Stock Estimates Research Articles

Revealing the hidden carbon in forested wetland soils

Inland wetlands are critical carbon reservoirs storing 30% of global soil organic carbon (SOC) within 6% of the land surface. However, forested regions contain SOC-rich wetlands that are not included in current maps, which we refer to as ‘cryptic carbon’. Here, to demonstrate the magnitude and distribution of cryptic carbon, we measure and map SOC stocks as a function of a continuous, upland-to-wetland gradient across the Hoh River Watershed (HRW) in the Pacific Northwest of the U.S., comprising 68,145 ha. Total catchment SOC at 30 cm depth (5.0 TgC) is between estimates from global SOC maps (GSOC: 3.9 TgC; SoilGrids: 7.8 TgC). For wetland SOC, our 1 m stock estimates are substantially higher (Mean: 259 MgC ha−1; Total: 1.7 TgC) compared to current wetland-specific SOC maps derived from a combination of U.S. national datasets (Mean: 184 MgC ha−1; Total: 0.3 TgC). We show that total unmapped or cryptic carbon is 1.5 TgC and when added to current estimates, increases the estimated wetland SOC stock to 1.8 TgC or by 482%, which highlights the vast stores of SOC that are not mapped and contained in unprotected and vulnerable wetlands.

A new approach to assessing and forecasting the stock of sprat in the Baltic Sea in modern conditions

The aim of this article: analysis of information and software for forecasting of the Baltic Sea sprat stock Sprattus sprattus balticus at 22–32 ICES subdivisions in the context of the suspension of Russia’s activities in the International Council for the Exploration of the Sea (ICES).Methods used: The data of estimates of sprat abundance and biomass by hydroacoustic methods, commercial and biostatistical characteristics of the species were used to assess the stock and predict its catch in the Baltic Sea. Estimation of the sprat stock was carried out using the traditional method of virtual population analysis (VPA) adjusted according to the method of extended survival analysis (XSA) using the internationally approved VPA module software within the framework of ICES and the R software environment. The recruitment calibration program RCT3 (Recruitment calibration) was used for the abundance of recruitment (age 1 year) according to XSA and forecast. A multivariate short-term forecast was carried out at different levels of development of the total allowable catch (TAC) under the MFDP program (Multi Fleet Deterministic Projection). As an alternative, the domestic software «KAFKA» was tested.Novelty: for the first time, estimates of the sprat stock were made in the conditions of limited access of Russian specialists to primary data in ICES in full.Result: modern methodological and informational support of scientific research in the Baltic Sea in the conditions of the suspension of the activities of Russian experts in ICES makes it possible to obtain information in the minimum necessary amount for assessing the stock of sprat and predicting its catch. Modeling with the «KAFKA» software showed satisfactory results.Practical significance: The current level of information support for forecasting the state of the stock and catch of sprat in the Baltic Sea will allow solving a complex of problems of managing this resource in modern conditions.

A Proposed Methodology for Determining the Economically Optimal Number of Sample Points for Carbon Stock Estimation in the Canadian Prairies

Soil organic carbon (SOC) sequestration assessment requires accurate and effective tools for measuring baseline SOC stocks. An emerging technique for estimating baseline SOC stocks is predictive soil mapping (PSM). A key challenge for PSM is determining sampling density requirements, specifically, determining the economically optimal number of samples for predictive soil mapping for SOC stocks. In an attempt to answer this question, data were used from 3861 soil organic carbon samples collected as part of routine agronomic soil testing from a 4702 ha farming operation in Saskatchewan, Canada. A predictive soil map was built using all the soil data to calculate the total carbon stock for the entire study area. The dataset was then subset using conditioned Latin hypercube sampling (cLHS), both conventional and stratified by slope position, to determine the total carbon stocks with the following sampling densities (points per ha): 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, and 0.8. A nonlinear error function was then fit to the data, and the optimal number of samples was determined based on the number of samples that minimized soil data costs and the value of the soil carbon stock prediction error. The stratified cLHS required fewer samples to achieve the same level of accuracy compared to conventional cLHS, and the optimal number of samples was more sensitive to carbon price than sampling costs. Overall, the optimal sampling density ranged from 0.025 to 0.075 samples per hectare.

