Aboveground biomass distribution of US eastern hardwood forests and the use of large trees as an indicator of forest development

Abstract. Climate change and land-use activities are increasing fire activity across much of the Siberian boreal forest, yet the climate feedbacks from forest disturbances remain difficult to quantify due to limited information on forest biomass distribution, disturbance regimes and post-disturbance ecosystem recovery. Our primary objective here was to analyse post-fire accumulation of Cajander larch (Larix cajanderi Mayr.) aboveground biomass for a 100 000 km2 area of open forest in far northeastern Siberia. In addition to examining effects of fire size and topography on post-fire larch aboveground biomass, we assessed regional fire rotation and density, as well as performance of burned area maps generated from MODIS satellite imagery. Using Landsat imagery, we mapped 116 fire scar perimeters that dated c. 1966–2007. We then mapped larch aboveground biomass by linking field biomass measurements to tree shadows mapped synergistically from WorldView-1 and Landsat 5 satellite imagery. Larch aboveground biomass tended to be low during early succession (≤ 25 yr, 271 ± 26 g m−2, n = 66 [mean ± SE]) and decreased with increasing elevation and northwardly aspect. Larch aboveground biomass tended to be higher during mid-succession (33–38 yr, 746 ± 100 g m−2, n = 32), though was highly variable. The high variability was not associated with topography and potentially reflected differences in post-fire density of tree regrowth. Neither fire size nor latitude were significant predictors of post-fire larch aboveground biomass. Fire activity was considerably higher in the Kolyma Mountains (fire rotation = 110 yr, fire density = 1.0 ± 1.0 fires yr−1 × 104 km−2) than along the forest-tundra border (fire rotation = 792 yr, fire density = 0.3 ± 0.3 fires yr−1 × 104 km−2). The MODIS burned area maps underestimated the total area burned in this region from 2000–2007 by 40%. Tree shadows mapped jointly using high and medium resolution satellite imagery were strongly associated (r2 &approx; 0.9) with field measurements of forest structure, which permitted spatial extrapolation of aboveground biomass to a regional extent. Better understanding of forest biomass distribution, disturbances and post-disturbance recovery is needed to improve predictions of the net climatic feedbacks associated with landscape-scale forest disturbances in northern Eurasia.

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The impact of long dry periods on the aboveground biomass in tropical forests: 20 years of monitoring

10.21203/rs.2.22656/v1 ◽

2020 ◽

Author(s):

Milton Serpa de Meira-Junior ◽

José Roberto Rodrigues Pinto ◽

Natália Oliveira Ramos ◽

Eder Pereira Miguel ◽

Ricardo de Oliveira Gaspar ◽

...

Keyword(s):

Tropical Forests ◽

Aboveground Biomass ◽

Carbon Stocks ◽

Stem Density ◽

Biomass Carbon ◽

Neotropical Forests ◽

Aboveground Carbon ◽

Large Trees ◽

The Impact

Abstract Background Long-term studies of community and population dynamics indicate that abrupt disturbances often catalyse changes in vegetation and carbon stocks. These disturbances include the opening of clearings, flooding, rainfall seasonality, and drought, as well as fire and direct human disturbance. Such events may be super-imposed on longer-term trends in disturbance, such as those associated with climate change (heating, drying), as well as resources. Intact neotropical forests have recently experienced increased drought frequency and fire, on top of pervasive increases in atmospheric CO2 concentrations, but we lack long-term records of responses to such changes especially in the critical transitional areas at the interface of forest and savanna biomes. Here, we present results from 20 years monitoring a valley forest (moist tropical forest outlier) in central Brazil. The forest has experienced multiple drought events and includes plots which have and which have not experienced fire. We focus on how forest structure (stem density and aboveground biomass carbon) and dynamics (stem and biomass mortality and recruitment) have responded to these disturbance regimes. ResultsOverall, the biomass carbon stock increased due to the growth of the trees already present in the forest, without any increase in the overall number of tree stems. Over time, both recruitment and especially mortality of trees tended to increase, and periods of prolonged drought in particular resulted in increased mortality rates of larger trees. This increased mortality was in turn responsible for a decline in aboveground carbon toward the end of the monitoring period. Fire in 2010, which occurred in only some of our plots, tended to exacerbate the trends of increasing mortality and losses of biomass carbon. Conclusion Prolonged droughts influence the mortality of large trees, leading to a decline in aboveground carbon stocks. Here, and in other neotropical forests, recent droughts are capable of shutting down and reversing biomass carbon sinks. These new results add to evidence that anthropogenic climate changes are already adversely impacting tropical forests.

