A 6 year longitudinal study of post-fire woody carbon dynamics in California’s forests

2016 ◽  
Vol 46 (5) ◽  
pp. 610-620 ◽  
Author(s):  
Bianca N.I. Eskelson ◽  
Vicente J. Monleon ◽  
Jeremy S. Fried
Keyword(s):  
Forest Fires ◽  
Forest Type ◽  
Fire Severity ◽  
National Forest Inventory ◽  
Repeated Measurements ◽  
Carbon Pools ◽  
Dead Trees ◽  
Wide Range ◽  
Standing Trees ◽  
Standing Dead

We examined the dynamics of aboveground forest woody carbon pools — live trees, standing dead trees, and down wood — during the first 6 years following wildfire across a wide range of conditions, which are characteristic of California forest fires. From repeated measurements of the same plots, we estimated change in woody carbon pools as a function of crown fire severity as indicated by a post-fire index, years since fire, pre-fire woody carbon, forest type group (hardwood vs. softwood), elevation, and climate attributes. Our analysis relied on 130 U.S. national forest inventory plots measured before and 1 year after fire, with one additional remeasurement within 6 years after fire. There was no evidence of net change in total wood carbon, defined for this study as the wood in standing trees larger than 12.7 cm diameter at breast height and down wood larger than 7.6 cm in diameter, over the post-fire period in any of the three severity classes. Stands that burned at low severity exhibited considerable shifts from live to standing dead and down wood pools. In stands that burned at moderate severity, live wood decreased significantly whereas no net change was detected in standing dead or down wood. High severity fire burning resulted in movement from standing dead to down wood pools. Our results suggest that the carbon trajectories for stand-replacing fires may not be appropriate for the majority of California’s forest area that burned at low to moderate severities.

scholarly journals The relationship between organic matter stocks in coarse woody debris and the stand phytomass in middle taiga pine forests on the European North-East Russia

2017 ◽  
Author(s):  
А.Ф. Осипов ◽  
И.Н. Кутявин
Keyword(s):  
Organic Matter ◽  
Forest Type ◽  
Woody Debris ◽  
Pine Forests ◽  
Stand Age ◽  
North East ◽  
European North ◽  
Dead Trees ◽  
Standing Dead ◽  
Standing Dead Trees

Приведены результаты исследований структуры и запасов крупных древес- ных остатков (КДО) в среднетаежных сосняках европейского Северо-Востока России, различающихся условиями произрастания и возрастом. К КДО относили сухостойные деревья, валеж и пни диаметром более 6 см. Определены запасы древесины и масса органического вещества в отдельных компонентах (сухостой, валеж, пни) КДО, которые зависят от стадии развития насаждения. Так, в перестойном сосняке черничном наблюдаются более высокие концентрации запасов древесины и органического вещества в гниющей древесине, тогда как в средне- возрастных насаждениях сосняков черничных и чернично-сфагновых более низ- кие. Во всех исследованных насаждениях отмечаются сухостойные деревья. Валеж, пни и сломанные на разной высоте деревья присутствуют в восьми насаждениях. Эти элементы КДО отсутствуют в средневозрастных сосновых древостоях черничного и чернично-сфагнового типа. Выявлено, что в валежнике преобладают деревья, древесина которых находится на начальных стадиях деструкции. По литературным данным представлены результаты исследований запа- сов органического вещества и их распределения по фракциям древостоя. Рассчи- тано соотношение между запасами растущих деревьев и КДО, которое варьирует в широких пределах в зависимости от возраста древостоев. Для оценки взаимо- связи между изучаемыми параметрами были использованы литературные дан- ные, содержащие сведения о массе КДО и древостоя для отдельных пробных площадей. Выявлена положительная (r = 0,57), статистически значимая взаимосвязь между изучаемыми параметрами. Полученные данные можно использовать для уточнения и выведения конверсионных коэффициентов, которые послужат для оценки массы КДО в лесных экосистемах крупных регионов. Structure and stocks of coarse woody debris (CWD) are investigated in the eleven pine forests on European North-East of Russia. Objects under study are differing on forest type and stage of developments. CWD included standing dead trees, fallen dead trees and stumps with a diameter of more than 6 cm. Wood volume and organic matter in separate components of CWD are determined. The mass of CWD depends from stand age. The highest concentrations observed in a overmature pine forest of Myrtillus type but the lowest – in middle-aged stands of Myrtillus and Sphagnosa type. Standing dead trees are noted in all investigated objects. Fallen dead trees and stumps are present in eight stands. These elements are absent in the middle-aged pine stands of Myrtillus and Sphagnosa type. The initial stages of wood destruction dominate in the fallen dead trees. Biomass of stands and it distribution on fractions were present on data that published earlier. The correlation between organic matter mass in CWD and biomass was calculated. It varied in vide range depend on stand age. Literature data were used for estimation relationship between parameters under study. These contained information about forest type, age, CWD mass and stand biomass for separate sample plots. We found positive, statistically significant correlation between CWD stocks and stand biomass. The obtained data can be used to refine and deduce conversion coefficients that will serve to estimate the mass of CWD in forest ecosystems of large regions.

