Determination of the best canopy gap area on the basis of soil characteristics using the Analytical Hierarchy Process (AHP)

The assessment of canopy gap areas on the basis of soil characteristics in forest ecosystems could be one of benefit points for management of forests. This research was conducted in 20 ha areas of Experimental Forest Station of Tarbiat Modares University that is located in a temperate forest of Mazandaran province in the north of Iran. Twenty one canopy gaps with different areas were found in studied areas and classified as small (85.12 m2), medium (325.21 m2), large (512.11 m2) and very large (723.85 m 2) gaps. These areas classes of canopy gaps were assessed with respect to nine criteria (soil pH, carbon to nitrogen ratio, cation exchange capacity, phosphorus, potassium, calcium, nitrogen mineralization, microbial respiration and earthworm's biomass). Soil samples (0-45 cm depth from the gap center and edge positions) were measured in the laboratory. The Analytical Hierarchy Process (AHP) was used for assessment of canopy gap areas. This method is widely used the Multiple Criteria Decision Support (MCDS) method and perhaps the most popular in many fields, including natural resource management, especially in forest sciences. Results of AHP indicate that the maximum of local priority belongs to small areas of canopy gaps when considering all soil characteristics. However, medium, large and very large canopy gap areas have priorities, respectively. The calculated overall priority showed that with respect to considered criterias, small and medium gap areas have higher, more ideal condition in comparison to large and very large areas. AHP results emphasise that considering soil characteristics canopy gap areas should be less than 400 m2 in Hyrcanian forests of Iran. Also, AHP can be introduced as an effective instrument in decision-making processes for investment planning and prioritization in compliance with environmental regulations

Soil functional indicators in a mountain forest-rangeland mosaic of northern Iran

Abstract Soil plays an essential role in providing ecosystem services, especially in mountain ecosystems which are often considered as fragile and sensitive systems and commonly consist of a mosaic of forest and rangeland plant communities. The relationship between above-ground plant cover and the properties of soil organic and mineral layers in mountain areas are rarely studied. This research aimed to assess the effect of different land covers (i.e. forest, forest-rangeland ecotone, and rangeland) on soil functional indicators, i.e. fertility and biological activities, in the Hyrcanian region of northern Iran. We hypothesized that (i) the presence of tree cover enhances soil fertility and biological activities and creates hot spots (islands) of soil functional indicators especially in the topsoil, (ii) litter quality and organic matter fractions are the drivers for activities of soil organisms, nutrient cycles and transformation processes in mountain ecosystems. Litter (O-horizon including L, F and H layers) and mineral soil samples (in two separate depths of 0–10 cm and 10–20 cm) were taken using iron frames (30 × 30 cm). In total, 45 litter and 90 soil samples were transferred to the laboratory. Soil characteristic especially in the 0–10 cm depth, litter carbon (C), nitrogen (N) and C/N ratio were significantly affected by different land covers showing the maximum of soil organic C and microbial activity under forest. Our findings showed that the studied land covers, as well as litter and soil properties can be separated by PCA output. The first and second axes, accounted more than 50% of the explained variance in each of the studied soil depths. Soils with a better quality of litter (i.e. lower C/N ratio), higher values for organic matter fractions, soil fertility indicators and soil biological activities can be attributed to the forest. In contrast, positions of low soil fertility indicator values and biota abundance were imposed by forest-rangeland ecotone and rangeland. Although each land cover plays a prominent ecological role and takes its place in the evolutionary process, forests are essential because of their capacity to store and transform carbon and nutrients and to create hotspots identified by functional soil indicators. Based on our findings, soil functions decreased ranked in the order forest > forest-rangeland ecotone > rangeland, which can be assigned to the lower density of trees, and the amount of litter mass and litter quality. It can be concluded that tree covers have a prominent role in increasing soil functions, which should be given special consideration in the restoration of degraded mountain ecosystems

Impact of Land Cover Changes on Reducing Greenhouse Emissions: Site Selection, Baseline Modeling, and Strategic Environmental Assessment of REDD+ Projects

peer reviewedReducing emissions from deforestation and forest degradation (REDD+) is way key to reduce the emission of greenhouse gases (GHGs) while also protecting vulnerable forest ecosystems. The purpose of this study was to recognize suitable areas for REDD+ Programme projects and calculate the reduction in CO2 emissions through the prevention of forest cover degradation in the Central Hyrcanian forests. For this purpose, the cover changes of the Central Hyrcanian forests were assessed using LANDSAT satellite images. Applying the voluntary carbon standard (VCS) methodology and the calibration period 1984–2014 (30 years), forest cover changes were predicted. The results showed that under the business-as-usual scenario, 155,698 ha of Central Hyrcanian forests will be declined by 2044. In general, the REDD+ Programme project implementation will prevent the release of 1,209,231 tCO2e. Based on the social cost of carbon (SCC) approach, the REDD+ Programme project implementation can save 12,092,310 US$. In addition, this approach can be used for the project design document (PDD) of the forest development mechanism

