Comparing Forest Measurements from Tree Rings and a Space-Based Index of Vegetation Activity in Siberia

Different methods have been developed for measuring carbon stocks and fluxes in the northern high latitudes, ranging from intensively measured small plots to space-based methods that use reflectance data to drive production efficiency models. The field of dendroecology has used samples of tree growth from radial increments to quantify long-term variability in ecosystem productivity, but these have very limited spatial domains. Since the cambium material in tree cores is itself a product of photosynthesis in the canopy, it would be ideal to link these two approaches. We examine the associations between the normalized differenced vegetationindex (NDVI) and tree growth using 19 pairs of tree-ring widths (TRW) and maximum latewood density (MXD) across much ofSiberia. We find consistent correlations between NDVI and both measures of tree growth and no systematic difference between MXD and TRW. At the regional level we note strong correspondence between the first principal component of tree growth and NDVI for MXD and TRW in a temperature-limited bioregion, indicating that canopy reflectance and cambial production are broadly linked. Using a network of 21 TRW chronologies from south of Lake Baikal, we find a similarly strong regional correspondence with NDVI in a markedly drier region. We show that tree growth is dominated by variation at decadal and multidecadal time periods, which the satellite record is incapable of recording given its relatively short record

Effect of contrasting water supply on the diameter growth of Norway spruce and aspen in mixed stands: a case study from the southern Russian taiga

Stem radial growth of Norway spruce (Picea abies (L.) Karst.), aspen (Populus tremula L.), birch (Betula alba L.), alder (Alnus incana (L.) Moench) and mountain ash (Sorbus aucuparia L.) was measured in an unmanaged mixed uneven-aged tree stand in the southern taiga of European Russia by band dendrometers during the growing seasons of 2000–2001. In addition woody cores were taken from sample spruce and aspen trees using increment borers for dendrochronological analysis. Analysis of the tree rings was made for period from 1999 to 2002, the period while daily meteorological data were available. Spruce and aspen represented 40 and 44% of the entire stand basal area, respectively. However, basal area has grown over 60% of the total in spruce and less than 15% in aspen for each year during the period of 1999–2002. These results indicate the transformation processes of secondary aspen-spruce stands of the Southern European Taiga into a mixed spruce-aspen-birch stands. The most intensive radial growth of the spruce trees was observed in 2000 with high over-watering conditions in summer, whereas the highest radial growth in aspen was observed during the extremely dry growing season of 2002. The basal area growth for entire forest stand ranged from 5.3 m2 ha–1 in 1999 to 11.4 m2 ha–1 in 2000. Annual increments of radial growth measured by dendrometers and by microscopic evaluation of woody cores were quite similar in spruce. In contrast, this comparison was poor for aspen trees because zero growth in some of aspen trees (measured by dendrometers) was occurred.Effets d’une alimentation en eau variée sur la croissance en diamètre de l’épicéa et du tremble dans des peuplements mélangés étudiés dans le sud de la taïga russe. La croissance radiale saisonnière de l’épicéa (Picea abies (L.) Karst.), du tremble (Populus tremula L.), du bouleau (Betula alba L.), de l’aulne (Alnus incana (L.) Moench) et du sorbier (Sorbus aucuparia L.) a été mesurée, dans une forêt mixte non gérée dominée par l’épicéa et le tremble, et située dans la taïga du sud en Russie d’Europe. Les mesures ont été effectuées à l’aide de dendromètres à ruban pendant les saisons 2000–2001 en parallèle avec les données météorologiques. En plus des carottes de bois ont été prélevées sur tous les épicéas et trembles mesurés pour faire une analyse dendrochronologique. L’épicéa et le tremble représentaient 40 et 44 % de la surface terrière du peuplement. Néanmoins, annuellement dans la période 1999–2002, la croissance de la surface terrière de l’épicéa représentait plus de 60 % de la croissance totale de la surface terrière contre moins de 15 % pour le tremble. Ces résultats révèlent la transformation de la forêt secondaire de trembles en forêt mixte à dominance d’épicéa. La croissance la plus forte de l’épicéa été observée pendant la saison 2000, caractérisée par une surabondance de l’eau dans le sol pendant l’été, tandis que la croissance maximale du tremble a été observée pendant la saison extrêmement sèche du 2002. La croissance totale de la surface terrière du peuplement variait de 5.3 m2 ha–1 en 1999 jusqu’à 11.4 m2 ha–1 en 2000. La croissance annuelle radiale mesurée par les dendromètres et par la mesure des accroissements annuels sur les carottes de sondage était similaire chez l’épicéa. En contraste chez le tremble, cette concordance était faible à cause de l’absence de croissance radiale d’une partie des trembles mesurés par les dendromètres

