scholarly journals Megaherbivores modify forest structure and increase carbon stocks through multiple pathways

2021 ◽  
Author(s):  
Fabio Berzaghi ◽  
Francois Bretagnolle ◽  
Clementine Durand-Bessart ◽  
Stephen Blake
Keyword(s):  
Wood Density ◽  
Carbon Stocks ◽  
Climate Mitigation ◽  
Regeneration Failure ◽  
Elephant Conservation ◽  
Mode Loss ◽  
Forest Elephants ◽  
Forest Elephant ◽  
Nutritional Data ◽  
Average Wood

Megaherbivores have pervasive ecological effects. In African rainforests, elephants can increase aboveground carbon, though the mechanisms are unclear. Here we combine a large unpublished dataset of forest elephant feeding with published browsing preferences totaling > 120,000 records covering 700 plant species, including nutritional data for 102 species. Elephants increase carbon stocks by: 1) promoting high wood density tree species via preferential browsing on leaves from low wood density species, which are more digestible; 2) dispersing seeds of trees that are relatively large and have the highest average wood density among tree guilds based on dispersal mode. Loss of forest elephants could cause a 5-12% decline in carbon stocks due to regeneration failure of elephant-dispersed trees and an increase in abundance of low wood density trees. These results show the major importance of megaherbivores in maintaining diverse, high-carbon tropical forests. Successful elephant conservation will contribute to climate mitigation at a scale of global relevance.

scholarly journals Forests: Carbon sequestration, biomass energy, or both?

2020 ◽  
Vol 6 (13) ◽  
pp. eaay6792 ◽  
Author(s):  
Alice Favero ◽  
Adam Daigneault ◽  
Brent Sohngen
Keyword(s):  
Carbon Sequestration ◽  
Carbon Balance ◽  
Carbon Stocks ◽  
Forest Carbon ◽  
Biomass Energy ◽  
Climate Mitigation ◽  
Intensive Management ◽  
Natural Forests ◽  
Timber Management ◽  
Forest Carbon Sequestration

There is a continuing debate over the role that woody bioenergy plays in climate mitigation. This paper clarifies this controversy and illustrates the impacts of woody biomass demand on forest harvests, prices, timber management investments and intensity, forest area, and the resulting carbon balance under different climate mitigation policies. Increased bioenergy demand increases forest carbon stocks thanks to afforestation activities and more intensive management relative to a no-bioenergy case. Some natural forests, however, are converted to more intensive management, with potential biodiversity losses. Incentivizing both wood-based bioenergy and forest sequestration could increase carbon sequestration and conserve natural forests simultaneously. We conclude that the expanded use of wood for bioenergy will result in net carbon benefits, but an efficient policy also needs to regulate forest carbon sequestration.

Nutritional ecology of elephants in Kibale National Park, Uganda, and its relationship with crop-raiding behaviour

2006 ◽  
Vol 22 (4) ◽  
pp. 441-449 ◽  
Author(s):  
Karyn D. Rode ◽  
Patrick I. Chiyo ◽  
Colin A. Chapman ◽  
Lee R. McDowell
Keyword(s):  
National Park ◽  
Nutritional Ecology ◽  
Secondary Compounds ◽  
Kibale National Park ◽  
Crop Raiding ◽  
Mineral Concentration ◽  
Low Sodium ◽  
Dietary Nutrient ◽  
Forest Elephants ◽  
Forest Elephant

This study investigated the nutritional ecology of forest elephants in Kibale National Park, Uganda relative to crop-raiding behaviour, and examined nutritional differences between crops and food consumed by wild elephants. An index of dietary nutrient concentration was determined by quantifying the species and parts of plants consumed along feeding trails, collecting food items, and analysing foods for energy, fibre, protein, minerals and secondary compounds. Frequency of crop raiding was quantified over 13 mo. Energy and protein concentration was within suggested levels, but concentrations of several minerals, particularly sodium, were low relative to requirements based on captive elephants and values reported for other wild populations. The very low sodium concentrations of Kibale elephant diets and low availability of alternative sodium sources, such as soil or water, suggest that sodium drive is very likely in this population. Crops consumed by Kibale elephants had higher Na concentrations and lower concentrations of fibre and secondary compounds than wild diets. The known attraction of elephants to mineral sources throughout their range and the low mineral concentration of leaves, fruits, bark, and stems consumed by forest elephant in this study suggest that mineral nutrition is likely to be an important factor driving elephant behaviour and patterns of habitat use.

