scholarly journals A positive correlation between plant diversity and productivity is indirectly caused by environmental factors driving spatial pattern of vegetation composition in semiarid sandy grassland

2011 ◽  
Vol 8 (6) ◽  
pp. 11795-11825
Author(s):  
X. A. Zuo ◽  
J. M. H. Knops ◽  
X. Y. Zhao ◽  
H. L. Zhao ◽  
Y. Q. Li ◽  
...  

Abstract. Although patterns between plant diversity and ecosystem productivity have been much studied, a consistent relationship has not yet emerged. Several different patterns have been observed both naturally and experimentally, likely caused by spatial variability of environmental factors and vegetation composition. In this study, we measured the vegetation cover, plant diversity, productivity, soil properties and site characteristics along an environment gradient of natural sandy grasslands (mobile dune, semi-fixed dune, fixed dune, dry meadow, wet meadow and flood plain grassland) in a semiarid area of Northern China. We used multivariate analysis to examine the relationships between environment factors, vegetation composition, plant diversity and productivity. We found a positive correlation between plant diversity and productivity. Vegetation composition had also a significantly positive correlation with plant diversity and productivity. Environment gradients in relation to soil properties and topography features affected the distribution patterns of species diversity, vegetation composition and productivity. However, environment gradients are a better determiner for vegetation composition and productivity than for species diversity. The analysis from optimization model of structural equation suggests that environmental factors determine vegetation composition, which in turn drives independently both plant diversity and productivity. Thus the positive correlation between plant diversity and productivity is not direct, but indirectly driven by the spatial pattern of vegetation composition determined by environment gradients in soil and topography.

2012 ◽  
Vol 9 (4) ◽  
pp. 1277-1289 ◽  
Author(s):  
X. A. Zuo ◽  
J. M. H. Knops ◽  
X. Y. Zhao ◽  
H. L. Zhao ◽  
T. H. Zhang ◽  
...  

Abstract. Although patterns between plant diversity and ecosystem productivity have been much studied, a consistent relationship has not yet emerged. Differing patterns between plant diversity and productivity have been observed in response to spatial variability of environmental factors and vegetation composition. In this study, we measured vegetation cover, plant diversity, productivity, soil properties and site characteristics along an environmental gradient (mobile dune, semi-fixed dune, fixed dune, dry meadow, wet meadow and flood plain grasslands) of natural sandy grasslands in semiarid areas of northern China. We used multivariate analysis to examine the relationships between environmental factors, vegetation composition, plant diversity and productivity. We found a positive correlation between plant diversity and productivity. Vegetation composition aggregated by the ordination technique of non-metric multidimensional scaling had also a significantly positive correlation with plant diversity and productivity. Environmental gradients in relation to soil and topography affected the distribution patterns of vegetation composition, species diversity and productivity. However, environmental gradients were a better determinant of vegetation composition and productivity than of plant diversity. Structural equation modeling suggested that environmental factors determine vegetation composition, which in turn independently drives both plant diversity and productivity. Thus, the positive correlation between plant diversity and productivity is indirectly driven by vegetation composition, which is determined by environmental gradients in soil and topography.


2013 ◽  
Vol 11 (3) ◽  
Author(s):  
Dyan Vidyatmoko ◽  
Bunasor Sanim ◽  
Hermanto Siregar ◽  
M. Said Didu

The objectives of this research were (1) to analyse determinants of the influencing factors of the Indonesian Estate State-owned enterprises’ executive compensations; and (2) to analyse the relationship between compensation executive and firm performances. Statistical methods used for analysing these objectives were Structural Equation Model (SEM), contingency analysis, regresion analysis and qualitative analysis. The study found out that from all identified variables, executive decision mechanism, job complexity, firm size, firm ability to pay compensation, and product diversification and market expansionhad positive correlation and significant influenced to executive compensation. Human capital, business risk, executive employment market had significant correlations to executive compensation. The research had also shown a result that executive compensation provide positive correlation and significant influence towards financial performance (EBIT), customer performance (sales volume, output price, market area), internal process performance (OER target, OER realisation), and growth and learning performance (number of training investment, number of employees participated intraining). However, executive compensation did not give positive correlation and significant influenced towards financial performance (ROE) and customer performance(market share). This research also showed that direction of executive compensation was heading to company’s performance and not the opposite way.