The Abundance оf Black Grouse in Northern Eurasia

This paper presents the estimate results of the average annual abundance of black grouse (Lyrurus tetrix L., 1758), made on the material of data bank (ISEA SB RAS) for groups of physico-geographical countries within the borders of the USSR 1990. On the East European and West Siberian plains, value of grouse abundance and total number were calculated on average separately for the first and second half of summer and in winter, mainly from 1960 to 2020, for physicogeographical countries – only for the first half of summer. The under-accounting of birds was revealed in the second half of summer on the both plains territory, which was made up with the help of additional calculations. As a result, value of the abundance and total number of birds were obtained for natural zones and subzones within Russia and the USSR, separately on the East European and West Siberian plains. A significant similarity of the grouse stock estimation results by weighted averages, separately by landscape groups, and by a simple average for the entire territory of a physico-geographical country or several of them in the first half of summer is shown. The second method of stock assessment compared with the first one gave results that differ for those plains within confidence intervals at a confidence level of 0.1. On the groups of physico-geographical countries territories in the first half of summer, the highest average annual values of the abundance and number of black grouse are appropriate of the European territory and the Urals as a whole, as well as in Western Siberia. The lowest values are typical for Central Asia and Kazakhstan.

Deep point cloud regression for above-ground forest biomass estimation from airborne LiDAR

Quantifying forest biomass stocks and their dynamics is important for implementing effective climate change mitigation measures by aiding local forest management, studying processes driving af-, re-, and deforestation, and improving the accuracy of carbon accounting. Owing to the 3-dimensional nature of forest structure, remote sensing using airborne LiDAR can be used to perform these measurements of vegetation structure at large scale. Harnessing the full dimensionality of the data, we present deep learning systems predicting wood volume and above ground biomass (AGB) directly from the full LiDAR point cloud and compare results to state-of-the-art approaches operating on basic statistics of the point clouds. For this purpose, we devise different neural network architectures for point cloud regression and evaluate them on remote sensing data of areas for which AGB estimates have been obtained from field measurements in the Danish national forest inventory. Our adaptation of Minkowski convolutional neural networks for regression give the best results. The deep neural networks produce significantly more accurate wood volume, AGB, and carbon stock estimates compared to state-of-the-art approaches. In contrast to other methods, the proposed deep learning approach does not require a digital terrain model and is robust to artifacts along the boundaries of the evaluated areas, which we demonstrate for the case where trees protrude into the area from the outside. We expect this finding to have a strong impact on LiDAR-based analyses of biomass dynamics.

Developing crown width model for mixed forests using soil, climate and stand factors

Abstract The tree crown is a useful measure of tree vigour and is highly relevant to a tree's environmental adaptability. Crown allometry depends on environmental and stand conditions. Several studies have focussed on the effects of climate change and competitive intensity on the crown, but the regulatory role of soil resources and diversity on crown allometry and carbon allocation has been neglected. Data from 20,994 trees in 232 mixed forests collected between 2011 and 2019 were located near four major mountain ranges in northeast China. The proposed crown width model includes the stand developmental stage, soil, climate, competition intensity, species mixture, species diversity, structural diversity and their interactions. We observed that the cross‐species allometric scaling exponent does not conform to the universal scaling law. Our results showed that crown width increased with increasing soil bulk density, quadratic mean diameter and coefficient of diameter variation but decreased with increasing de Martonne aridity index, basal area, Simpson index and species mixture. The interaction between quadratic mean diameter and soil bulk density had a significant negative effect on crown width. The influence of a particular factor within the interaction term on crown width was modulated by the gradients of other factors. Furthermore, soil bulk density contributed more to crown width modelling than the aridity index, and structural diversity had a greater effect on crown width than species diversity. Synthesis. Our results provide new insights into the environmental variability of crown allometry in mixed forests under global change, which is critical for improving regional and global estimates of forest biomass and carbon stocks.

