scholarly journals Quantifying the Relationship among Impact Factors of Shrub Layer Diversity in Chinese Pine Plantation Forest Ecosystems

Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 781 ◽  
Author(s):  
Boheng Wang ◽  
Yuankun Bu ◽  
Yanjie Li ◽  
Weizhong Li ◽  
Pengxiang Zhao ◽  
...  
Keyword(s):  
Soil Properties ◽  
Latent Variable ◽  
Path Coefficient ◽  
Site Conditions ◽  
Pine Plantation ◽  
Plantation Forest ◽  
Minimal Impact ◽  
Chinese Pine ◽  
Shrub Layer ◽  
Effective Factor

Shrub layer diversity is an essential component of the forest ecosystem diversity, that contributes significantly to structuring the community and maintaining diversity, especially in plantation forests. In previous studies, researchers have reported the strong relationship among various factors (i.e., soil composition, mean annual temperature, etc.) and shrub diversity. However, how these factors jointly influence shrub diversity and which factors could be considered the key factors is still unknown. In this study, we attempted to quantify the effect among environmental factors, soil factors and forest stand factors on shrub diversity. Twenty-seven variables were selected from 57 Chinese pine plantation plots in Huanglong Mountain, Yanan City, Shaanxi Province, China. The path models showed that latent variable of soil properties is the main effective factor of latent variable of shrub diversity (directly effect, path coefficient = 0.344) and the latent variable of site conditions is another effective factor of latent variable of shrub diversity (indirectly effect, path coefficient = 0.177); Besides, the latent variable of site conditions and forest properties directly affect the latent variable of soil properties (path coefficient = 0.514 and 0.326, respectively). Among the latent variable of soil properties, soil water content (SWC) has the biggest weight of 0.666, which indicated the most significant contribution of SWC to latent variables of shrub diversity. Total nitrogen, weighted 0.375, and total phosphorus, weighted 0.308, are also important factors and make a similar contribution to latent variable of shrub diversity. Soil organic matter (SOM) has a minimal impact (lowest weight, 0.059); among the objective variables of site condition, altitude contributes the most and is followed by litter thickness, weighted at 0.722 and 0.448, respectively. Furthermore, among all the variables affecting the latent variable of forest properties, forest age is recognized as the maximum impactor of soil property change, which weighted −0.941; and is followed by forest stock volume and diameter at breast height (DBH), weighted 0.795 and 0.788, respectively. The crowding index (C) has the lowest weight (−0.235) and demonstrated that spatial distribution and crowding of trees have minimal impact on the latent variable of Soil properties. diversity Overall, our study provides new insights into quantifying the relationships among different driving factors that potentially play a significant role in determining shrub layer diversity within the plantation forest.

scholarly journals Agents Affecting the Productivity of Pine Plantations on the Loess Plateau in China: A Study Based on Structural Equation Modeling

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1328
Author(s):  
Xuan Zhao ◽  
Yanjie Li ◽  
Hao Song ◽  
Yuhuan Jia ◽  
Jianjun Liu
Keyword(s):  
Indirect Effect ◽  
Latent Variables ◽  
Latent Variable ◽  
Structural Equation ◽  
Equation Modeling ◽  
Path Coefficient ◽  
Site Conditions ◽  
Population Stability ◽  
Forest Density ◽  
Weight Value

Stability and productivity are important indicators used to measure the state of forest ecosystems. Artificial forests populations with reasonable structures and strong stability are critical for ecosystem productivity. Previous studies have focused on individual factors, while the mechanisms of how multiple factors affect population productivity remain unknown. We used 57 plots in a Chinese pine (Pinus tabuliformis) plantation to investigate 23 stand factors and analyzed the relationships among site factors, population structure, population stability, and population productivity using partial least square-structural equation modeling (PLS-SEM). The results showed that the population productivity of the plantation was directly affected by the population stability latent variable but indirectly affected by the site conditions latent variables (indirect effect path coefficient = 0.249) and forest structure (indirect effect path coefficient = 0.222). However, the site conditions latent variable was the main factor directly affecting the population stability latent variables; the total effect was 0.511 (direct effect path coefficient = 0.307, indirect effect path coefficient = 0.204), and the influence of forest structure on population stability was lower than that of the site conditions latent variable (direct effect path coefficient = 0.454). The factor with the greatest weight among the site conditions latent variable was slope (0.747), indicating that slope contributes the most to latent variables related to forest population stability. Among all variables affecting the forest stability latent variables, forest density had the highest weight value (0.803), and the weight value of forest mortality was lower than that of forest density. The weights of the latent variables associated with population structure from high to low were canopy density, the uniform angle index, and the spatial competition index, indicating that competition for space had the lowest influence on the population stability latent variables. The results provide new insights and ideas for quantifying relationships among different driving factors and a basis for scientific and rational plantation management.

