No simple relationship between above-ground tree growth and fine-litter production in tropical forests

An important deficiency of the tropical forest data set on above-ground net primary productivity (ANPP) is the paucity of studies where requisite components of forest productivity have been measured at the same location. Missing data on above-ground biomass increment (ABI, which refers to the incremental growth of trees) and fine-litter production (leaves, fruit, flowers, small twigs, but excluding coarse woody debris) is particularly problematic as these are the two major components of ANPP. The fragmentary nature of the data is reflected by the fact that only 13 of 39 (33%) plots reviewed by Clark et al. (2001) and 8 of 104 (8%) plots reviewed by Malhi et al. (2004) had data on both major components of productivity. In an attempt to retain the geographic coverage and replication of data in analyses, researchers have proposed ways to infer missing data. Typically ratios or (more recently) fitted relationships between ABI and litter production have been used for this purpose (Bray & Gorham 1964, Clark et al. 2001, Murphy 1975).

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Improving simulated Amazon forest biomass and productivity by including spatial variation in biophysical parameters

Biogeosciences ◽

10.5194/bg-10-2255-2013 ◽

2013 ◽

Vol 10 (4) ◽

pp. 2255-2272 ◽

Cited By ~ 40

Author(s):

A. D. A. Castanho ◽

M. T. Coe ◽

M. H. Costa ◽

Y. Malhi ◽

D. Galbraith ◽

...

Keyword(s):

Spatial Variability ◽

Spatial Heterogeneity ◽

Spatial Variation ◽

Primary Productivity ◽

Amazon Basin ◽

Net Primary Productivity ◽

Above Ground Biomass ◽

Biophysical Parameters ◽

Simulation Accuracy ◽

Forest Biome

Abstract. Dynamic vegetation models forced with spatially homogeneous biophysical parameters are capable of producing average productivity and biomass values for the Amazon basin forest biome that are close to the observed estimates, but these models are unable to reproduce observed spatial variability. Recent observational studies have shown substantial regional spatial variability of above-ground productivity and biomass across the Amazon basin, which is believed to be primarily driven by a combination of soil physical and chemical properties. In this study, spatial heterogeneity of vegetation properties is added to the Integrated Biosphere Simulator (IBIS) land surface model, and the simulated productivity and biomass of the Amazon basin are compared to observations from undisturbed forest. The maximum RuBiCo carboxylation capacity (Vcmax) and the woody biomass residence time (τw) were found to be the most important properties determining the modeled spatial variation of above-ground woody net primary productivity and biomass, respectively. Spatial heterogeneity of these properties may lead to simulated spatial variability of 1.8 times in the woody net primary productivity (NPPw) and 2.8 times in the woody above-ground biomass (AGBw). The coefficient of correlation between the modeled and observed woody productivity improved from 0.10 with homogeneous parameters to 0.73 with spatially heterogeneous parameters, while the coefficient of correlation between the simulated and observed woody above-ground biomass improved from 0.33 to 0.88. The results from our analyses with the IBIS dynamic vegetation model demonstrated that using single values for key ecological parameters in the tropical forest biome severely limits simulation accuracy. Clearer understanding of the biophysical mechanisms that drive the spatial variability of carbon allocation, τw and Vcmax is necessary to achieve further improvements to simulation accuracy.

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Reconstruction of above-ground biomass and net primary productivity of dominant tree species in Guizhou forests over past five decades based on tree-ring data

Acta Ecologica Sinica ◽

10.5846/stxb201903250558 ◽

2020 ◽

Vol 40 (10) ◽

Author(s):

刘立斌，许海洋，郭银明，梁辉，芦晓明，张慧，梁尔源，倪健 LIU Libin

Keyword(s):

Tree Ring ◽

Primary Productivity ◽

Tree Species ◽

Net Primary Productivity ◽

Above Ground Biomass ◽

Ground Biomass ◽

Tree Ring Data

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Accounting for spatial variation in vegetation properties improves simulations of Amazon forest biomass and productivity in a global vegetation model

Biogeosciences Discussions ◽

10.5194/bgd-9-11767-2012 ◽

2012 ◽

Vol 9 (8) ◽

pp. 11767-11813 ◽

Cited By ~ 1

Author(s):

A. D. de Almeida Castanho ◽

M. T. Coe ◽

M. Heil Costa ◽

Y. Malhi ◽

D. Galbraith ◽

...