Estimation of stock and recruitment curve of the Tsushima Warm Current stock of Japanese anchovy <i>Engraulis japonicus</i> incorporating the effect of capture of whitebait into the mortality process

Estimation of stock and recruitment curve of the Tsushima Warm Current stock of Japanese anchovy <i>Engraulis japonicus</i> incorporating the effect of capture of whitebait into the mortality process

Estimation of carbon stock in mixed garden tree stands in Jatigede Subdistrict, Sumedang Regency using NDVI (Normalized Difference Vegetation Index)

Carbon dioxide (CO2) is the most significant greenhouse gas causing global warming. Mixed gardens are one type of artificial vegetation in Indonesia that helps to mitigate global warming. The construction of Jatigede Reservoir leads to a reduction in agricultural area and plant cover, affecting tree stands' ability to absorb CO2 from the atmosphere. Remote sensing, GIS, and NDVI analysis were used in research to estimate stored carbon stocks in Jatigede District, Sumedang Regency. These methods can improve the accuracy and efficiency of carbon stock estimates by providing preliminary data on the role that tree stands possess in absorbing carbon in the atmosphere. The purpose of this study was to ascertain the potential for carbon storage in mixed plantation tree stands as well as the amount of carbon stored in each village within Sumedang Regency's Jatigede District. The Normalized Difference Vegetation Index (NDVI), a geographic information system, and non-destructive sampling were the quantitative methods used in the research. The research's findings indicated that the estimated carbon stock in Jatigede District, Sumedang Regency, are 55,680.17135 tons/ha. Of the 12 villages in Jatigede District, Karedok Village has the largest carbon stock, at 13,368.05 tons/ha, while Sukakersa Village has the smallest, at 156.90 tons/ha.

Impact of community-based forest restoration on stand structural attributes, aboveground biomass and carbon stock compared to state-managed forests in tropical ecosystems of Sri Lanka.

Estimation of plant community composition, aboveground biomass and carbon stock is crucial for understanding forest ecology, strengthening environmental management, and developing effective tools and policies for forest restoration. This study was conducted in nine different forest reserves in Sri Lanka from 2012 to 2018 to examine the impact of community-based forest restoration (CBFR) on stand structural attributes, aboveground biomass, and carbon stock compared to state-managed forests. In total, 180 plots (90 plots in community-managed restoration blocks (CMRBs) and 90 plots assigned to state-managed restoration blocks (SMRBs)) were sampled at the study site. To conduct an inventory of standing trees, circular plots with a radius of 12.6 m (equivalent to an area of 500 square meters) were established. The Shannon diversity index, Allometric equations and Difference in Differences (DID) estimation were used to assess the data. Our study provides evidence of the positive impact of the CBFR program on enriching trees diversity. Considering stand structural attributes of both blocks showed higher trees density in the smaller diameter at breast height (DBH) category, indicating growth in both CMRBs and SMRBs. The results showed that tree biomass and carbon density were disproportionally distributed across the nine different forest reserves. On average, tree biomass and carbon density were higher in SMRBs (79.97 Mg ha-1, 37.58 Mg C ha-1) compared to CMRBs (33.51 Mg ha-1, 15.74 Mg C ha-1). However, CMRBs in Madigala reserve represent the highest biomass (56.53 and 59.92 Mg ha-1) and carbon density (26.57 and 28.16 Mg C ha-1). The results of biomass and carbon estimates were higher in all SMRBs in the nine different forest reserves compared to CMRBs. The findings suggest that future forest restoration programs in Sri Lanka should enhance participatory approaches to optimize tree species diversity, density and carbon storage, particularly in community-controlled forests. Our findings could assist developing tropical nations in understanding how CBFR impacts forest restoration objectives and improves the provision of ecological services within forests.