Wood density of western hemlock: effect of ring width

1994 ◽  
Vol 24 (3) ◽  
pp. 638-641 ◽  
Author(s):  
Jeffrey D. DeBell ◽  
John C. Tappeiner II ◽  
Robert L. Krahmer
Keyword(s):  
Growth Rate ◽  
Wood Density ◽  
Growth Rates ◽  
Ring Width ◽  
Western Hemlock ◽  
X Ray ◽  
Breast Height ◽  
Latewood Density ◽  
Earlywood Width ◽  
Average Wood

Wood density of western hemlock (Tsugaheterophylla (Raf.) Sarg.) was determined by X-ray densitometry of strips from breast-height samples consisting of rings 20–24 from the pith. Ring parameters were averaged over the 5 years for each strip. Wood density was negatively correlated with radial growth rate. Average wood density dropped from 0.47 to 0.37 g/cm3 as average ring width increased from 2 to 8 mm. Wood density decreased at higher growth rates primarily because earlywood width increased while latewood width remained the same; as a result, percentage of latewood decreased. Earlywood density decreased slightly at higher growth rates, but latewood density was not significantly related to growth rate.

scholarly journals Carbon Stocks and Accumulation Rates in Salt Marshes of the Pacific Coast of Canada

2018 ◽  
Author(s):  
Stephen G. Chastain ◽  
Karen Kohfeld ◽  
Marlow G. Pellatt
Keyword(s):  
Salt Marsh ◽  
Salt Marshes ◽  
Pacific Coast ◽  
Carbon Stocks ◽  
Carbon Accumulation ◽  
Climate Mitigation ◽  
Accumulation Rates ◽  
The Pacific ◽  
Clayoquot Sound ◽  
Carbon Accumulation Rates

Abstract. Tidal salt marshes are known to accumulate blue carbon at high rates relative to their surface area and have been put forth as a potential means for enhanced CO2 sequestration. However, estimates of salt marsh carbon accumulation rates are based on a limited number of marshes globally and the estimation of carbon accumulation rates require detailed dating to provide accurate estimates. We address one data gap along the Pacific Coast of Canada by estimating carbon stocks in 34 sediment cores and estimating carbon accumulation rates using 210Pb dating on four cores from seven salt marshes within the Clayoquot Sound UNESCO Biosphere Reserve and Pacific Rim National Park Reserve of Canada (49.2° N, 125.80° W). Carbon stocks averaged 80.6 ± 43.8 megagrams of carbon per hectare (Mg C ha−1) between the seven salt marshes, and carbon accumulation rates averaged 146 ± 102 grams carbon per square meter per year (g C m−2 yr−1). These rates are comparable to those found in salt marshes further south along the Pacific coast of North America (32.5–38.2° N) and at similar latitudes in Eastern Canada and Northern Europe (43.6–55.5° N). The seven Clayoquot Sound salt marshes currently accumulate carbon at a rate of 54.28 Mg C yr−1 over an area of 46.94 ha, 87 % of which occurs in the high marsh zone. On a per-hectare basis, Clayoquot Sound salt marsh soils accumulate carbon at least one order of magnitude more quickly than the average of global boreal forest soils, and approximately two times larger than rates for forests in British Columbia. However, because of their relatively small area, we suggest that their carbon accumulation rate capacity could best be considered as a climate mitigation co-benefit when conserving for other salt marsh ecosystem services.

scholarly journals Estimation of biomass and carbon stocks: the case of the Atlantic Forest

2008 ◽  
Vol 8 (2) ◽  
pp. 21-29 ◽  
Author(s):  
Simone Aparecida Vieira ◽  
Luciana Ferreira Alves ◽  
Marcos Aidar ◽  
Luciana Spinelli Araújo ◽  
Tim Baker ◽  
...  
Keyword(s):  
Atlantic Forest ◽  
Wood Density ◽  
Rain Forest ◽  
Floristic Composition ◽  
Dry Weight ◽  
Carbon Stocks ◽  
Atlantic Rain Forest ◽  
Main Question ◽  
Tree Biomass ◽  
Serra Do Mar

The main objective of this paper is to present and discuss the best methods to estimate live above ground biomass in the Atlantic Forest. The methods presented and conclusions are the products of a workshop entitled "Estimation of Biomass and Carbon Stocks: the Case of Atlantic Rain Forest". Aboveground biomass (AGB) in tropical forests is mainly contained in trees. Tree biomass is a function of wood volume, obtained from the diameter and height, architecture and wood density (dry weight per unit volume of fresh wood). It can be quantified by the direct (destructive) or indirect method where the biomass quantification is estimated using mathematical models. The allometric model can be site specific when elaborated to a particular ecosystem or general that can be used in different sites. For the Atlantic Forest, despite the importance of it, there are only two direct measurements of tree biomass, resulting in allometric models specific for this ecosystem. To select one or other of the available models in the literature to estimate AGB it is necessary take into account what is the main question to be answered and the ease with which it is possible to measure the independent variables in the model. Models that present more accurate estimates should be preferred. However, more simple models (those with one independent variable, usually DBH) can be used when the focus is monitoring the variation in carbon storage through the time. Our observations in the Atlantic Forest suggest that pan-tropical relations proposed by Chave et al. (2005) can be confidently used to estimated tree biomass across biomes as long as tree diameter (DBH), height, and wood density are accounted for in the model. In Atlantic Forest, we recommend the quantification of biomass of lianas, bamboo, palms, tree ferns and epiphytes, which are an important component in this ecosystem. This paper is an outcome of the workshop entitled "Estimation of Biomass and Carbon Stocks: the Case of Atlantic Rain Forest", that was conducted at Ubatuba, São Paulo, Brazil, between 4 and 8 December 2006 as part of the Brazilian project "Ombrophylus Dense Forest floristic composition, structure and function at the Núcleos Picinguaba and Santa Virginia of the Serra do Mar State Park", BIOTA Gradiente.