scholarly journals Carbon Emission and Redistribution among Forest Carbon Pools, and Change in Soil Nutrient Content after Different Severities of Forest Fires in Northeast China

Forests ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 110
Author(s):  
Xiaoying Ping ◽  
Yu Chang ◽  
Miao Liu ◽  
Yuanman Hu ◽  
Wentao Huang ◽  
...  
Keyword(s):  
Forest Fires ◽  
Northeast China ◽  
Fire Severity ◽  
Soil Nutrient ◽  
Nutrient Content ◽  
Forest Carbon ◽  
Carbon Pools ◽  
High Severity ◽  
Carbon Transfer ◽  
Carbon Redistribution

Forest fires are a significant factor that affects the boreal forest carbon distribution which emits carbon into the atmosphere and leads to carbon redistribution among carbon pools. However, knowledge about how much carbon was transferred among pools and the immediate changes in soil nutrient contents in areas that were burned by fires of various severities are still limited. In this study, we surveyed eight wildfire sites that are located in northeast China within three months after the fires occurred. Our results indicate that the total soil nitrogen, phosphorus, and organic carbon contents significantly increased after moderate- and high-severity fires. The carbon emissions were 3.84, 5.14, and 12.86 Mg C/ha for low-, moderate-, and high-severity fires, respectively. The amount of carbon transferred among pools increased with fire severity except for the charcoal pool, storing the highest amounts of carbon in moderate-severity fires. Although the charcoal and ash pools accounted for a small proportion of the total ecosystem, they are important for biogeochemical cycles and are worthy of attention. The carbon redistribution information in our study is important for accurately estimating the forest carbon budget and providing crucial parameters for forest carbon cycling models to incorporate the carbon transfer process.

Woodpecker abundance in a logged (40 years ago) vs. unlogged lowland dipterocarp forest in Peninsular Malaysia

2001 ◽  
Vol 17 (2) ◽  
pp. 261-268 ◽  
Author(s):  
A. ROBINSON STYRING ◽  
KALAN ICKES
Keyword(s):  
Forest Type ◽  
Common Species ◽  
Peninsular Malaysia ◽  
Primary Forest ◽  
Dead Trees ◽  
Dipterocarp Forests ◽  
Large Trees ◽  
Significant Difference ◽  
Standing Dead ◽  
Logged Forest

Woodpeckers (Picidae) are a group of birds particularly sensitive to logging and deforestation because they nest in cavities located in large trees and often forage on large trunks or standing dead trees. The diverse woodpecker community of lowland dipterocarp forests in Peninsular Malaysia was investigated in a forest selectively logged 40 y ago and in adjacent primary forest at Pasoh Forest Reserve (PFR). Line transects were conducted at dawn and dusk in each forest type to document potential differences in the woodpecker communities in logged vs. unlogged forest. A total of 121 woodpeckers were recorded along transects, including 14 of the 15 species known to occur at PFR. Eleven species were encountered in logged forest, 12 species were encountered in primary forest, and nine species were found at both sites. A significant difference in the overall woodpecker community between the two forest types was found. Of the most common species, Meiglyptes tristis, Reinwardtipicus validus and Dryocopus javensis were significantly more common in primary forest. Only one species, Picus mentalis, was significantly more abundant in logged forest. Possible causes for the differences observed are discussed.

scholarly journals Classification of Tree Species as Well as Standing Dead Trees Using Triple Wavelength ALS in a Temperate Forest