scholarly journals Effects of land cover type on carabid beetles (Coleoptera: Carabidae) of the Canterbury foothills, New Zealand

2019 ◽  
Vol 49 ◽  
Author(s):  
Lisa A. Berndt ◽  
Eckehard G. Brockerhoff
Keyword(s):  
New Zealand ◽  
Land Cover ◽  
Natural Forest ◽  
Carabid Beetle ◽  
Carabid Beetles ◽  
Native Forest ◽  
Potential Contribution ◽  
Pine Plantation ◽  
Plantation Forest ◽  
Beetle Assemblages

Background: Land cover changes during the recent history of New Zealand have had a major impact on its largely endemic and iconic biodiversity. As in many other countries, large areas of native forest have been replaced by other land cover and are now in exotic pasture grassland or plantation forest. Ground beetles (Carabidae) are often used as ecological indicators, they provide ecosystem services such as pest control, and some species are endangered. However, few studies in New Zealand have assessed the habitat value for carabid beetles of natural forest, managed regenerating natural forest, pine plantation forest and pasture. Methods: We compared the carabid beetle assemblages of natural forest of Nothofagus solandri var solandri (also known as Fuscospora solandri or black beech), regenerating N. solandri forest managed for timber production, exotic pine plantation forest and exotic pasture, using pitfall traps. The study was conducted at Woodside Forest in the foothills of the Southern Alps, North Canterbury, New Zealand, close to an area where the critically endangered carabid Holcaspis brevicula was found. Results: A total of 1192 carabid individuals from 23 species were caught during the study. All but two species were native to New Zealand, with the exotic species present only in low numbers and one of these only in the pasture habitat. Carabid relative abundance and the number of species was highest in the pine plantation, where a total of 15 species were caught; however, rarefied species richness did not differ significantly between habitats. The sampled carabid beetle assemblages were similar across the three forested habitat types but differed significantly from the pasture assemblages based on unconstrained and canonical analyses of principal coordinates. Holcaspis brevicula was not detected in this area. Conclusions: Our results show that managed or exotic habitats may provide habitat to species-rich carabid assemblages although some native species occur only in natural, undisturbed vegetation. Nevertheless, it is important to acknowledge the potential contribution of these land uses and land cover types to the conservation of native biodiversity and to consider how these can be managed to maximise conservation opportunities.

scholarly journals Effect of Soil Layer and Plant–Soil Interaction on Soil Microbial Diversity and Function after Canopy Gap Disturbance

Forests ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 680 ◽  
Author(s):  
Xuan Yu ◽  
Lin Yang ◽  
Shixuan Fei ◽  
Zitong Ma ◽  
Ruqian Hao ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Enzyme Activities ◽  
Soil Layer ◽  
Soil Microbial Communities ◽  
Gap Size ◽  
Pine Plantation ◽  
Soil Microbial Diversity ◽  
Chinese Pine ◽  
Soil Microbial ◽  
Microbial Plfas

