scholarly journals Siberian larch forests and the ion content of thaw lakes form a geochemically functional entity

2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Ulrike Herzschuh ◽  
Luidmila A. Pestryakova ◽  
Larissa A. Savelieva ◽  
Liv Heinecke ◽  
Thomas Böhmer ◽  
...  
Keyword(s):  
Siberian Larch ◽  
Ion Content ◽  
Functional Entity ◽  
Larch Forests ◽  
Thaw Lakes

scholarly journals Vegetation Indices Do Not Capture Forest Cover Variation in Upland Siberian Larch Forests

2018 ◽  
Vol 10 (11) ◽  
pp. 1686 ◽  
Author(s):  
Michael Loranty ◽  
Sergey Davydov ◽  
Heather Kropp ◽  
Heather Alexander ◽  
Michelle Mack ◽  
...  
Keyword(s):  
Carbon Storage ◽  
Vegetation Change ◽  
Vegetation Index ◽  
Forest Cover ◽  
Global Climate ◽  
Vegetation Indices ◽  
Temporal Trends ◽  
Siberian Larch ◽  
Field Observations ◽  
Larch Forests

Boreal forests are changing in response to climate, with potentially important feedbacks to regional and global climate through altered carbon cycle and albedo dynamics. These feedback processes will be affected by vegetation changes, and feedback strengths will largely rely on the spatial extent and timing of vegetation change. Satellite remote sensing is widely used to monitor vegetation dynamics, and vegetation indices (VIs) are frequently used to characterize spatial and temporal trends in vegetation productivity. In this study we combine field observations of larch forest cover across a 25 km2 upland landscape in northeastern Siberia with high-resolution satellite observations to determine how the Normalized Difference Vegetation Index (NDVI) and the Enhanced Vegetation Index (EVI) are related to forest cover. Across 46 forest stands ranging from 0% to 90% larch canopy cover, we find either no change, or declines in NDVI and EVI derived from PlanetScope CubeSat and Landsat data with increasing forest cover. In conjunction with field observations of NDVI, these results indicate that understory vegetation likely exerts a strong influence on vegetation indices in these ecosystems. This suggests that positive decadal trends in NDVI in Siberian larch forests may correspond primarily to increases in understory productivity, or even to declines in forest cover. Consequently, positive NDVI trends may be associated with declines in terrestrial carbon storage and increases in albedo, rather than increases in carbon storage and decreases in albedo that are commonly assumed. Moreover, it is also likely that important ecological changes such as large changes in forest density or variable forest regrowth after fire are not captured by long-term NDVI trends.

scholarly journals Assessing Forest Ecosystems across the Vertical Edge of the Mid-Latitude Ecotone Using the BioGeoChemistry Management Model (BGC-MAN)

Forests ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 523 ◽  
Author(s):  
Cholho Song ◽  
Stephan A. Pietsch ◽  
Moonil Kim ◽  
Sungeun Cha ◽  
Eunbeen Park ◽  
...  
Keyword(s):  
Transition Zone ◽  
Primary Productivity ◽  
Forest Ecosystems ◽  
Net Primary Productivity ◽  
Northeast Asia ◽  
Siberian Larch ◽  
Management Model ◽  
High Mountain ◽  
Specific Information ◽  
Larch Forests