2019 ◽  
Vol 11 (22) ◽  
pp. 2614 ◽  
Author(s):  
Nina Amiri ◽  
Peter Krzystek ◽  
Marco Heurich ◽  
Andrew Skidmore
Keyword(s):  
Tree Species ◽  
Feature Selection Method ◽  
Silver Fir ◽  
Maximum Point ◽  
Individual Tree ◽  
Dead Trees ◽  
Multi Wavelength ◽  
Standing Dead ◽  
Standing Dead Trees ◽  
532 Nm

Knowledge about forest structures, particularly of deadwood, is fundamental for understanding, protecting, and conserving forest biodiversity. While individual tree-based approaches using single wavelength airborne laserscanning (ALS) can successfully distinguish broadleaf and coniferous trees, they still perform multiple tree species classifications with limited accuracy. Moreover, the mapping of standing dead trees is becoming increasingly important for damage calculation after pest infestation or biodiversity assessment. Recent advances in sensor technology have led to the development of new ALS systems that provide up to three different wavelengths. In this study, we present a novel method which classifies three tree species (Norway spruce, European beech, Silver fir), and dead spruce trees with crowns using full waveform ALS data acquired from three different sensors (wavelengths 532 nm, 1064 nm, 1550 nm). The ALS data were acquired in the Bavarian Forest National Park (Germany) under leaf-on conditions with a maximum point density of 200 points/m 2 . To avoid overfitting of the classifier and to find the most prominent features, we embed a forward feature selection method. We tested our classification procedure using 20 sample plots with 586 measured reference trees. Using single wavelength datasets, the highest accuracy achieved was 74% (wavelength = 1064 nm), followed by 69% (wavelength = 1550 nm) and 65% (wavelength = 532 nm). An improvement of 8–17% over single wavelength datasets was achieved when the multi wavelength data were used. Overall, the contribution of the waveform-based features to the classification accuracy was higher than that of the geometric features by approximately 10%. Our results show that the features derived from a multi wavelength ALS point cloud significantly improve the detailed mapping of tree species and standing dead trees.

scholarly journals Evaluation of the Quality of Irrigation Machinery by Monitoring Changes in the Coefficients of Uniformity and Non-Uniformity of Irrigation

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1499
Author(s):  
Ján Jobbágy ◽  
Peter Dančanin ◽  
Koloman Krištof ◽  
Juraj Maga ◽  
Vlastimil Slaný
Keyword(s):  
Repeated Measurements ◽  
Joint Stock Company ◽  
Stock Company ◽  
Uniformity Coefficient ◽  
Quality Of Work ◽  
Total Length ◽  
Irrigation Uniformity ◽  
Wide Range ◽  
The Impact

Recently, the development of agricultural technology has been focused on achieving higher reliability and quality of work. The aim of the presented paper was to examine the possibilities of evaluating the quality of work of wide-area irrigation machinery by monitoring the coefficients of uniformity and non-uniformity of irrigation. The object of the research was pivot irrigation machinery equipped with sprinklers with a total length from 230 to 540 m. The commonly applied quality of work parameter for wide-range irrigators is the irrigation uniformity coefficient according to Heermann and Hein CUH. Work quality evaluations were also carried out through other parameters applicable in practice, such as irrigation uniformity coefficients calculated according to Christiansen CU, Wilcox and Swailes Cws, and our introduced parameters, the coefficient ar (derived from the degree of unevenness according to Oehler) and the degree of uniformity γr (derived from the degree of non-uniformity according to Voight). Other applied parameters for determining the quality of work of wide-range irrigation machinery were the coefficients of irrigation uniformity according to Hart and Reynolds CUhr, further according to Criddle CUcr and subsequently according to Beale and Howell CUbr. Next, the parameters of the non-uniformity coefficient according to Oehler a, the coefficient of variation according to Stefanelli Cv, the degree of non-uniformity according to Voigt γ and the degree of non-uniformity according to Hofmeister Ef were evaluated. Field tests were performed during the growing season of cultivated crops (potatoes, corn and sugar beet) in the village of Trakovice (agricultural enterprise SLOV-MART, southwest of the Slovakia) and in the district of Piešťany (Agrobiop, joint stock company). During the research, the inlet operating parameters (speed stage, inlet pressure, irrigation dose), technical parameters (number of sprayers, total length, number of chassis) and weather conditions (wind speed and temperature) were recorded. The obtained results were examined by one-way ANOVA analysis depending on the observed coefficient or input conditions and subsequently verified by Tukey and Duncan tests as needed. Irrigation uniformity values ranged from 67.58% (Cws) to 95.88% (CUbh) depending on the input conditions. Irrigation non-uniformity values ranged from 8.58 (a, Ef) to 32.42% (Cv). The results indicate a statistically significant effect of the site of interest and thus the impact of particular field conditions (p < 0.05). When evaluating the application of different coefficients of irrigation uniformity, the results showed a statistically significant effect only in the first test (p = 0.03, p < 0.05). During further repeated measurements, the quality of work increased due to the performed inspection of all sprayers and the reduction in the influence of the wind.