Estimation of carbon stocks in mangrove sediments in Ruyung Village, Mesjid Raya District, Aceh Besar Regency

Exploration related to blue carbon has increased recently. As one of the blue carbon ecosystems, the mangrove ecosystem is one of the coastal ecosystems that can absorb and store carbon. This research aims to calculate mangrove density and estimate carbon stocks in sediments in the mangrove ecosystem in Ruyung Village, Mesjid Raya District, Aceh Besar Regency. Mangrove density was calculated at three stations within 10 x 10 m transects. Sediment samples were also taken compositely, and carbon analysis was carried out in the sediment using the LOI (loss on ignition) method. There were two species of mangroves found at the research location, namely Rhizophora apiculata and Avicennia officionalis. The research results show that the average mangrove density at the research location is 0.20 ind/m2. The average soil density and sediment carbon stock at all research stations is 1.24 g/cm3 and 271.66 MgC/ha respectively. The mangrove ecosystem, both biomass and surrounding sediment, can store carbon, which is one of the ways to mitigate global warming.

Estimation of seagrass blue carbon stocks in Ahmad Rhang Manyang and Ujung Pancu Waters, Aceh Besar District

The blue carbon was concepted by the United Nations Environment Program (UNEP) in 2009, refers to the ability of marine and coastal ecosystems such as mangrove, seagrass, and tidal marshes to capture and store carbon dioxide through photosynthesis. This study aims to analyze the estimation of seagrass blue carbon stock and sequestration in Ahmad Rhang Manyang and Ujung Pancu. Data were collected using the plot transect method to assess cover, density, biomass and use model calculations called Seagrass Carbon Converter (SCC) to assess seagrass carbon stocks. Three species of seagrass were found at four research stations are Halodule pinifolia, Halophila ovalis, Halophila minor. The result showed that seagrass cover in Ahmad Rhang Manyang waters was 27.95% in the poor category and in Ujung Pancu waters was 39.4% in the medium category.. The seagrass carbon stock in Ahmad Rhang Manyang 123.93 gram C/m2 and in Ujung Pancu was 231.43 gram C/m2. The seagrass carbon absorption value in Ahmad Rhang Manyang was 4.16 TC/Ha/year (tons of carbon per hectare per year) and Ujung Pancu is 15.5 TC/Ha/year.

Economic valuation of selected ecosystem services in Islamabad Capital Territory (ICT), Pakistan.