Gaps by thinning can have different microclimatic environments compared to surrounding areas, depending on the size of the gap. In addition, gaps can play important roles in biological dynamics, nutrient cycling, and seedling regeneration. The impacts of gap size on soil microbial communities and enzyme activities in different soil layers in Chinese pine plantations are not well understood. Here, we created gaps of 45 m2 (small, G1), 100 m2 (medium, G2), and 190 m2 (large, G3) by thinning unhealthy trees in an aged (i.e., 50 years old) monoculture Chinese pine plantation in 2010. Soil samples were collected in 2015. The total, bacterial, Gram-positive (G+), and Gram-negative (G−) phospholipid fatty acid (PLFA) profiles were highest in medium gaps in both the organic and mineral layers. These indicesdecreased sharply as gap size increased to 190 m2, and each of the detected enzyme activities demonstrated the same trend. Under all the gap size managements, abundances of microbial PLFAs and enzyme activities in the organic layers were higher than in the mineral layers. The soil layer was found to have a stronger influence on soil microbial communities than gap size. Redundancy analysis (RDA) based on the three systems with different gap sizes showed that undergrowth coverage, diversity, soil total nitrogen (TN), total organic carbon (TOC), and available phosphorus (AT) significantly affected soil microbial communities. Our findings highlighted that the effect of gap size on soil microenvironment is valuable information for assessing soil fertility. Medium gaps (i.e., 100 m2) have higher microbial PLFAs, enzyme activity, and soil nutrient availability. These medium gaps are considered favorable for soil microbial communities and fertility studied in a Chinese pine plantation managed on the Loess Plateau.

Multiscale spatial variation of the bark beetle Ips sexdentatus damage in a pine plantation forest (Landes de Gascogne, Southwestern France)

2009 ◽  
Vol 257 (7) ◽  
pp. 1551-1557 ◽  
Author(s):  
J.-P. Rossi ◽  
J.-C. Samalens ◽  
D. Guyon ◽  
I. van Halder ◽  
H. Jactel ◽  
...  
Keyword(s):  
Spatial Variation ◽  
Bark Beetle ◽  
Pine Plantation ◽  
Plantation Forest ◽  
Ips Sexdentatus

scholarly journals Using psychometric data from the stated preference (SP) experiments to search explanatory power for appropriateness of congestion charging policy

2016 ◽  
Vol 5 (3) ◽  
Author(s):  
Sofyan M. Saleh ◽  
Sugiarto Sugiarto ◽  
Cut Mutiawati ◽  
Renni Angraini ◽  
Muhammad Isya
Keyword(s):  
Latent Variables ◽  
Latent Variable ◽  
Structural Equation ◽  
Stated Preference ◽  
Explanatory Power ◽  
Path Coefficient ◽  
Annual Income ◽  
Positive Correlation ◽  
Psychological Determinants ◽  
Psychometric Data

Comprehensive stated preference (SP) experiment was conducted in Jakarta (a capital of Indonesia), where proposal for congestion charge (CC) has been considered as a way to reduce acute traffic congestion. With the government planning a CC scheme, public support is regarded as a prerequisite for its implementation. Therefore, a framework of structural equation model (SEM) is used to search explanatory power for the appropriateness of CC considering unobserved variable (latent variable) from psychometric data obtained from SP questionare.  Causal paths among psychological determinants and their strength are measured and analyzed along with proposal acceptability from a psychological perspective. The findings from analysis with a SEM approach shows that a number of psychological determinants provide an explanation for the acceptability of the proposed scheme. The findings from analysis with a SEM approach shows that a number of psychological determinants provide an explanation for the appropriateness of the proposed scheme. Latent variables representing the validity of the CC scheme, such as ACE, APC and REC appear to have a significant explanation. These emerge as psychological determinants contributing a positive correlation with enhancement of appropriateness CC policy. Empirical result further shows that males have positive scores for the latent variables of car dependency (CDC) and inhibition freedom of movement (IFM). Furthermore, the variable of annual income, it has a positive correlation with recognition of the effects of CC in mitigating congestion and environmental problems (REC), car dependency (CDC) and awareness of the problems of cars in society (APC). This means that respondents with higher incomes are more concerned with the problems manifested by motorization while, on the contrary, the path coefficient between annual income (AI) and car dependency (CDC) has a value of 0.270. This discloses an automobile dependency. These findings should provide insight that designing a more acceptable policy in respecting to the acceptance of public in large.

scholarly journals Faktor - Faktor yang Memengaruhi Perilaku Konsumen Produk Kosmetik Halal di Kota Bogor

