scholarly journals Species-specific determinants of mortality and recruitment in the forest-steppe ecotone of northeast China

2016 ◽  
Vol 92 (03) ◽  
pp. 336-344 ◽  
Author(s):  
Nan Zeng ◽  
Huaxia Yao ◽  
Mei Zhou ◽  
Pengwu Zhao ◽  
Jeffrey P. Dech ◽  
...  
Keyword(s):  
Tree Mortality ◽  
Linear Models ◽  
Chemical Properties ◽  
Average Diameter ◽  
Slope Position ◽  
Available Phosphorus ◽  
Forest Steppe ◽  
Soil Variables ◽  
Populus Davidiana ◽  
Species Specific

Tree mortality is a notable phenomenon in the forest-steppe ecotone of China. However, the association between mortality and factors such as a changing climate is uncertain. In the summer of 2014 tree mortality was investigated in 20 × 400 m2 plots to determine the species-specific determinants of mortality and their influence on subsequent species recruitment. Nine soil physical-chemical properties were examined in addition to slope position, mean DBH and total number of trees. Generalized linear models analyzed relationships between these variables and mortality and recruitment. Mortality was positively associated with increasing average diameter and negatively to high soil pH and total nitrogen content. Recruitment models indicate that Populus davidiana recruitment was positively affected by available phosphorus and mortality, and negatively related to mean DBH. Slope position was the most important contributing variable to Betula platyphylla recruitment. With Quercus mongolica recruitment, soil variables played an important role. These results suggest that tree mortality is affected by soil properties, topography and tree size in China's forest-steppe ecotone, and may improve our understanding of species mortality and contribute to improved forest management.

scholarly journals Effects of Graphene on Larix olgensis Seedlings and Soil Properties of Haplic Cambisols in Northeast China

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 258 ◽  
Author(s):  
Jinfeng Song ◽  
Kai Cao ◽  
Chengwei Duan ◽  
Na Luo ◽  
Xiaoyang Cui
Keyword(s):  
Northeast China ◽  
Chemical Properties ◽  
Average Diameter ◽  
Available Phosphorus ◽  
Larix Olgensis ◽  
Nitrogen And Phosphorus ◽  
Low Concentrations ◽  
Physiological Indexes ◽  
High Concentrations ◽  
Phosphorus And Potassium

We investigated the impacts of graphene application at different concentrations on the growth and physiological characteristics of Changbai larch (Larix olgensis A. Henry) seedlings and the chemical properties and enzyme activities of Haplic Cambisols under these seedlings. The aim is to evaluate the environmental effects of graphene on the afforestation species and the zonal forest soils of Northeast China. Seedlings receiving 0 (CK), 25, 50, 100, 250, or 500 mg L−1 graphene were incubated for 30, 40, or 50 days. Low concentrations (25–50 mg L−1) of graphene increased the dry masses of root, stem, and leaf; however, high concentrations (100–500 mg L−1) inhibited them. Compared with those under 0 mg L−1 graphene, the root length, surface area, volume, and average diameter all increased during the early stages of incubation (i.e., 30 and 40 days) under low concentration of graphene (<50 or 100 mg L−1) and decreased at higher graphene concentration (>100 mg L−1); at 50 days, they were significantly inhibited. At 30 days, graphene decreased superoxide dismutase (SOD) and peroxidase (POD) activities, as well as pigment, soluble protein, and proline contents, and the decline increased with increasing graphene concentration; at 40 and 50 days, the above parameters increased initially and then decreased, reaching a maximum at 50 mg L−1. The changes in relative conductivity and malondialdehyde (MDA), superoxide anion and hydrogen peroxide contents were the opposite of those in the physiological indexes mentioned above. Therefore, graphene caused different degrees of oxidative stress in L. olgensis seedlings. At 30 days, graphene generally increased the organic matter, hydrolytic nitrogen, and available phosphorus and potassium contents of Haplic Cambisols, but these parameters decreased at 40 and 50 days. Graphene generally decreased acid phosphatase, urease, dehydrogenase, and catalase activities. Therefore, when graphene reaches a certain content level in this soil, it may also affect nitrogen and phosphorus cycling.

scholarly journals Effect of sprinkler irrigation on the properties of leached chernozem and the yield of Bromopsis inermis Leyss. in the Southern Cis-Ural