Regionally, the first principal component of a cluster of Siberian tree-ring data correlated positively (green colors) with mean July NDVI for both TRW ((A) and (B)) and MXD ((C) and (D))

<p><strong>Figure 3.</strong> Regionally, the first principal component of a cluster of Siberian tree-ring data correlated positively (green colors) with mean July NDVI for both TRW ((A) and (B)) and MXD ((C) and (D)). Significant correlations (<em>p</em> < 0.05) are shown in the top row while the whole correlation field is shown in the bottom row. Individual sites (seven total chronologies at four sites) are shown as small blue dots while the centroid of those sites is shown as a bigger blue square.</p> <p><strong>Abstract</strong></p> <p>Different methods have been developed for measuring carbon stocks and fluxes in the northern high latitudes, ranging from intensively measured small plots to space-based methods that use reflectance data to drive production efficiency models. The field of dendroecology has used samples of tree growth from radial increments to quantify long-term variability in ecosystem productivity, but these have very limited spatial domains. Since the cambium material in tree cores is itself a product of photosynthesis in the canopy, it would be ideal to link these two approaches. We examine the associations between the normalized differenced vegetation index (NDVI) and tree growth using 19 pairs of tree-ring widths (TRW) and maximum latewood density (MXD) across much of Siberia. We find consistent correlations between NDVI and both measures of tree growth and no systematic difference between MXD and TRW. At the regional level we note strong correspondence between the first principal component of tree growth and NDVI for MXD and TRW in a temperature-limited bioregion, indicating that canopy reflectance and cambial production are broadly linked. Using a network of 21 TRW chronologies from south of Lake Baikal, we find a similarly strong regional correspondence with NDVI in a markedly drier region. We show that tree growth is dominated by variation at decadal and multidecadal time periods, which the satellite record is incapable of recording given its relatively short record.</p

Nineteen paired sets of tree-ring widths and maximum latewood density spanning 100° of longitude and 16° latitude and five species were used across Siberia

<p><strong>Figure 1.</strong> Nineteen paired sets of tree-ring widths and maximum latewood density spanning 100° of longitude and 16° latitude and five species were used across Siberia. Cross-reference to table <a href="http://iopscience.iop.org/1748-9326/8/3/035034/article#erl477471t1" target="_blank">1</a>.</p> <p><strong>Abstract</strong></p> <p>Different methods have been developed for measuring carbon stocks and fluxes in the northern high latitudes, ranging from intensively measured small plots to space-based methods that use reflectance data to drive production efficiency models. The field of dendroecology has used samples of tree growth from radial increments to quantify long-term variability in ecosystem productivity, but these have very limited spatial domains. Since the cambium material in tree cores is itself a product of photosynthesis in the canopy, it would be ideal to link these two approaches. We examine the associations between the normalized differenced vegetation index (NDVI) and tree growth using 19 pairs of tree-ring widths (TRW) and maximum latewood density (MXD) across much of Siberia. We find consistent correlations between NDVI and both measures of tree growth and no systematic difference between MXD and TRW. At the regional level we note strong correspondence between the first principal component of tree growth and NDVI for MXD and TRW in a temperature-limited bioregion, indicating that canopy reflectance and cambial production are broadly linked. Using a network of 21 TRW chronologies from south of Lake Baikal, we find a similarly strong regional correspondence with NDVI in a markedly drier region. We show that tree growth is dominated by variation at decadal and multidecadal time periods, which the satellite record is incapable of recording given its relatively short record.</p