scholarly journals Short-Term Effects of Fire Severity on Vegetation Based on Sentinel-2 Satellite Data

2021 ◽  
Vol 13 (1) ◽  
pp. 432
Author(s):  
Aru Han ◽  
Song Qing ◽  
Yongbin Bao ◽  
Li Na ◽  
Yuhai Bao ◽  
...  
Keyword(s):  
Forest Fire ◽  
Forest Fires ◽  
Vegetation Change ◽  
Fire Severity ◽  
Dynamic Change ◽  
Burned Area ◽  
Fire Event ◽  
Vegetation Dynamic ◽  
Area Index ◽  
Sentinel 2

An important component in improving the quality of forests is to study the interference intensity of forest fires, in order to describe the intensity of the forest fire and the vegetation recovery, and to improve the monitoring ability of the dynamic change of the forest. Using a forest fire event in Bilahe, Inner Monglia in 2017 as a case study, this study extracted the burned area based on the BAIS2 index of Sentinel-2 data for 2016–2018. The leaf area index (LAI) and fractional vegetation cover (FVC), which are more suitable for monitoring vegetation dynamic changes of a burned area, were calculated by comparing the biophysical and spectral indices. The results showed that patterns of change of LAI and FVC of various land cover types were similar post-fire. The LAI and FVC of forest and grassland were high during the pre-fire and post-fire years. During the fire year, from the fire month (May) through the next 4 months (September), the order of areas of different fire severity in terms of values of LAI and FVC was: low > moderate > high severity. During the post fire year, LAI and FVC increased rapidly in areas of different fire severity, and the ranking of areas of different fire severity in terms of values LAI and FVC was consistent with the trend observed during the pre-fire year. The results of this study can improve the understanding of the mechanisms involved in post-fire vegetation change. By using quantitative inversion, the health trajectory of the ecosystem can be rapidly determined, and therefore this method can play an irreplaceable role in the realization of sustainable development in the study area. Therefore, it is of great scientific significance to quantitatively retrieve vegetation variables by remote sensing.

scholarly journals Classifying Forest Type in the National Forest Inventory Context with Airborne Hyperspectral and Lidar Data

2021 ◽  
Vol 13 (10) ◽  
pp. 1863
Author(s):  
Caileigh Shoot ◽  
Hans-Erik Andersen ◽  
L. Monika Moskal ◽  
Chad Babcock ◽  
Bruce D. Cook ◽  
...  
Keyword(s):  
Random Forest ◽  
Forest Inventory ◽  
Forest Type ◽  
Vegetation Indices ◽  
National Forest Inventory ◽  
Classification Algorithm ◽  
Lidar Data ◽  
National Forest ◽  
Interior Alaska ◽  
Type Information

Forest structure and composition regulate a range of ecosystem services, including biodiversity, water and nutrient cycling, and wood volume for resource extraction. Forest type is an important metric measured in the US Forest Service Forest Inventory and Analysis (FIA) program, the national forest inventory of the USA. Forest type information can be used to quantify carbon and other forest resources within specific domains to support ecological analysis and forest management decisions, such as managing for disease and pests. In this study, we developed a methodology that uses a combination of airborne hyperspectral and lidar data to map FIA-defined forest type between sparsely sampled FIA plot data collected in interior Alaska. To determine the best classification algorithm and remote sensing data for this task, five classification algorithms were tested with six different combinations of raw hyperspectral data, hyperspectral vegetation indices, and lidar-derived canopy and topography metrics. Models were trained using forest type information from 632 FIA subplots collected in interior Alaska. Of the thirty model and input combinations tested, the random forest classification algorithm with hyperspectral vegetation indices and lidar-derived topography and canopy height metrics had the highest accuracy (78% overall accuracy). This study supports random forest as a powerful classifier for natural resource data. It also demonstrates the benefits from combining both structural (lidar) and spectral (imagery) data for forest type classification.