2021 ◽  
Author(s):  
Alexander Komissarov ◽  
Mikhail Komissarov ◽  
Irek Minniakhmetov ◽  
Oleg Lykasov ◽  
Julia Afanasyeva
Keyword(s):  
Chemical Properties ◽  
Sprinkler Irrigation ◽  
Available Phosphorus ◽  
Forest Steppe ◽  
Rooting Zone ◽  
Leached Chernozem ◽  
Chernozem Soils ◽  
Aggregate Composition ◽  
And Chemical Properties

The paper examines the effect of the long-term (10 years) low-intensity sprinkler irrigation on the properties of leached chernozem soils covered with Bromopsis inermis Leyss. (BIL) stands in the Southern Cis-Ural forest-steppe. The study analysed changes in the soil’s agrophysical and chemical properties. As a result of long-term irrigation, the humus horizon (A + AB) thickness increased by 16 ± 3 cm; the organic carbon (Corg) content and nutrients decreased in this rooting zone, in particular, Corg by 0.3%, available phosphorus by 24.8 mg/kg, exchangeable potassium by 18.4 mg/kg and the stock of Corg by 16 t/ha. The particle size distribution of irrigated soil did not significantly changed; some changes were observed for the soil’s aggregate composition. The soil’s hydrophysical properties, water and air regime worsened.

scholarly journals Double-Crested Cormorant Disturbance: Restoration Potential for a Forested Urban Park

2021 ◽  
Author(s):  
Andrew Millward
Keyword(s):  
Urban Forestry ◽  
Chemical Properties ◽  
Tree Cover ◽  
Systematic Sampling ◽  
Soil Variables ◽  
Multi Criteria Evaluation ◽  
Colonial Waterbirds ◽  
Restoration Potential ◽  
Point Data ◽  
Species Specific

This paper examines the relationship between double-crested cormorant nesting activity and urban deforestation in Toronto’s Tommy Thompson Park (TTP). TTP is located on a human constructed spit, providing habitat for colonial waterbirds to nest along Lake Ontario’s shoreline. In recent decades, double-crested cormorant colonization has resulted in the deforestation of the western edge of the park. This deforestation is causing a steady retreat of tree cover, where newly exposed soils are vulnerable to colonization by invasive plants and erosive wind and wave action. Following a 30x30 m systematic sampling approach, geospatial interpolation of point data describing current soil physical and chemical properties is used to create continuous soil prediction surfaces. Interpolated surfaces are then combined to create site suitability maps using multicriteria evaluation (MCE) to weight the soil variables, and to provide a ranked output of desirable site locations for species-specific re-vegetation potential. Keywords: double-crested cormorant, urban forestry, restoration, kriging, multi-criteria evaluation

scholarly journals Double-Crested Cormorant Disturbance: Restoration Potential for a Forested Urban Park

2021 ◽  
Author(s):  
Andrew Millward
Keyword(s):  
Urban Forestry ◽  
Chemical Properties ◽  
Tree Cover ◽  
Systematic Sampling ◽  
Soil Variables ◽  
Multi Criteria Evaluation ◽  
Colonial Waterbirds ◽  
Restoration Potential ◽  
Point Data ◽  
Species Specific

This paper examines the relationship between double-crested cormorant nesting activity and urban deforestation in Toronto’s Tommy Thompson Park (TTP). TTP is located on a human constructed spit, providing habitat for colonial waterbirds to nest along Lake Ontario’s shoreline. In recent decades, double-crested cormorant colonization has resulted in the deforestation of the western edge of the park. This deforestation is causing a steady retreat of tree cover, where newly exposed soils are vulnerable to colonization by invasive plants and erosive wind and wave action. Following a 30x30 m systematic sampling approach, geospatial interpolation of point data describing current soil physical and chemical properties is used to create continuous soil prediction surfaces. Interpolated surfaces are then combined to create site suitability maps using multicriteria evaluation (MCE) to weight the soil variables, and to provide a ranked output of desirable site locations for species-specific re-vegetation potential. Keywords: double-crested cormorant, urban forestry, restoration, kriging, multi-criteria evaluation

scholarly journals A large database supports the use of simple models of post-fire tree mortality for thick-barked conifers, with less support for other species