Global data on earthworm abundance, biomass, diversity and corresponding environmental properties

14 p.Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change

Global data on earthworm abundance, biomass, diversity and corresponding environmental properties

Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change

Global data on earthworm abundance, biomass, diversity and corresponding environmental properties

Publisher Copyright: © 2021, The Author(s).Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change.Peer reviewe

Application of Statistical Method of Path Analysis to Describe Soil Biological Indices

Introduction: Among the collection of natural resources in the world, soil is considered as one of the most important components of the environment. Protect and improve the properties of this precious resource, requires a comprehensive and coordinated action that only through a deep understanding of quantitative (not only recognition of the quality) the origin, distribution and functionality in a natural ecosystem is possible. Many researchers believe that due to the quick reactions of soil organisms to environmental changes, soil biological survey to estimate soil quality is more important than the chemical and physical properties. For this reason, in many studies the nitrogen mineralization and microbial respiration indices are regarded. The aim of the present study were to study the direct and indirect effects of soil physicochemical characteristics on the most important biological indicators (nitrogen mineralization and microbial respiration), which has not been carefully considered up to now. This research is the first study to provide evidence to the future planning and management of soil sciences. Materials and Methods: For this, a limitation of 20 ha area of Experimental Forest Station of Tarbiat Modares University was considered. Fifty five soil samples, from the top 15 cm of soil, were taken, from which bulk density, texture, organic C, total N, cation exchange capacity (CEC), nitrogen mineralization and microbial respiration were determined at the laboratory. The data stored in Excel as a database. To determine the relationship between biological indices and soil physicochemical characteristics, correlation analysis and factor analysis using principal component analysis (PCA) were employed. To investigate all direct and indirect relationships between biological indices and different soil characteristics, path analysis (path analysis) was used. Results and Discussion: Results showed significant positive relations between biological indices and clay, organic carbon and total nitrogen, whereas the correlations of the other soil properties (bulk density, silt, sand and CEC) were insignificant. Factor analysis using of principle component analysis showed that the behavior of these two biological indices in the same territory and controlled by the same factors. Path analysis was employed to study the relationship among soil biological indices and the other soil properties. According to results, soil nitrogen mineralization is more imposed by nitrogen (0.98) and organic carbon (0.91) properties as direct and indirect effects respectively. Whereas the values of soil microbial respiration were affected by organic carbon (0.89) and total nitrogen (0.81). It can be claimed that total nitrogen and organic carbon are the most important soil properties in relation to nitrogen mineralization and microbial respiration, respectively. Regarding to the strong relationship between soil organic carbon and nitrogen and also similarly strong relationship between nitrogen and organic carbon mineralization, enhancing nitrogen mineralization is expected by the increase in organic carbon. In this regard, Nourbakhsh, et al. (2002) claimed that nitrogen mineralization is depended to soil organic nitrogen and derived from total nitrogen. In addition, there is a strong relationship between total nitrogen and soil organic carbon. So, the greater amounts of nitrogen mineralization can be related to more accumulation of organic carbon and nitrogen in topsoil (23). This result is in accordance with Wood, et al. (1990) and Norton, et al. (2003) findings (21, 30). Ebrahimi, et al. (2005) stated that if the C/N ratio is more than 30, the process immobility or nitrogen mineralization stopwill be occurred. The ratios between 20 and 30 usually settle and release of mineral nitrogen does not take place, and the balance remains. If the C/N ratio is less than 20 net release of nitrogen in the soil will increase (9).In the present study, the values of soil C/N ratio were less than 20 (mean 15.80), so the process of nitrogen mineralization occurred in the study area. Suitable conditions for microbial activity of soil microorganism's especially adequate supply of organic carbon increased the microbial respiration in the study area. High correlation between the amount of organic carbon and microbial respiration confirmed this claim. However; it seems that the soil organic carbon is driver of microbial respiration rate. This finding is reported by different researchers (6, 7, 15, and 20). Conclusion: Path analysis as a complementary method of regression analysis and factor analysis using principal component analysis showed that the biological activity of the soil characteristics are directly affected by soil nitrogen (for nitrogen mineralization index) and organic carbon (for microbial respiration index) and other useful features influence them indirectly through strong correlation with the characteristics of nitrogen and organic carbon in soil