Correlations were calculated between NDVI and tree growth (<em>r</em>_tree|NDVI) fortnightly over the spring and summer for the four-pixel neighborhood around each site

<p><strong>Figure 2.</strong> Correlations were calculated between NDVI and tree growth (<em>r</em>_tree|NDVI) fortnightly over the spring and summer for the four-pixel neighborhood around each site. Some sites showed significant correlations at 95% confidence (dashed horizontal lines) in summer months (especially July) although there was no clear systematic difference between ring widths (TRW) and density (MXD).</p> <p><strong>Abstract</strong></p> <p>Different methods have been developed for measuring carbon stocks and fluxes in the northern high latitudes, ranging from intensively measured small plots to space-based methods that use reflectance data to drive production efficiency models. The field of dendroecology has used samples of tree growth from radial increments to quantify long-term variability in ecosystem productivity, but these have very limited spatial domains. Since the cambium material in tree cores is itself a product of photosynthesis in the canopy, it would be ideal to link these two approaches. We examine the associations between the normalized differenced vegetation index (NDVI) and tree growth using 19 pairs of tree-ring widths (TRW) and maximum latewood density (MXD) across much of Siberia. We find consistent correlations between NDVI and both measures of tree growth and no systematic difference between MXD and TRW. At the regional level we note strong correspondence between the first principal component of tree growth and NDVI for MXD and TRW in a temperature-limited bioregion, indicating that canopy reflectance and cambial production are broadly linked. Using a network of 21 TRW chronologies from south of Lake Baikal, we find a similarly strong regional correspondence with NDVI in a markedly drier region. We show that tree growth is dominated by variation at decadal and multidecadal time periods, which the satellite record is incapable of recording given its relatively short record.</p

Continuous wavelet transformations of the first principal component of the central Siberian MXD data (top) and TRW (bottom) show significant power at decadal and multidecadal periods over the period 1880–1998

<p><strong>Figure 4.</strong> Continuous wavelet transformations of the first principal component of the central Siberian MXD data (top) and TRW (bottom) show significant power at decadal and multidecadal periods over the period 1880–1998. For instance, the red colors indicate persistent variability in tree growth at a period of decades (from about 16 to 32 years) in both TRW and MXD while the cooler colors indicate little in the way of power at higher frequencies (e.g., interannual). Color scale is by 10% quantiles.</p> <p><strong>Abstract</strong></p> <p>Different methods have been developed for measuring carbon stocks and fluxes in the northern high latitudes, ranging from intensively measured small plots to space-based methods that use reflectance data to drive production efficiency models. The field of dendroecology has used samples of tree growth from radial increments to quantify long-term variability in ecosystem productivity, but these have very limited spatial domains. Since the cambium material in tree cores is itself a product of photosynthesis in the canopy, it would be ideal to link these two approaches. We examine the associations between the normalized differenced vegetation index (NDVI) and tree growth using 19 pairs of tree-ring widths (TRW) and maximum latewood density (MXD) across much of Siberia. We find consistent correlations between NDVI and both measures of tree growth and no systematic difference between MXD and TRW. At the regional level we note strong correspondence between the first principal component of tree growth and NDVI for MXD and TRW in a temperature-limited bioregion, indicating that canopy reflectance and cambial production are broadly linked. Using a network of 21 TRW chronologies from south of Lake Baikal, we find a similarly strong regional correspondence with NDVI in a markedly drier region. We show that tree growth is dominated by variation at decadal and multidecadal time periods, which the satellite record is incapable of recording given its relatively short record.</p