Fire Ecology ◽  
2020 ◽  
Vol 16 (1) ◽  
Author(s):  
C. Alina Cansler ◽  
Sharon M. Hood ◽  
Phillip J. van Mantgem ◽  
J. Morgan Varner
Keyword(s):  
Tree Mortality ◽  
Characteristic Curve ◽  
Small Diameter ◽  
Fire Effects ◽  
Tree Level ◽  
Clear Understanding ◽  
Bark Thickness ◽  
Mortality Models ◽  
Species Specific ◽  
Stem Mortality

Abstract Background Predictive models of post-fire tree and stem mortality are vital for management planning and understanding fire effects. Post-fire tree and stem mortality have been traditionally modeled as a simple empirical function of tree defenses (e.g., bark thickness) and fire injury (e.g., crown scorch). We used the Fire and Tree Mortality database (FTM)—which includes observations of tree mortality in obligate seeders and stem mortality in basal resprouting species from across the USA—to evaluate the accuracy of post-fire mortality models used in the First Order Fire Effects Model (FOFEM) software system. The basic model in FOFEM, the Ryan and Amman (R-A) model, uses bark thickness and percentage of crown volume scorched to predict post-fire mortality and can be applied to any species for which bark thickness can be calculated (184 species-level coefficients are included in the program). FOFEM (v6.7) also includes 38 species-specific tree mortality models (26 for gymnosperms, 12 for angiosperms), with unique predictors and coefficients. We assessed accuracy of the R-A model for 44 tree species and accuracy of 24 species-specific models for 13 species, using data from 93 438 tree-level observations and 351 fires that occurred from 1981 to 2016. Results For each model, we calculated performance statistics and provided an assessment of the representativeness of the evaluation data. We identified probability thresholds for which the model performed best, and the best thresholds with either ≥80% sensitivity or specificity. Of the 68 models evaluated, 43 had Area Under the Receiver Operating Characteristic Curve (AUC) values ≥0.80, indicating excellent performance, and 14 had AUCs <0.7, indicating poor performance. The R-A model often over-predicted mortality for angiosperms; 5 of 11 angiosperms had AUCs <0.7. For conifers, R-A over-predicted mortality for thin-barked species and for small diameter trees. The species-specific models had significantly higher AUCs than the R-A models for 10 of the 22 models, and five additional species-specific models had more balanced errors than R-A models, even though their AUCs were not significantly different or were significantly lower. Conclusions Approximately 75% of models tested had acceptable, excellent, or outstanding predictive ability. The models that performed poorly were primarily models predicting stem mortality of angiosperms or tree mortality of thin-barked conifers. This suggests that different approaches—such as different model forms, better estimates of bark thickness, and additional predictors—may be warranted for these taxa. Future data collection and research should target the geographical and taxonomic data gaps and poorly performing models identified in this study. Our evaluation of post-fire tree mortality models is the most comprehensive effort to date and allows users to have a clear understanding of the expected accuracy in predicting tree death from fire for 44 species.

scholarly journals Effect of Tillage System and Organic Matter Management Interactions on Soil Chemical Properties and Biological Activity in a Spring Wheat Short-Time Cultivation

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7451
Author(s):  
Barbara Breza-Boruta ◽  
Karol Kotwica ◽  
Justyna Bauza-Kaszewska
Keyword(s):  
Organic Matter ◽  
Biological Activity ◽  
Organic Carbon ◽  
Spring Wheat ◽  
Chemical Properties ◽  
Soil Samples ◽  
Available Phosphorus ◽  
Organic Carbon Content ◽  
Tillage System ◽  
Short Time

Properly selected tillage methods and management of the available organic matter resources are considered important measures to enable farming in accordance with the principles of sustainable agriculture. Depending on the depth and intensity of cultivation, tillage practices affect soil chemical composition, structure and biological activity. The three-year experiment was performed on the soil under spring wheat (cv. Tybalt) short-time cultivation. The influence of different tillage systems and stubble management on the soil’s chemical and biological parameters was analyzed. Organic carbon content (OC); content of biologically available phosphorus (Pa), potassium (Ka), and magnesium (Mg); content of total nitrogen (TN), mineral nitrogen forms: N-NO3 and N-NH4 were determined in various soil samples. Moreover, the total number of microorganisms (TNM), bacteria (B), actinobacteria (A), fungi (F); soil respiratory activity (SR); and pH in 1 M KCl (pH) were also investigated. The results show that organic matter amendment is of greater influence on soil characteristics than the tillage system applied. Manure application, as well as leaving the straw in the field, resulted in higher amounts of organic carbon and biologically available potassium. A significant increase in the number of soil microorganisms was also observed in soil samples from the experimental plots including this procedure.