The mid-latitude ecotone (MLE)—a transition zone between boreal and temperate forests, which includes the regions of Northeast Asia around 30°–60° N latitudes—delivers different ecosystem functions depending on different management activities. In this study, we assessed forest volume and net primary productivity changes in the MLE of Northeast Asia under different ecological characteristics, as well as various current management activities, using the BioGeoChemistry Management Model (BGC-MAN). We selected five pilot sites for pine (Scots pine and Korean red pine; Pinus sylvestris and P. densiflora), oak (Quercus spp.), and larch forests (Dahurian larch and Siberian larch; Larix gmelinii and L. sibirica), respectively, which covered the transition zone across the MLE from Lake Baikal, Russia to Kyushu, Japan, including Mongolia, Northeast China, and the Korean Peninsula. With site-specific information, soil characteristics, and management descriptions by forest species, we established their management characteristics as natural preserved forests, degraded forests, sandy and cold forest stands, and forests exposed to fires. We simulated forest volume (m3) and net primary productivity (Mg C ha−1) during 1960–2005 and compared the results with published literature. They were in the range of those specified in previous studies, with some site-levels under or over estimation, but unbiased estimates in their mean values for pine, oak, and larch forests. Annual rates of change in volume and net primary productivity differed by latitude, site conditions, and climatic characteristics. For larch forests, we identified a high mountain ecotype which warrants a separate model parameterization. We detected changes in forest ecosystems, explaining ecological transition in the Northeast Asian MLE. Under the transition, we need to resolve expected problems through appropriate forest management and social efforts.

scholarly journals Wildfires Dynamics in Siberian Larch Forests

Forests ◽  
2016 ◽  
Vol 7 (12) ◽  
pp. 125 ◽  
Author(s):  
Evgenii Ponomarev ◽  
Viacheslav Kharuk ◽  
Kenneth Ranson
Keyword(s):  
Siberian Larch ◽  
Larch Forests

Sensitivity of Siberian larch forests to climate change

2011 ◽  
Vol 17 (7) ◽  
pp. 2370-2384 ◽  
Author(s):  
JACQUELYN KREMPER SHUMAN ◽  
HERMAN HENRY SHUGART ◽  
THOMAS LIAM O'HALLORAN
Keyword(s):  
Climate Change ◽  
Siberian Larch ◽  
Larch Forests

scholarly journals Water, Energy, and Carbon Dioxide Circulation in Eastern Siberian Larch Forests: GAME, CREST and RIHN Results

2016 ◽  
Vol 29 (5) ◽  
pp. 294-312
Author(s):  
Takeshi OHTA ◽  
Tetsuya HIYAMA ◽  
Ayumi KOTANI ◽  
Takeshi YAMAZAKI ◽  
Trofim C. MAXIMOV
Keyword(s):  
Carbon Dioxide ◽  
Siberian Larch ◽  
Larch Forests

scholarly journals Evaluating the Differenced Normalized Burn Ratio for Assessing Fire Severity Using Sentinel-2 Imagery in Northeast Siberian Larch Forests

2021 ◽  
Vol 13 (12) ◽  
pp. 2311
Author(s):  
Clement J. F. Delcourt ◽  
Alisha Combee ◽  
Brian Izbicki ◽  
Michelle C. Mack ◽  
Trofim Maximov ◽  
...  
Keyword(s):  
Boreal Forests ◽  
Fire Severity ◽  
Siberian Larch ◽  
Fire Scars ◽  
Differenced Normalized Burn Ratio ◽  
Larch Forests ◽  
Normalized Burn Ratio ◽  
Burn Depth ◽  
Field Plots ◽  
Sentinel 2

Fire severity is a key fire regime characteristic with high ecological and carbon cycle relevance. Prior studies on boreal forest fires primarily focused on mapping severity in North American boreal forests. However, the dominant tree species and their impacts on fire regimes are different between North American and Siberian boreal forests. Here, we used Sentinel-2 satellite imagery to test the potential for using the most common spectral index for assessing fire severity, the differenced Normalized Burn Ratio (dNBR), over two fire scars and 37 field plots in Northeast Siberian larch-dominated (Larix cajanderi) forests. These field plots were sampled into two different forest types: (1) dense young stands and (2) open mature stands. For this evaluation, the dNBR was compared to field measurements of the Geometrically structured Composite Burn Index (GeoCBI) and burn depth. We found a linear relationship between dNBR and GeoCBI using data from all forest types (R2 = 0.42, p < 0.001). The dNBR performed better to predict GeoCBI in open mature larch plots (R2 = 0.56, p < 0.001). The GeoCBI provides a holistic field assessment of fire severity yet is dominated by the effect of fire on vegetation. No significant relationships were found between GeoCBI components (overall and substrate stratum) and burn depth within our fires (p > 0.05 in all cases). However, the dNBR showed some potential as a predictor for burn depth, especially in the dense larch forests (R2 = 0.63, p < 0.001). In line with previous studies in boreal North America, the dNBR correlated reasonably well with field data of aboveground fire severity and showed some skills as a predictor of burn depth. More research is needed to refine spaceborne fire severity assessments in the larch forests of Northeast Siberia, including assessments of additional fire scars and integration of dNBR with other geospatial proxies of fire severity.