2019 ◽  
Vol 9 (1) ◽  
pp. 59
Author(s):  
Stevia Septiani ◽  
Retno Indraswari
Keyword(s):  
Women Workers ◽  
Latent Variable ◽  
Structural Equation ◽  
Descriptive Analysis ◽  
Sem Analysis ◽  
Primary Data ◽  
Equation Modeling ◽  
Path Coefficient ◽  
Purchasing Decisions ◽  
Positive Effect

The halal cosmetics industry has a very potential trend both globally and nationally. In Indonesia, the halal cosmetics industry is one of the industries that contribute to the improvement of the Islamic economy. Along with the development of public knowledge about organic products that are environmentally friendly and do not contain animal ingredients, the demand of halal cosmetics products are increase.Unfortunately, the great potential of the halal industry cannot be used properly by local brand. This study aims to analyze some factors that related in halal purchasing decisions. The primary data collection in this study was carried out by purposive sampling method which is women workers. Data processing methods include descriptive analysis and Structural Equation Modeling (SEM) analysis with Partial Least Squares (PLS) approach. The results of SEM analysis shown that the Psychological latent variable has a direct positive effect to Purchasing, with a path coefficient of 0.603. Psychological aspects are a relevant factor in the halal cosmetic purchasing as halal using motifs could be reflect fulfillment an attractive confession as female workers.

scholarly journals Water Use by Chinese Pine Is Less Conservative but More Closely Regulated Than in Mongolian Scots Pine in a Plantation Forest, on Sandy Soil, in a Semi-Arid Climate

2021 ◽  
Vol 12 ◽  
Author(s):  
Hongzhong Dang ◽  
Xueli Zhang ◽  
Hui Han ◽  
Shuai Chen ◽  
Mingyang Li
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Scots Pine ◽  
Xylem Sap ◽  
Soil Layer ◽  
Northern China ◽  
Plantation Forest ◽  
Sap Flux Density ◽  
Chinese Pine ◽  
Dry Conditions

The diversity of plant water use patterns among species and ecosystems is a matter of widespread debate. In this study, Chinese pine (Pinus tabuliformis, CP) and Mongolian Scots pine (Pinus sylvestris var. mongolica, MP), which is co-exist in the shelterbelt plantations in the Horqin Sandyland in northern China, were chosen for comparison of water use traits by monitoring xylem sap flow alongside recordings of the associated environmental factors over four growing seasons. Continuous sap flux density measurements were converted into crown projected area transpiration intensity (Tr) and canopy stomatal conductance (Gs). The results indicated that MP showed a higher canopy transpiration intensity than in CP, with Tr daily means (±standard deviation) of 0.84 ± 0.36 and 0.79 ± 0.43 mm⋅d–1, respectively (p = 0.07). However, the inter-annual variability of daily Tr in MP was not significant, varying only approximately a 1.1-fold (p = 0.29), while inter-annual variation was significant for CP, with 1.24-fold variation (p < 0.01). In particular, the daily mean Tr value for CP was approximately 1.7-times higher than that of MP under favorable soil moisture conditions, with values for relative extractable soil water within the 0–1.0 m soil layer (REW) being above 0.4. However, as the soil dried out, the value of Tr for CP decreased more sharply, falling to only approximately 0.5-times the value for MP when REW fell to < 0.2. The stronger sensitivity of Tr and/or Gs to REW, together with the more sensitive response of Gs to VPD in CP, confirms that CP exhibits less conservation of soil water utilization but features a stronger ability to regulate water use. Compared with MP, CP can better adapt to the dry conditions associated with climate change.

Economic analysis of growth response from a pine plantation forest applied with biosolids

2004 ◽  
Vol 189 (1-3) ◽  
pp. 345-351 ◽  
Author(s):  
Mark O Kimberley ◽  
Hailong Wang ◽  
Peter J Wilks ◽  
Craig R Fisher ◽  
Gujja N Magesan
Keyword(s):  
Economic Analysis ◽  
Growth Response ◽  
Pine Plantation ◽  
Plantation Forest
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