scholarly journals Adsorption of Copper in Soil and its Dependence on Physical and Chemical Properties

2018 ◽  
Vol 66 (1) ◽  
pp. 219-224 ◽  
Author(s):  
Vítězslav Vlček ◽  
Miroslav Pohanka
Keyword(s):  
Soil Properties ◽  
Solid Phase ◽  
Chemical Properties ◽  
Total Content ◽  
Exchange Capacity ◽  
Soil Reaction ◽  
Available Phosphorus ◽  
Copper Adsorption ◽  
Phosphorus And Potassium ◽  
Physical And Chemical

Soil samples (n = 11) were collected in the chernozem areas of the Czech Republic (the Central Europe) from the topsoil and used as representative samples. All sampling areas have been used for agricultural purposes (arable soil) and they were selected as typical representatives of agricultural soil. These samples represented the soil with same genesis (to reduction differencies between soil types) but with different soil properties (physical and chemical). Complete chemical and physical analyses were made for confirmation of copper adsorption on solid phase: we analysed the particle size distribution, content of oxidizable carbon (Cox), the cation exchange capacity (CEC), supply of exchange calcium, magnesium, sodium, phosphorus and potassium, soil reaction and the total supply of Fe, Al, Mn, Ca, Mg, K, P and N. The strongest simple correlation between analysed soil properties and copper concentration had content of available magnesium (r = 0.44) and available phosphorus (r = −0.51). In the case of multiple correlations (i. e. collective influence of multiple soil properties) had the strongest influence combination of clay, soil reaction, total content of phosphorus, available magnesium and available phosphorus. The main influence of phosphorus and magnesium is evident. We suppose that copper and phosphorus enter into specific complex. Influence of these five soil properties can explain 92.7 % (r = 0.927) changes in the content of copper changes in the experiment.

scholarly journals Features of Waste Chemical Processing Germanium Concentrates

2020 ◽  
Author(s):  
Igor Nikolaevich Tanutrov ◽  
Marina Nikolaevna Sviridova
Keyword(s):  
Chemical Properties ◽  
Average Diameter ◽  
Toxic Waste ◽  
High Temperature Treatment ◽  
High Dispersion ◽  
Chemical Processing ◽  
Particle Sizes ◽  
Physical And Chemical Properties ◽  
Physical And Chemical ◽  
And Chemical Properties

In order to increase the extraction of germanium in the technology of production of germanium concentrates, as well as finding ways to eliminate the accumulation of toxic waste using modern techniques and equipment, the physical and chemical properties of waste chemical processing of germanium concentrates (OHGC) of two domestic enterprises were experimentally studied. The main components of OHGC are: sulphate hemihydrate CaSO4·0.5H2O and hypochlorite Ca(OCl)2 calcium. The moisture content of the sludge amounted to 30–50 %. The content of germanium in the cakes of both companies is in the range of 0.20 and 0.27 %, respectively, indicating the feasibility of recovery in the Ge. At the same time, the samples of cakes differ significantly in the content of impurities, which depends on the types of raw materials in the preparation of concentrates. Granulometric composition of cakes is characterized by high dispersion. With an average diameter of 12 μm, all particle sizes are in the range of 0.5-15 μm. The distribution of particle sizes is shifted in interval of 0–15 μm, and the area of the particles less than 3 μm is not more than 10 %. The high dispersion of the cake is reflected in the specific surface area, which is 23.7 m2/g. Thermographic study found that the heating of the sample cake is accompanied by two endothermic effects of dehydration at 110 and 145–168 ∘C calcium sulfate and hypochloride semihydrate with corresponding weight loss of 13.1 and 12.9 %. The presence of toxic impurities (arsenic, zinc and lead), as well as chlorine, presents significant challenges for the development of disposal technology with the extraction of germanium. Assuming that the undiscovered part of the germanium in the concentrate is compounds or solid solutions with silicon dioxide, an effective technology should include their reagent high temperature treatment. Keywords: waste, germanium concentrate, chemical processing, waste, physical and chemical properties

scholarly journals Liming Effects of Sawdust Ash and Lime on Sunflower (Helianthus annuus L.) Yield in Acidic Soil of Southeastern Nigeria