Payment for ecosystem services (PES) is a mechanism where a consumer is able and ready to pay for the protection of the precise ecosystem service and there must be a provider such as local societies receiving an economic resource, who in return, must have the ability to maintain that ecosystem service. Economic valuation provides basis for payment for ecosystem services. Therefore, objective of this study was to evaluate tourism and carbon stock services of the Islamabad Capital Territory (ICT), Pakistan. Two forest zones (Chirpine and Scrub) of Islamabad capital territory (ICT) were selected for estimation of carbon stock and their carbon credits and carbon worth, a questionnaire-based survey was conducted for tourism as a payment for ecosystem services. The method for carbon stock assessment was systematic sampling for Chirpine forest whereas random sampling was done for scrub forest. The size of sampling plot was 17.84 m radius, and a total of 93 plots (49 Scrub zone and 44 Chirpine zone) was taken in the study area. The carbon stock of both zones (Chirpine and Scrub zone) is 22556.75 ton/ha (Chirpine 20105.79, Scrub 2450.96) and total carbon dioxide sequestered by both zone is 82557.72 ton/ha (Chirpine 73587.2, Scrub 8970.52), total carbon credits of both zone is 302160.87 (Chirpine 269328.97, Scrub 32831.9) and the carbon worth of both Chirpine and scrub zone is 4532418.92 $ (Chirpine 4039937.09$, Scrub 492481.83$). Similarly, from tourism point of view, in Shakar Parian, 94% tourists were agreed for PES whereas 6% were disagreed for the PES (the 6% tourist were disagreed to contribute for PES, 40% were agreed for Rs.5 contribution and 54% for Rs.10.). moreover, in Lake view Park, 97% tourists were agreed and 3% are disagreed (In Lake View Park 5% tourists were disagreed for the PES contribution whereas 32% were agreed for Rs.5 and 63% were for Rs.10). In Damen e Koh, around 87% tourist were agreed and 13% were disagreed, (24% were agreed for the contribution of Rs.5 and 63% tourists were agreed for the contribution of Rs.10). In Marghazar Zoo, 93% tourists were agreed (22% were agreed for contribution of Rs.5 and 71% tourist were agreed for contribution of Rs.10) and 7% are disagreed for PES whereas 7% tourists were not agreed for contribution. PES may implement to compensate forest and parks manager to ensure better management of the forests and parks. Due to prime location and scenic beauty of the ICT, it has huge potential for implementation of PES mechanism for sustainable forest management and conservation. Therefore, it is recommended that Capital Development Authority (CDA) Islamabad should devise a plan for implementation of PES in forests and parks of ICT for its sustainable management of recreational and forest resources.

Estimation of carbon stocks in ground cover in the oak, pine forests

Estimation of carbon stocks in ground cover in the oak, pine forests

Yield, carbon stock, and price dynamics of agroforestry tree species in district Mardan, Khyber Pakhtunkhwa, Pakistan.

A socio-economic study was conducted in district Mardan of the Khyber Pakhtunkhwa (KP) province of Pakistan to get a comprehensive knowledge of the agroforestry tree species grown on the farmlands, their yield, and carbon stock. For yield and carbon stock estimation, data were collected from 59 sample plots by measuring the diameter, height, volume, and biomass of selected agroforestry tree species through D-tape and Haga altimeter. A total of 59 sample plots were inventoried using 2.5 percent sampling intensity. Each sample plot has an area of 0.5 ha, where each tree with a Diameter at Breast Height (DBH) ≥ 5 cm was inventoried. The calculated amount of volume of each tree species was then converted to biomass by multiplying it by the density of wood and the Biomass Expansion Factor (BEF). Total yield and C stock for the selected agroforestry tree species were 11535.2 metric tons and 2102.2 metric tons, respectively. Populus euroamericana is classified as the main tree with 28% growing stock prior to Morus alba by 21%, while Melia azedarach, Eucalyptus camaldulensis, Dalbergia sissoo, Acacia nilotica, Salix tetrasperma, and Bombax ceiba consist of 15%, 12%, 8%, 6%,7% and 3% growing stock respectively. Among the species found in different sampling plots the yield of Populus euroamericana was found to be 4747.5 metric tons and it was followed by the species Morus alba found at 2027.3 metric tons. Similarly, the volume for Melia azedarach, Eucalyptus camaldulensis, Dalbergia sissoo, Salix spp, Boombox ceiba, and Acacia nilotica was 1532.2 tons,1503 ton,745.7,203.5ton, 555.4ton and 220.5ton, respectively. The carbon stock for Populus euroamericana was calculated as 777.8 ton/ha, while for Eucalyptus camaldulensis, Melia azedarach, Morus alba, Dalbergia sissoo, Acacia nilotica, Salix species, and Bombax ceiba it was calculated as 312.3ton/ha, 272.1ton/ha, 363ton/ha, 245.1ton/ha, 51.4ton/ha, 27.3ton/ha and 53.2ton/ha, respectively. The questionnaire survey conducted for price dynamics showed that the majority of respondents purchase timber from the market for construction. But they use farm trees with low-quality city construction. They dislike using local timber in the conventional building as timber from farm trees is liable to insect attack. Rs. 50,000-100000, (33.33%) of daily sales was concluded from 50% of the trader while (16.7%) of the traders have their sales between Rs.150,000-200,000. Therefore, it is concluded by the authors that both provincial and federal government should promote agroforestry in Pakistan through different incentives because it has the potential to cope with dilemma of deforestation of natural forests and improve the livelihood of local peoples. It is strongly recommended that special projects just like the Ten Billion Tree Afforestation Project (T-BTTP) should be launched for agroforestry plantation and promotion in the country to sustain the ecological harmony and uplift the socio-economic condition of the peoples of Pakistan.