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ALLOMETRIC MODELS FOR ESTIMATING ABOVEGROUND BIOMASS AND BIOMASS ALLOCATION OF CAPIXINGUI TREES (Croton floribundus Spreng.) IN AN AGRISILVICULTURAL SYSTEM

Revista Árvore ◽

10.1590/0100-67622016000200010 ◽

2016 ◽

Vol 40 (2) ◽

pp. 279-288 ◽

Cited By ~ 1

Author(s):

Maria Luiza Franceschi Nicodemo ◽

Marcelo Dias Muller ◽

Antônio Aparecido Carpanezzi ◽

Vanderley Porfírio-da-Silva

Keyword(s):

Aboveground Biomass ◽

Stem Diameter ◽

Distribution Model ◽

Biomass Estimation ◽

Total Biomass ◽

Biomass Distribution ◽

Residual Distribution ◽

Allometric Models ◽

Crown Diameter ◽

Bole Biomass

ABSTRACT The objective of this study was to select allometric models to estimate total and pooled aboveground biomass of 4.5-year-old capixingui trees established in an agrisilvicultural system. Aboveground biomass distribution of capixingui was also evaluated. Single- (diameter at breast height [DBH] or crown diameter or stem diameter as the independent variable) and double-entry (DBH or crown diameter or stem diameter and total height as independent variables) models were studied. The estimated total biomass was 17.3 t.ha-1, corresponding to 86.6 kg per tree. All models showed a good fit to the data (R2ad > 0.85) for bole, branches, and total biomass. DBH-based models presented the best residual distribution. Model lnW = b0 + b1* lnDBH can be recommended for aboveground biomass estimation. Lower coefficients were obtained for leaves (R2ad > 82%). Biomass distribution followed the order: bole>branches>leaves. Bole biomass percentage decreased with increasing DBH of the trees, whereas branch biomass increased.

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Supplementary material to "Canopy Area of Large Trees Explains Aboveground Biomass Variations across Nine Neotropical Forest Landscapes"

10.5194/bg-2017-547-supplement ◽

2018 ◽

Author(s):

Victoria Meyer ◽

Sassan Saatchi ◽

David B. Clark ◽

Michael Keller ◽

Grégoire Vincent ◽

...

Keyword(s):

Aboveground Biomass ◽

Neotropical Forest ◽

Large Trees ◽

Canopy Area ◽

Supplementary Material

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Tree Communities and Aboveground Biomass in the Submontane Zone of Ketambe Resort, Mount Leuser National Park, Aceh

Elkawnie ◽

10.22373/ekw.v6i2.7991 ◽

2020 ◽

Vol 6 (2) ◽

pp. 237

Author(s):

Taufikurrahman Nasution ◽

Muhammad Efendi

Keyword(s):

Aboveground Biomass ◽

National Park ◽

Secondary Forest ◽

Cultivated Plants ◽

Conservation Areas ◽

Tree Structures ◽

Large Trees ◽

Tree Communities ◽

Shorea Platyclados ◽

Average Wood

Abstract: Mount Leuser National Park is one of the largest conservation areas and plays important ecological and economic functions. To support forest management, it is important to gain current vegetation data. The sampling method of a 0.1 hectare plot was carried out on two sampling sites in the submontane zone of Ketambe Resort, Mount Leuser National Park, Aceh. The diversity of trees was not significantly different, while species composition was different. Site one was dominated by Syzygium spp. and Shorea platyclados, while site two was dominated by Altingia excelsa and Bridelia glauca. Lauraceae, Myrtaceae, and Dipterocarpace families dominated in both sites. Tree structures formed three strata and showed a good capacity for forest regeneration. The aboveground biomass of site one was higher than site two due to the presence of more large trees. Pioneer species, cultivated plants, a low average wood density, and low aboveground biomass indicated secondary forest characteristics in both sites. Abstrak: Taman Nasional Gunung Leuser merupakan salah satu kawasan konservasi yang terluas dan memiliki fungsi ekologi dan ekonomi yang penting. Data vegetasi terkini penting didapatkan untuk mendukung pengelolaan hutan. Metode sampling dengan plot 0.1 hektar dilakukan di dua lokasi pada zona submontana Resort Ketambe, Taman Nasional Gunung Leuser, Aceh. Keanekaragaman jenis pohon tidak berbeda secara nyata sementara komposisi jenis berbeda. Lokasi satu didominasi oleh Syzygium spp. dan Shorea platyclados, sementara lokasi dua didominasi oleh Altingia excelsa dan Bridelia glauca. Suku Lauraceae, Myrtaceae dan Dipterocarpace mendominasi pada kedua lokasi. Struktur pohon membentuk tiga strata dan menunjukkan kemampuan regenerasi hutan yang baik. Biomassa pohon di atas permukaan pada lokasi satu lebih tinggi dibandingkan lokasi dua karena lebih banyaknya pohon berukuran besar. Jenis pionir, tanaman budidaya, rata-rata berat jenis kayu dan biomassa di atas permukaan yang rendah mengindikasikan karakteristik hutan sekunder pada kedua lokasi.