2019 ◽  
pp. 1-11
Author(s):  
C. V. Ogbenna ◽  
V. E. Osodeke
Keyword(s):  
Soil Ph ◽  
Chemical Properties ◽  
Exchange Capacity ◽  
Acidic Soil ◽  
Soil Chemical Properties ◽  
Growth And Yield ◽  
Available Phosphorus ◽  
Yield Data ◽  
Southeastern Nigeria ◽  
Head Weight

Aim: A pot experiment was carried out to determine the effect of sawdust ash and lime (Ca(OH)2) on soil characteristics and yield of sunflower in acidic soil of southeastern Nigeria. Study Design: The experiment was laid out in split-plot design, using sawdust ash (0, 1, 2, 3, 4 t ha-1) as the sub plot and lime (0, 0.5, 1.0, 1.5 t ha-1) as the main plot. Place and Duration of Study: Study was conducted outdoors at Michael Okpara University of Agriculture Umudike, Nigeria, during the 2010 planting season. Materials and Methods: Treatment combinations were applied to the 60 buckets containing soil, mixed thoroughly and watered adequately. After 1 week of treatment application, two sunflower seeds were planted and later thinned to one seedling per bucket. Plant growth and yield data were collected. Pre planting and post-harvest soil samples were collected and analyzed for soil properties. Results: Results showed that with the exception of organic carbon there was significant effect of treatments on all soil chemical properties. Lime and sawdust ash (SDA) as single and combined treatments significantly increased total nitrogen (P=0.05), available phosphorus (P<0.010), and base saturation (P<0.012). The interaction between SDA and lime significantly (P=0.05) increased total exchangeable bases and effective cation exchange capacity, while soil pH was significantly increased (P=0.05) by single applications. The increases in soil chemical properties led to significant positive response of the sunflower. With the exception of number of leaves, other plant parameters (Plant height, stem diameter, head weight, 50 seed weight, head diameter) had significant increases for sawdust ash alone at P=0.05. Correlation studies showed positive significant relationship between soil pH and sunflower yield. Conclusion: The study showed that sunflower performed best at the combination of 3 tha-1 SDA and 1.5 t ha-1 lime producing a mean head weight of 45.4 g.

scholarly journals Evaluation of Physicochemical Properties and Microbial Populations of Soil of Bagale Forest Reserve, Girei Local Government Area, Adamawa State, Nigeria

2020 ◽  
pp. 13-21
Author(s):  
G. O. Ateh ◽  
M. G. Saka ◽  
E. E. Dishan ◽  
B. B. Meer
Keyword(s):  
Local Government ◽  
Physicochemical Properties ◽  
Soil Depth ◽  
Chemical Properties ◽  
Soil Samples ◽  
Local Government Area ◽  
Microbial Populations ◽  
Available Phosphorus ◽  
High Porosity ◽  
Forest Reserve

This study evaluated the relationship between selected physicochemical properties and microbial populations of the soil of Bagale Forest Reserve, Girei Local Government Area of Adamawa State, Nigeria. Five plots of 20 x 20 m were laid. Soil samples were collected from five different positions at two soil depths of 0-15 cm and 15-30 cm. The soil samples were isolated in the laboratory for microbial populations and determination of physical and chemical properties. The results obtained revealed that fungal population (7.65 x 105 cfu/ml) was the highest at the soil depth of 0-15 cm, representing 39% of the total microbial populations in the sampled soil of the study area. The results further revealed that the population (6.84 x 105 cfu/ml) of the bacteria had a positive effect on soils of the study area in terms of nitrogen fixation by Rhizobacterial spp. Chemical properties of the soil samples revealed that the available phosphorus exhibited the highest percentage (61.7%) at 0-15 cm soil depth. Analyses of soil physical properties recorded the highest percentage (49.0%) of sand at 0-15 cm soil depth. A similar percentage (50.0%) of sand was exhibited at the depth of 15-30 cm. These percentages accounted for the high porosity (29.0%) of the soil observed at the two soil levels in the study area and could be improved through the application of lime fertilizers. Application of appropriate fertilizers like NPK to improve the soil condition of the study area is highly recommended.

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