Evaluation of Forest Stock Estimation Ability of High Resolution Airborne Multi-band PolSAR in Cold Temperate Coniferous Forests

Evaluation of Forest Stock Estimation Ability of High Resolution Airborne Multi-band PolSAR in Cold Temperate Coniferous Forests

Modeling Height–Diameter Allometric Relationships of Dominant African Oak (Afzelia africana Sm) From West African Dry Savannas

Tree height is an important ecological parameter for assessing biomass carbon accumulation rate and understanding the ontogenetic development of vascular plants. Given the lack of height measurement data, height–diameter allometric models are needed to improve carbon stock estimates. In this study, we investigated height–diameter relationships of dominant Afzelia africana Sm in West Africa. Using field measurements of 1483 trees across four forest sites and two climatic zones in Burkina Faso, we (i) compared the performance of 10 theoretical models in predicting height–diameter relationships, (ii) tested for site effects on tree height–diameter allometric relationships, and (iii) evaluated the performance of existing regional height–diameter equation in predicting tree height. We found that the asymptotic Gompertz model better described height–diameter allometric relationships of the studied species in the study area. A significant variation of the Lorey’s mean height and the asymptotic maximum height was observed between forest sites, highlighting the variations of height–diameter allometric relationships with site conditions. Existing height–diameter equation developed for West Africa significantly underestimates tree height of A. africana at between 53.34% and 62.63%. The height–diameter allometric models developed in this study can be applied for carbon stock estimates in the semiarid zones of West Africa. Mixed‐species height–diameter models integrating other sites and varying climatic conditions can improve biomass estimates and contribute to a better understanding of the drivers of height–diameter relationships in savannas.

Estimation of Carbon Stock in The Seagrass Meadows of Jelenga Bay, West Sumbawa, Indonesia

Blue carbon is a term used to describe the carbon stored in coastal and marine ecosystems. Research and conservation of blue carbon sinks like seagrass meadows are important in mitigating global climate change. This research aimed to estimate blue carbon stored in the seagrass meadows ecosystem of Jelenga Bay, West Sumbawa, Indonesia. Carbon stock in the seagrass community was estimated based on correlation analysis of density, biomass, and organic carbon content. Meanwhile, the correlation analysis of dry bulk density and organic carbon content was used to estimate the susbtrate carbon stock. Four seagrass species were found in Jelenga Bay, i.e., Enhalus acoroides, Thalassia hemprichii, Cymodocea rotundata, and Halodule pinifolia. Carbon stock estimation of the seagrass community within 107.1 hectares area showed that aboveground biomass stored 19.1 Mg of carbon (0.18 Mg C/ha), whereas belowground biomass stored 28.4 Mg of carbon (0.26 Mg C/ha). Carbon stock estimation in seagrass meadows substrate (in 1 meter depth) stored 4,590.0 Mg C (42.86 Mg C/ha). The substrate at 70-100 cm depth contributed the highest amount of carbon stock, i.e., 14.9 Mg. However, for the organic carbon content, depth of 1530 cm showed the highest result (0.341 % of Dry Bulk Density).