The first principal component from a collection of 21 TRW chronologies from <em>Pinus sylvestris</em> in the Buryatia region show similar positive correlation (green colors) with July NDVI (compare to figure 3)

<p><strong>Figure 5.</strong> The first principal component from a collection of 21 TRW chronologies from <em>Pinus sylvestris</em> in the Buryatia region show similar positive correlation (green colors) with July NDVI (compare to figure <a href="http://iopscience.iop.org/1748-9326/8/3/035034/article#erl477471fig3" target="_blank">3</a>). Significant correlations (<em>p</em> < 0.05) are shown in the top panel while the whole correlation field is shown in the bottom panel. Individual sites are shown as small blue dots while the centroid of those sites is shown as a bigger blue square.</p> <p><strong>Abstract</strong></p> <p>Different methods have been developed for measuring carbon stocks and fluxes in the northern high latitudes, ranging from intensively measured small plots to space-based methods that use reflectance data to drive production efficiency models. The field of dendroecology has used samples of tree growth from radial increments to quantify long-term variability in ecosystem productivity, but these have very limited spatial domains. Since the cambium material in tree cores is itself a product of photosynthesis in the canopy, it would be ideal to link these two approaches. We examine the associations between the normalized differenced vegetation index (NDVI) and tree growth using 19 pairs of tree-ring widths (TRW) and maximum latewood density (MXD) across much of Siberia. We find consistent correlations between NDVI and both measures of tree growth and no systematic difference between MXD and TRW. At the regional level we note strong correspondence between the first principal component of tree growth and NDVI for MXD and TRW in a temperature-limited bioregion, indicating that canopy reflectance and cambial production are broadly linked. Using a network of 21 TRW chronologies from south of Lake Baikal, we find a similarly strong regional correspondence with NDVI in a markedly drier region. We show that tree growth is dominated by variation at decadal and multidecadal time periods, which the satellite record is incapable of recording given its relatively short record.</p

Descriptive statistics for the nineteen pairs of TRW and MXD tree-ring data from Siberia

<p><b>Table 1.</b>  Descriptive statistics for the nineteen pairs of TRW and MXD tree-ring data from Siberia. Species codes: PISY (<em>Pinus sylvestris</em>), LAGM (<em>Larix gmelinii</em>), PIOB (<em>Picea obovata</em>), LASI (Larix sibirica), LACA (<em>Larix cajanderi</em>). <em>n</em>: number of cross-dated tree-ring series at each site. <em>r</em>_TRW|MXD: correlation between the TRW and MXD chronologies over the years in the period column. \bar {r}: mean interseries correlation of pre-whitened series. EPS: expressed population signal. : first-order autocorrelation. </p> <p><strong>Abstract</strong></p> <p>Different methods have been developed for measuring carbon stocks and fluxes in the northern high latitudes, ranging from intensively measured small plots to space-based methods that use reflectance data to drive production efficiency models. The field of dendroecology has used samples of tree growth from radial increments to quantify long-term variability in ecosystem productivity, but these have very limited spatial domains. Since the cambium material in tree cores is itself a product of photosynthesis in the canopy, it would be ideal to link these two approaches. We examine the associations between the normalized differenced vegetation index (NDVI) and tree growth using 19 pairs of tree-ring widths (TRW) and maximum latewood density (MXD) across much of Siberia. We find consistent correlations between NDVI and both measures of tree growth and no systematic difference between MXD and TRW. At the regional level we note strong correspondence between the first principal component of tree growth and NDVI for MXD and TRW in a temperature-limited bioregion, indicating that canopy reflectance and cambial production are broadly linked. Using a network of 21 TRW chronologies from south of Lake Baikal, we find a similarly strong regional correspondence with NDVI in a markedly drier region. We show that tree growth is dominated by variation at decadal and multidecadal time periods, which the satellite record is incapable of recording given its relatively short record.</p