meteorology. We did not find evidence to support the common assumption that the forest phenology was seasonally light-or water-triggered. Our model simulated annual NEE well, with the exception of 2002, the first year of our data record, which contained 1.2 MgCha(-1) of residual net emissions, because photosynthesis was anomalously low. Because a severe drought occurred in 1998, we hypothesized that this drought caused a persistent, multi-year depression of photosynthesis. Our results suggest drought can have lasting impacts on photosynthesis, possibly via partial damage to still-living trees.

引用

页码：4833 / 4848

页数：16