scholarly journals Effect of Stem Snapping on Aspen Timber Assortment Recovery in Hemiboreal Forests

Forests ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 28
Author(s):  
Linda Čakša ◽  
Silva Šēnhofa ◽  
Guntars Šņepsts ◽  
Didzis Elferts ◽  
Līga Liepa ◽  
...  
Keyword(s):  
Forest Type ◽  
National Forest Inventory ◽  
Relative Volume ◽  
Individual Tree ◽  
Salvage Logging ◽  
Stem Breakage ◽  
Price Levels ◽  
Value Loss ◽  
The Mean ◽  
Mineral Soils

Post-disturbance salvage logging mitigates economic loss after windthrow, and the value of salvaged timber is strongly linked to its quality and dimensions. We studied the occurrence of wind-induced damage of aspen in the hemiboreal forests of Latvia based on data from the National Forest Inventory and additional measurements. Individual tree data from three re-measurement periods were linked to follow a tree condition (live, broken, uprooted) and to link tree characteristics to a respective snag. Three linear models were developed to assess factors affecting the snapping height. An assortment outcome was calculated for undamaged and salvaged trees using the bucking algorithm, and timber value was calculated at three price levels. Wind-induced damage occurred for 3.4–3.6% of aspen trees, and among these, 45.8–46.6% were broken. The mean height of the broken trees was 27.3 ± 0.9 m, and it was significantly higher (both p < 0.01) compared to the height of undamaged and uprooted trees. The tested models indicated tree height as the main explanatory variable for relative snapping height, with higher trees having a lower point of the stem breakage. The other significant factor was the forest type group, indicating that trees growing on dry mineral soils had lower relative snapping height than trees growing on drained mineral soils. Stem breakage significantly (p < 0.001) reduced the volume of assortments, as compared to the volume of undamaged trees. Relative volume loss of sawlogs showed a logarithmic trend with a steep increase up to snapping height of 6 m, and it correlated tightly (r = 0.83, p < 0.001) with relative value loss of the total stem. Timber value loss had a strong, positive relation to tree diameter at breast height and fluctuated by 0.4% among different price levels. The mean volume reduction was 37.7% for sawlogs, 11.0% for pallet blocks, and 8.9% for technological wood.

scholarly journals Land Cover-Specific Local Incidence Angle Correction: A Method for Time-Series Analysis of Forest Ecosystems

2021 ◽  
Vol 13 (9) ◽  
pp. 1743
Author(s):  
Daniel Paluba ◽  
Josef Laštovička ◽  
Antonios Mouratidis ◽  
Přemysl Štych
Keyword(s):  
Time Series ◽  
Land Cover ◽  
Forest Type ◽  
Incidence Angle ◽  
Correction Method ◽  
Google Earth ◽  
Forest Change ◽  
Corine Land Cover ◽  
Angle Correction ◽  
Wide Range

This study deals with a local incidence angle correction method, i.e., the land cover-specific local incidence angle correction (LC-SLIAC), based on the linear relationship between the backscatter values and the local incidence angle (LIA) for a given land cover type in the monitored area. Using the combination of CORINE Land Cover and Hansen et al.’s Global Forest Change databases, a wide range of different LIAs for a specific forest type can be generated for each scene. The algorithm was developed and tested in the cloud-based platform Google Earth Engine (GEE) using Sentinel-1 open access data, Shuttle Radar Topography Mission (SRTM) digital elevation model, and CORINE Land Cover and Hansen et al.’s Global Forest Change databases. The developed method was created primarily for time-series analyses of forests in mountainous areas. LC-SLIAC was tested in 16 study areas over several protected areas in Central Europe. The results after correction by LC-SLIAC showed a reduction of variance and range of backscatter values. Statistically significant reduction in variance (of more than 40%) was achieved in areas with LIA range >50° and LIA interquartile range (IQR) >12°, while in areas with low LIA range and LIA IQR, the decrease in variance was very low and statistically not significant. Six case studies with different LIA ranges were further analyzed in pre- and post-correction time series. Time-series after the correction showed a reduced fluctuation of backscatter values caused by different LIAs in each acquisition path. This reduction was statistically significant (with up to 95% reduction of variance) in areas with a difference in LIA greater than or equal to 27°. LC-SLIAC is freely available on GitHub and GEE, making the method accessible to the wide remote sensing community.

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