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Quantifying the Spatial Heterogeneity and Driving Factors of Aboveground Forest Biomass in the Urban Area of Xi’an, China

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi9120744 ◽

2020 ◽

Vol 9 (12) ◽

pp. 744

Author(s):

Xuan Zhao ◽

Jianjun Liu ◽

Hongke Hao ◽

Yanzheng Yang

Keyword(s):

Spatial Distribution ◽

Urban Area ◽

Aboveground Biomass ◽

Tree Species ◽

City Planning ◽

Urban Forest ◽

Forest Biomass ◽

Q Value ◽

Biomass Distribution ◽

Land Type

Investigating the spatial distribution of urban forest biomass and its potential influencing factors would provide useful insights for configuring urban greenspace. Although China is experiencing an unprecedented scale of urbanization, the spatial pattern of the urban forest biomass distribution as a critical component in the urban landscape has not been fully examined. Using the geographic detector method, this research examines the impacts of four geographical factors (GFs)—dominant tree species, forest categories, land types, and age groups—on the aboveground biomass distribution of urban forests in 1480 plots in Xi’an, China. The results indicate that (1) the aboveground biomass and four GFs show obvious heterogeneity regarding their spatial distribution in Xi’an; (2) the dominant tree species and age group which impacts the patterns of aboveground biomass are the primary GFs, with the independent q value (a statistic metric used to quantify the impacts of GFs in this study) reaching 0.595 and 0.202, respectively, while the forest category and land type were weakly linked to the spatial variation of aboveground biomass, with a q value of 0.087 and 0.076, respectively; and (3) the interactions among these four GFs also tend to contribute to the distribution pattern of aboveground biomass. The interactions between GFs achieved a larger impact than the sum of impacts that were independently obtained from the factors. Our results showed that the method of using a geographical detector is a useful tool in the urban area, and can reveal the driver pattern of aboveground biomass and provide a reference for city planning and management.

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Canopy area of large trees explains aboveground biomass variations across neotropical forest landscapes

Biogeosciences ◽

10.5194/bg-15-3377-2018 ◽

2018 ◽

Vol 15 (11) ◽

pp. 3377-3390 ◽

Cited By ~ 16

Author(s):

Victoria Meyer ◽

Sassan Saatchi ◽

David B. Clark ◽

Michael Keller ◽

Grégoire Vincent ◽

...

Keyword(s):

Forest Structure ◽

Aboveground Biomass ◽

Tree Mortality ◽

Forest Disturbance ◽

Basal Area ◽

Selective Logging ◽

Tree Canopy ◽

Crown Area ◽

Large Trees ◽

Canopy Area

Abstract. Large tropical trees store significant amounts of carbon in woody components and their distribution plays an important role in forest carbon stocks and dynamics. Here, we explore the properties of a new lidar-derived index, the large tree canopy area (LCA) defined as the area occupied by canopy above a reference height. We hypothesize that this simple measure of forest structure representing the crown area of large canopy trees could consistently explain the landscape variations in forest volume and aboveground biomass (AGB) across a range of climate and edaphic conditions. To test this hypothesis, we assembled a unique dataset of high-resolution airborne light detection and ranging (lidar) and ground inventory data in nine undisturbed old-growth Neotropical forests, of which four had plots large enough (1 ha) to calibrate our model. We found that the LCA for trees greater than 27 m (∼ 25–30 m) in height and at least 100 m2 crown size in a unit area (1 ha), explains more than 75 % of total forest volume variations, irrespective of the forest biogeographic conditions. When weighted by average wood density of the stand, LCA can be used as an unbiased estimator of AGB across sites (R2 = 0.78, RMSE = 46.02 Mg ha−1, bias = −0.63 Mg ha−1). Unlike other lidar-derived metrics with complex nonlinear relations to biomass, the relationship between LCA and AGB is linear and remains unique across forest types. A comparison with tree inventories across the study sites indicates that LCA correlates best with the crown area (or basal area) of trees with diameter greater than 50 cm. The spatial invariance of the LCA–AGB relationship across the Neotropics suggests a remarkable regularity of forest structure across the landscape and a new technique for systematic monitoring of large trees for their contribution to AGB and changes associated with selective logging, tree mortality and other types of tropical forest disturbance and dynamics.