Keyword(s):

Spatial Variability ◽

Spatial Heterogeneity ◽

Spatial Variation ◽

Primary Productivity ◽

Amazon Basin ◽

Net Primary Productivity ◽

Above Ground Biomass ◽

Vegetation Model ◽

Coefficient Of Correlation ◽

Forest Biome

Abstract. Dynamic vegetation models forced with spatially homogeneous biophysical parameters are capable of producing average productivity and biomass values for the Amazon basin forest biome that are close to the observed estimates, but are unable to reproduce the observed spatial variability. Recent observational studies have shown substantial regional spatial variability of above-ground productivity and biomass across the Amazon basin, which is believed to be primarily driven by soil physical and chemical properties. In this study, spatial heterogeneity of vegetation properties is added to the IBIS land surface model, and the simulated productivity and biomass of the Amazon basin are compared to observations from undisturbed forest. The maximum Rubisco carboxylation capacity (Vcmax) and the woody biomass residence time (τw) were found to be the most important properties determining the modeled spatial variation of above-ground woody net primary productivity and biomass, respectively. Spatial heterogeneity of these properties may lead to a spatial variability of 1.8 times in the simulated woody net primary productivity and 2.8 times in the woody above-ground biomass. The coefficient of correlation between the modeled and observed woody productivity improved from 0.10 with homogeneous parameters to 0.73 with spatially heterogeneous parameters, while the coefficient of correlation between the simulated and observed woody above-ground biomass improved from 0.33 to 0.88. The results from our analyses with the IBIS dynamic vegetation model demonstrate that using single values for key ecological parameters in the tropical forest biome severely limits simulation accuracy. We emphasize that our approach must be viewed as an important first step and that a clearer understanding of the biophysical mechanisms that drive the spatial variability of carbon allocation, τw and Vcmax are necessary.

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Net primary productivity following forest fire for Canadian ecoregions

Canadian Journal of Forest Research ◽

10.1139/x00-025 ◽

2000 ◽

Vol 30 (6) ◽

pp. 939-947 ◽

Cited By ~ 68

Author(s):

B D Amiro ◽

J M Chen ◽

Jinjun Liu

Keyword(s):

Primary Productivity ◽

Forest Fires ◽

Carbon Balance ◽

Net Primary Productivity ◽

Forest Carbon ◽

Data Set ◽

Area Index ◽

Boreal Plains ◽

Boreal Ecosystem ◽

Boreal Ecosystem Productivity Simulator

Recent modelling results indicate that forest fires and other disturbances determine the magnitude of the Canadian forest carbon balance. The regeneration of post-fire vegetation is key to the recovery of net primary productivity (NPP) following fire. We geographically co-registered pixels classed using the Boreal Ecosystem Productivity Simulator, a process-based model with AVHRR (advanced very-high resolution radiometer) satellite estimates of leaf-area index and land cover type, with polygons from a recent database of large Canadian fires. NPP development with time since fire was derived for the first 15 years following the disturbance in the boreal and taiga ecozones. About 7 × 106 ha were analysed for over 500 fires occurring between 1980 and 1994. NPP increases linearly through this period, at rates that depend on ecoregion. A longer data set for the Boreal Plains ecozone of Alberta shows that NPP levels off at about 20-30 years and remains constant for 60 years. The NPP trajectories can be used as spatial averages to support models of forest carbon balance and succession through the most fire-prone regions of Canada.

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Above-ground biomass and productivity in a rain forest of eastern South America

Journal of Tropical Ecology ◽

10.1017/s0266467408005075 ◽

2008 ◽

Vol 24 (4) ◽

pp. 355-366 ◽

Cited By ~ 106

Author(s):

Jérôme Chave ◽

Jean Olivier ◽

Frans Bongers ◽

Patrick Châtelet ◽

Pierre-Michel Forget ◽

...

Keyword(s):

Wood Density ◽

Primary Productivity ◽

Net Primary Productivity ◽

Basal Area ◽

Leaf Biomass ◽

Stem Density ◽

Above Ground Biomass ◽

Field Station ◽

Ground Biomass ◽

The Mean

AbstractThe dynamics of tropical forest woody plants was studied at the Nouragues Field Station, central French Guiana. Stem density, basal area, above-ground biomass and above-ground net primary productivity, including the contribution of litterfall, were estimated from two large permanent census plots of 12 and 10 ha, established on contrasting soil types, and censused twice, first in 1992–1994, then again in 2000–2002. Mean stem density was 512 stems ha−1 and basal area, 30 m2 ha−1. Stem mortality rate ranged between 1.51% and 2.06% y−1. In both plots, stem density decreased over the study period. Using a correlation between wood density and wood hardness directly measured by a Pilodyn wood tester, we found that the mean wood density was 0.63 g cm−3, 12% smaller than the mean of wood density estimated from the literature values for the species occurring in our plot. Above-ground biomass ranged from 356 to 398 Mg ha−1 (oven-dry mass), and it increased over the census period. Leaf biomass was 6.47 Mg ha−1. Our total estimate of aboveground net primary productivity was 8.81 MgC ha−1 y−1 (in carbon units), not accounting for loss to herbivory, branchfalls, or biogenic volatile organic compounds, which may altogether account for an additional 1 MgC ha−1 y−1. Coarse wood productivity (stem growth plus recruitment) contributed to 4.16 MgC ha−1 y−1. Litterfall contributed to 4.65 MgC ha−1 y−1 with 3.16 MgC ha−1 y−1 due to leaves, 1.10 MgC ha−1 y−1 to twigs, and 0.39 MgC ha−1 y−1 to fruits and flowers. The increase in above-ground biomass for both trees and lianas is consistent with the hypothesis of a shift in the functioning of Amazonian rain forests driven by environmental changes, although alternative hypotheses such as a recovery from past disturbances cannot be ruled out at our site, as suggested by the observed decrease in stem density.

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