Response of photosynthesis of different plant functional types to environmental changes along Northeast China Transect

G. Jiang; Haiping Tang; M. Yu; Ming Dong; Xinshi Zhang

doi:10.1007/s004680050211

Towards spatial assessment of carbon sequestration in peatlands: spectroscopy based estimation of fractional cover of three plant functional types

Biogeosciences ◽

10.5194/bg-6-275-2009 ◽

2009 ◽

Vol 6 (2) ◽

pp. 275-284 ◽

Cited By ~ 12

Author(s):

G. Schaepman-Strub ◽

J. Limpens ◽

M. Menken ◽

H. M. Bartholomeus ◽

M. E. Schaepman

Keyword(s):

Environmental Changes ◽

Spatial Scales ◽

Vascular Plant ◽

C Sequestration ◽

Plant Functional Types ◽

Vegetation Composition ◽

Fractional Cover ◽

Functional Types ◽

C Stocks ◽

Historical Times

Abstract. Peatlands accumulated large carbon (C) stocks as peat in historical times. Currently however, many peatlands are on the verge of becoming sources with their C sequestration function becoming sensitive to environmental changes such as increases in temperature, decreasing water table and enhanced nitrogen deposition. Long term changes in vegetation composition are both, a consequence and indicator of future changes in C sequestration. Spatial continuous accurate assessment of the vegetation composition is a current challenge in keeping a close watch on peatland vegetation changes. In this study we quantified the fractional cover of three major plant functional types (PFTs; Sphagnum mosses, graminoids, and ericoid shrubs) in peatlands, using field spectroscopy reflectance measurements (400–2400 nm) on 25 plots differing in PFT cover. The data was validated using point intercept methodology on the same plots. Our results showed that the detection of open Sphagnum versus Sphagnumcovered by vascular plants (shrubs and graminoids) is feasible with an R2 of 0.81. On the other hand, the partitioning of the vascular plant fraction into shrubs and graminoids revealed lower correlations of R2 of 0.54 and 0.57, respectively. This study was based on a dataset where the reflectance of all main PFTs and their pure components within the peatland was measured at local spatial scales. Spectrally measured species or plant community abundances can further be used to bridge scaling gaps up to canopy scale, ultimately allowing upscaling of the C balance of peatlands to the ecosystem level.

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SPATIAL VARIABILITY OF PLANT FUNCTIONAL TYPES OF TREES ALONG NORTHEAST CHINA TRANSECT

Applied Ecology and Environmental Research ◽

10.15666/aeer/0302_039049 ◽

2005 ◽

Vol 3 (2) ◽

pp. 39-49 ◽

Cited By ~ 3

Author(s):

X. Chen

Keyword(s):

Spatial Variability ◽

Northeast China ◽

Plant Functional Types ◽

Functional Types

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Responses of Sap Flux Densities of Different Plant Functional Types to Environmental Variables Are Similar in Both Dry and Wet Seasons in a Subtropical Mixed Forest

Forests ◽

10.3390/f12081007 ◽

2021 ◽

Vol 12 (8) ◽

pp. 1007

Author(s):

Kechao Huang ◽

Quan Wang ◽

Dennis Otieno

Keyword(s):

Flux Density ◽

Water Use ◽

Environmental Variables ◽

Environmental Changes ◽

Mixed Forest ◽

Plant Functional Types ◽

Photon Flux ◽

Sap Flux ◽

Sap Flux Density ◽

Functional Types

Subtropical mixed forest ecosystems are experiencing dramatic changes in precipitation and different plant functional types growing here are expected to respond differently. This study aims to unravel the water use patterns of different plant functional types and their responses to environmental changes in a typical subtropical mixed forest in southern China. Diurnal and seasonal sap flux densities of evergreen broad-leaved trees (EBL), deciduous broad-leaved trees (DBL), and conifers (CON), as well as environmental variables, were recorded simultaneously from May 2016 to March 2019. The results showed that the sap flux density of EBL was significantly higher than those of CON and DBL in all seasons, irrespective of dry or wet seasons. Path analysis revealed that seasonal differences in sap flux density were mainly due to variations in photosynthetic photon flux density (PPFD). At saturating PPFD, changes in sap flux density during the day were in response to vapor pressure deficit (VPD). Regression analyses showed that sap flux density increased logarithmically with PPFD, irrespective of functional type. The hysteresis loops of sap flux density and VPD were different among different plant functional types in wet and dry seasons. Our results demonstrated converging response patterns to environmental variables among the three plant functional types considered in this study. Our findings contribute to a better understanding of the water use strategies of different plant functional types in subtropical mixed forests.

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Towards spatial assessment of carbon sequestration in peatlands: spectroscopy based estimation of fractional cover of three plant functional types

Biogeosciences Discussions ◽

10.5194/bgd-5-1293-2008 ◽

2008 ◽

Vol 5 (2) ◽

pp. 1293-1317 ◽

Cited By ~ 5

Author(s):

G. Schaepman-Strub ◽

J. Limpens ◽

M. Menken ◽

H. M. Bartholomeus ◽

M. E. Schaepman

Keyword(s):

Carbon Sequestration ◽

Environmental Changes ◽

Spatial Scales ◽

Vascular Plant ◽

Plant Functional Types ◽

Vegetation Composition ◽

Fractional Cover ◽

Functional Types ◽

Ecosystem Level ◽

Historical Times

Abstract. Peatlands accumulated large carbon stocks as peat in historical times. Currently however, many peatlands are on the verge of becoming sources with their carbon sequestration function becoming sensitive to environmental changes such as increases in temperature, decreasing water table and enhanced nitrogen deposition. Long term changes in vegetation composition are both, a consequence and indicator of future changes in carbon sequestration. Spatial continuous accurate assessment of the vegetation composition is a current challenge in keeping a close watch on peatland vegetation changes. In this study we quantified the fractional cover of three major plant functional types (Sphagnum mosses, graminoids, and shrubs) in peatlands, using field spectroscopy reflectance measurements (400–2400 nm) on 25 plots differing in plant functional type cover. The data was validated using point intercept methodology on the same plots. Our results showed that the detection of open Sphagnum versus Sphagnum covered by vascular plants (shrubs and graminoids) is feasible with an R2 of 0.81. On the other hand, the partitioning of the vascular plant fraction into shrubs and graminoids revealed lower correlations of R2 of 0.54 and 0.57, respectively. This study was based on a dataset where the reflectance of all main plant functional types and their pure components within the peatland was measured at local spatial scales. Spectrally measured species or plant community abundances can further be used to bridge scaling gaps up to canopy scale, ultimately allowing upscaling of the C balance of peatlands to the ecosystem level.

Download Full-text