scholarly journals Combining local knowledge and occupancy analysis for a rapid assessment of the forest elephant Loxodonta cyclotis in Cameroon's timber production forests

Oryx ◽  
2018 ◽  
Vol 54 (1) ◽  
pp. 90-100 ◽  
Author(s):  
Stephanie Brittain ◽  
Madeleine Ngo Bata ◽  
Paul De Ornellas ◽  
E. J. Milner-Gulland ◽  
Marcus Rowcliffe
Keyword(s):  
Large Scale ◽  
Population Change ◽  
Demographic Data ◽  
Rapid Assessment ◽  
Occupancy Models ◽  
Spatial And Temporal Patterns ◽  
Conservation Action ◽  
Forest Elephants ◽  
Loxodonta Cyclotis ◽  
Forest Elephant

AbstractInformation on the distribution and abundance of the forest elephant Loxodonta cyclotis is needed to allocate limited resources appropriately and set conservation goals for the species. However, monitoring at large scales in forest habitats is complicated, expensive and time consuming. We investigated the potential of applying interview-based occupancy analysis as a tool for the rapid assessment of the distribution and relative abundance of forest elephants in eastern Cameroon. Using single-season occupancy models, we explored the covariates that affect forest elephant occupancy and detectability, and identified spatial and temporal patterns in population change and occupancy. Quantitative and qualitative socio-demographic data offer additional depth and understanding, placing the occupancy analysis in context and providing valuable information to guide conservation action. Detectability of forest elephants has decreased since 2008, which is consistent with the decline in perceived abundance in occupied sites. Forest elephants occupy areas outside protected areas and outside the known elephant range defined by IUCN. Critical conservation attention is required to assess forest elephant populations and the threats they face in these poorly understood areas. Interview-based occupancy analysis is a reliable and suitable method for a rapid assessment of forest elephant occupancy on a large scale, as a complement to, or the first stage in, a monitoring process.

scholarly journals Understanding the variation in wood densities of trees and its implications for carbon assessments

2019 ◽  
Author(s):  
Karthik Teegalapalli ◽  
Chandan Kumar Pandey ◽  
Anand M Osuri ◽  
Jayashree Ratnam ◽  
Mahesh Sankaran
Keyword(s):  
Intraspecific Variation ◽  
Wood Density ◽  
Aboveground Biomass ◽  
Spatial Scales ◽  
Regional Scale ◽  
Interspecific Variation ◽  
Carbon Stocks ◽  
Biomass Estimation ◽  
Continental Scale ◽  
Genus Level

AbstractWood density is a key functional trait used to estimate aboveground biomass (AGB) and carbon stocks. A common practice in forest AGB and carbon estimation is to substitute genus averages (across species with known wood densities) in cases where wood densities of particular species are unknown. However, the extent to which genus-level averages are reflective of species wood densities across tree genera is uncertain, and understanding this is critical for estimating the accuracy of carbon stock estimates. Using primary field data from India and secondary data from a published global dataset, we quantified the extent to which wood density varied among individuals within species (intraspecific variation) at the regional scale and among species within genera (interspecific variation) at regional to global scales. We used a published global database with wood density data for 7743 species belonging to 1741 genera. Linear models were used to compare the species values with the genera averages and the individual values with the species averages, respectively. To estimate the error associated with using genus-level averages for carbon stocks estimation, we compared genus values averaged at the global, old world and continental scales with species values from actually measured data. We also ran a simulation using vegetation data from a published database to calculate the estimation errors in a 1 hectare plot level when genera-averaged wood densities are used. Intraspecific variation was significantly lower than interspecific variation. Continental level genera averages led to estimates closer to the species values for the 10 genera for which most data on species was available. This was also evident from a comparison of genera averages at these three spatial scales with species values from our data. Species within certain ‘hypervarying’ genera showed relatively high levels of variation, irrespective of the spatial scale of the dataset used. The error in estimation of AGB when genera-averaged values were used for species wood densities was 0.35, 0.71 and 2.43% when 0, 10 and 25% of the girth of the trees in the simulated plot were from hypervariable genera. Our findings indicate that species values provide the most accurate estimates for individuals. Genus average wood density values at the continental scale provided more reliable estimates than those at larger spatial scales. The aboveground biomass estimation error when species wood densities were approximated to the genera-average values was 1.4 to 3.7 tonnes per ha when 10% and 25%, respectively, of the girth of trees was from species from hypervariable genera. Our findings indicate that regional or continental scale genera averages provide more reliable estimates than global data and we propose a method to identify hypervariable genera, for which species values rather than genera averages can provide better estimates of carbon stocks.

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