Drivers of carbon emissions and active layer thickening from boreal wildfires in a continuous permafrost region of Northeast Siberia

2021 ◽  
Author(s):  
Clement J.F. Delcourt ◽  
Linar Akhmetzyanov ◽  
Brian Izbicki ◽  
Elena A. Kukavskaya ◽  
Michelle C. Mack ◽  
...  
Keyword(s):  
Active Layer ◽  
Climate Warming ◽  
Siberian Larch ◽  
Stand Age ◽  
Burned Area ◽  
Permafrost Region ◽  
Tree Species Composition ◽  
Continuous Permafrost ◽  
Larch Forests ◽  
Thaw Depth

&lt;p&gt;The circumpolar boreal biome is affected by increases in fire frequency and severity associated with climate warming. About 30% of the world&amp;#8217;s terrestrial carbon (C) is stored in the boreal region. Fires can produce large C emissions when substantial amounts of aboveground and belowground biomass and soil organic matter are combusted. Quantification and understanding of the drivers of C combustion is crucial to better assess the role of boreal fires in the global carbon cycle.&lt;/p&gt;&lt;p&gt;Despite the fact that the majority of boreal burned area occurs on the Eurasian continent, relatively few measurements of C combustion have been made in Eurasian boreal ecosystems. Here we synthetized data from 41 field sites collected during the summer of 2019 in Eastern Siberian larch forests. C combustion from surface and stand-replacing fires varied between 1.54 and 5.38 kg C/m&lt;sup&gt;2&lt;/sup&gt;. Belowground pools contributed in average to 73.9% of total C combustion. C combustion was higher in open larch-dominated forests (&lt;em&gt;Larix cajanderi&lt;/em&gt;) and open forests with a mixture of larch and pine (&lt;em&gt;Pinus sylvestris&lt;/em&gt;). High severity crown fires were observed in dense larch-dominated forests, yet C combustion was in average 23% lower than in the open stands. To our knowledge, this study is the first to quantify C combustion from wildfires in a continuous permafrost terrain in Northeast Siberia. We also investigated the effects of fire weather and pre-fire stand characteristics (e.g., stand age, drainage conditions, overstory tree species composition) on C combustion.&lt;/p&gt;&lt;p&gt;Because fires can also have a longer-term impact on permafrost environments through changes in surface energy balance and ground thermal regime, we also quantified active layer deepening in our study area. We measured thaw depth in 13 burned and 6 unburned sites one year after the fire. We explored the interactions between fire, vegetation, drainage conditions, and thaw depth. Our study shows that fire deepens the active layer, yet the magnitude of the effect is controlled by vegetation characteristics and topo-edaphic factors. Our findings provide insight to feedbacks between climate warming and boreal fires in permafrost-underlain larch forests in Siberia.&lt;/p&gt;

scholarly journals Strong cooling induced by stand-replacing fires through albedo in Siberian larch forests

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Dong Chen ◽  
Tatiana V. Loboda ◽  
Tao He ◽  
Yi Zhang ◽  
Shunlin Liang
Keyword(s):  
Siberian Larch ◽  
Larch Forests
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