Hydroacoustic method and GIS-Dashboard visualization for fish size in Banggai Sea Waters

Estimating fish stocks, including their distribution and density, plays a vital role in the management of capture fisheries. Hydroacoustic technology is widely utilized for fish stock estimation study. In September 2022, BRIN and IPB University conducted hydroacoustic data measurement in the Banggai Sea as part of the “Banggai Upwelling Dynamics Exploration and Experiment” to estimate fish stocks. Very large fish (>58 cm) has a density of 12,452 fish km-2. The spatial distribution of fish occurs in the eastern waters of Banggai Island and the northern waters of Taliabu Island. The most significant potential is the epipelagic layer (0 to -200 meters), with very small-sized fish having the highest density, followed by large-sized and small-sized fish. To summarize the analysis results of fish density distribution , a GIS-Dashboard is utilized. This online platform integrates various maps and charts, offering an engaging and easily understandable visualization of the information.

Assessment of carbon sequestration of Teak (Tectona grandis Linn. F.) plantation on the campus of University of Ilorin, Nigeria

The study assessed the carbon sequestration of Tectona grandis Linn. F. in five age series (11-15 years old), at the University of Ilorin, north-central Nigeria. Data were collected using a stratified sampling technique and twenty square plots of 25 m × 25 m were laid. A non-destructive method was used to determine the biomass of the trees. Tree enumerations were carried out for diameters at the base, top, middle, diameter at breast height (DBH), and height. Soil samples at two different depths (0-15 cm and 15-30 cm) were collected and analyzed to obtain soil organic carbon. The results were summarized using descriptive statistics, while the relationship between tree growth variables and carbon stock was assessed using correlation and regression analysis. The results showed that tree carbon stocks were 230.05 t ha-1, 362.35 t ha-1, 277.48 t ha-1, 216.40 t ha-1, and 126.20 t ha-1 for 11 years old (2012), 12 years old (2011), 13 years old (2010), 14 years old (2009) and 15 years old (2008) age series, respectively. The soil organic carbon stocks were 1.1025 t ha-1, 0.6253 t ha-1, 1.2019 t ha-1, 1.4070 t ha-1 and 0.7615 t ha-1 for 11 years old (2012), 12 years old (2011), 13 years old (2010), 14 years old (2009) and 15 years old (2008) age series, respectively. The study also revealed that the 14-year-old (2009) age series had the highest carbon stock, and the total carbon stock estimate was 151,850.84 t. The potential cash value of the carbon stock was also estimated at $91,894.40 t C ha-1 and the total PCV was $56,606,951.50. Correlation analysis showed a strong positive correlation between most of the growth variables and carbon stock. The regression equation (Y = -596.48 + 27.16 THT + 1238.34 DBH, Adj R2 = 82.7%) showed that DBH and height of trees are suitable for evaluating the carbon stock in the study area.

Evaluating the impact of parametric pushover curve model uncertainties on seismic loss estimation for a specific building stock in Slovenia

Estimation of seismic loss at the community level is prone to uncertainty for various reasons. This paper addresses the introduced problem by performing a simple sensitivity study aimed at determining the most influential input parameters and models of the parametric pushover curve model on loss estimation of a building stock, provided that there is a low level of knowledge about the buildings. This sensitivity study was performed for a specific, critical building stock infrastructure in Slovenia by varying nine input parameters and the outcome of six models affecting the parametric pushover curves of the building stock. The expected annual loss and fatalities were used as the output parameters. Results showed that loss estimation was most sensitive to variation of the model for the determination of the fundamental period, followed by the models for the estimation of displacement at the near-collapse (NC) limit state, storey-drift uniformity coefficient, and the storey-drift angle at the NC limit state. However, loss estimation, particularly for the entire building stock, was less sensitive to models that influence the maximum base shear and related parameters. Nevertheless, the model of minimum base shear at the yield point for masonry buildings constructed after 1963 and the model of design base shear coefficient for reinforced concrete buildings built after 2007 should be defined more accurately than for other building categories. Given that these results are based on the parametric pushover curve model developed for Slovenia, they may not apply to all regions or different types of construction.