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Allometric Biomass Models for European Beech and Silver Fir: Testing Approaches to Minimize the Demand for Site-Specific Biomass Observations

Forests ◽

10.3390/f11111136 ◽

2020 ◽

Vol 11 (11) ◽

pp. 1136

Author(s):

Ioan Dutcă ◽

Dimitris Zianis ◽

Ion Cătălin Petrițan ◽

Cosmin Ion Bragă ◽

Gheorghe Ștefan ◽

...

Keyword(s):

Aboveground Biomass ◽

European Beech ◽

Silver Fir ◽

Allometric Model ◽

Site Specific ◽

Biomass Models ◽

Large Trees ◽

Wide Range ◽

Local Sample ◽

Specific Biomass

In this paper, site-specific allometric biomass models were developed for European beech (Fagus sylvatica L.) and silver fir (Abies alba Mill.) to estimate the aboveground biomass in Șinca virgin forest, Romania. Several approaches to minimize the demand for site-specific observations in allometric biomass model development were also investigated. Developing site-specific allometric biomass models requires new measurements of biomass for a sample of trees from that specific site. Yet, measuring biomass is laborious, time consuming, and requires extensive logistics, especially for very large trees. The allometric biomass models were developed for a wide range of diameters at breast height, D (6–86 cm for European beech and 6–93 cm for silver fir) using a logarithmic transformation approach. Two alternative approaches were applied, i.e., random intercept model (RIM) and a Bayesian model with strong informative priors, to enhance the information of the site-specific sample (of biomass observations) by supplementing with a generic biomass sample. The appropriateness of each model was evaluated based on the aboveground biomass prediction of a 1 ha sample plot in Șinca forest. The results showed that models based on both D and tree height (H) to predict tree aboveground biomass (AGB) were more accurate predictors of AGB and produced plot-level estimates with better precision, than models based on D only. Furthermore, both RIM and Bayesian approach performed similarly well when a small local sample (of seven smallest trees) was used to calibrate the allometric model. Therefore, the generic biomass observations may effectively be combined with a small local sample (of just a few small trees) to calibrate an allometric model to a certain site and to minimize the demand for site-specific biomass measurements. However, special attention should be given to the H-D ratio, since it can affect the allometry and the performance of the reduced local sample approach.

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Growth responses of trees and understory plants to nitrogen fertilization in a subtropical forest in China

Biogeosciences ◽

10.5194/bg-14-3461-2017 ◽

2017 ◽

Vol 14 (14) ◽

pp. 3461-3469 ◽

Cited By ~ 18

Author(s):

Di Tian ◽

Peng Li ◽

Wenjing Fang ◽

Jun Xu ◽

Yongkai Luo ◽

...

Keyword(s):

Aboveground Biomass ◽

Basal Area ◽

Ground Cover ◽

N Fertilization ◽

Subtropical Forest ◽

Growth Responses ◽

Understory Plants ◽

Large Trees ◽

N Enrichment ◽

Understory Shrubs

Abstract. Reactive nitrogen (N) increase in the biosphere has been a noteworthy aspect of global change, producing considerable ecological effects on the functioning and dynamics of the terrestrial ecosystems. A number of observational studies have explored responses of plants to experimentally simulated N enrichment in boreal and temperate forests. Here we investigate how the dominant trees and different understory plants respond to experimental N enrichment in a subtropical forest in China. We conducted a 3.4-year N fertilization experiment in an old-aged subtropical evergreen broad-leaved forest in eastern China with three treatment levels applied to nine 20 m  ×  20 m plots and replicated in three blocks. We divided the plants into trees, saplings, shrubs (including tree seedlings), and ground-cover plants (ferns) according to the growth forms, and then measured the absolute and relative basal area increments of trees and saplings and the aboveground biomass of understory shrubs and ferns. We further grouped individuals of the dominant tree species, Castanopsis eyrei, into three size classes to investigate their respective growth responses to the N fertilization. Our results showed that the plot-averaged absolute and relative growth rates of basal area and aboveground biomass of trees were not affected by N fertilization. Across the individuals of C. eyrei, the small trees with a DBH (diameter at breast height) of 5–10 cm declined by 66.4 and 59.5 %, respectively, in N50 (50 kg N ha−1 yr−1) and N100 fertilized plots (100 kg N ha−1 yr−1), while the growth of median and large trees with a DBH of >  10 cm did not significantly change with the N fertilization. The growth rate of small trees, saplings, and the aboveground biomass of understory shrubs and ground-cover ferns decreased significantly in the N-fertilized plots. Our findings suggested that N might not be a limiting nutrient in this mature subtropical forest, and that the limitation of other nutrients in the forest ecosystem might be aggravated by the enhanced N availability, potentially resulting in an adverse effect on the development of natural subtropical forest.

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