2021 ◽  
Vol 13 (9) ◽  
pp. 5013
Author(s):  
Dan Zhu ◽  
Degang Yang

Identifying how policy, socioeconomic factors, and environmental factors influence changes in human well-being (HWB) and conservation efficiency is important for ecological management and sustainable development, especially in the Giant Panda National Park (GPNP). In this study, we systematically analyzed the differences in the conservation status of the giant panda habitat and changes in HWB over 15 years in the GPNP, which includes six mountain sites, Minshan (MS), Qionglai (QLS), Xiaoxiangling (XXL), Liangshan (LS), Qinling (QL), and Daxiangling (DXL). Redundancy analyses were used to determine the factors contributing (policy, socioeconomic factors, and environmental factors) to HWB and giant panda habitat conservation (HC). In addition, using a structural equation model (SEM), we investigated the relationship between the aforementioned three factors and their direct and indirect effects on HWB and HC. The results indicated that there was spatiotemporal heterogeneity of HWB and HC in our study area. There was an increasing number of plant species as well as an increased number of giant panda in GPNP. Generally, HWB in 2015 showed an increasing trend compared with that in 2000. Socioeconomic factors (23.6%) have the biggest influence on HWB and HC, followed by policy (23.2%) and environmental factors (19.4%). Conservation policy had a significantly positive influence on HWB (0.52), while it negatively influenced HC (−0.15). Socioeconomic factors significantly negatively influenced HWB (−0.38). The formulation and implementation of policies to promote economic development will contribute to the protection of giant pandas and their habitat. Our results provide insight on the conservation status of the giant panda habitat, HWB, and factors influencing them in different mountain sites in the GPNP, as well as having implications for the future management of the GPNP.


Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 534
Author(s):  
Pavel Samec ◽  
Jiří Volánek ◽  
Miloš Kučera ◽  
Pavel Cudlín

Plant distribution is most closely associated with the abiotic environment. The abiotic environment affects plant species’ abundancy unevenly. The asymmetry is further deviated by human interventions. Contrarily, soil properties preserve environmental influences from the anthropogenic perturbations. The study examined the supra-regional similarities of soil effects on plant species’ abundance in temperate forests to determine: (i) spatial relationships between soil property and forest-plant diversity among geographical regions; (ii) whether the spatial dependencies among compared forest-diversity components are influenced by natural forest representation. The spatial dependence was assessed using geographically weighted regression (GWR) of soil properties and plant species abundance from forest stands among 91 biogeographical regions in the Czech Republic (Central Europe). Regional soil properties and plant species abundance were acquired from 7550 national forest inventory plots positioned in a 4 × 4 km grid. The effect of natural forests was assessed using linear regression between the sums of squared GWR residues and protected forest distribution in the regions. Total diversity of forest plants is significantly dependent on soil-group representation. The soil-group effect is more significant than that of bedrock bodies, most of all in biogeographical regions with protected forest representation >50%. Effects of soil chemical properties were not affected by protected forest distribution. Spatial dependency analysis separated biogeographical regions of optimal forest plant diversity from those where inadequate forest-ecosystem diversity should be increased alongside soil diversity.


Medicina ◽  
2021 ◽  
Vol 57 (3) ◽  
pp. 275
Author(s):  
Natsuko Matsumoto ◽  
Jonguk Park ◽  
Rie Tomizawa ◽  
Hitoshi Kawashima ◽  
Koji Hosomi ◽  
...  

Background and Objectives: The gut microbiota is associated with human health and dietary nutrition. Various studies have been reported in this regard, but it is difficult to clearly analyze human gut microbiota as individual differences are significant. The causes of these individual differences in intestinal microflora are genetic and/or environmental. In this study, we focused on differences between identical twins in Japan to clarify the effects of nutrients consumed on the entire gut microbiome, while excluding genetic differences. Materials and Methods: We selected healthy Japanese monozygotic twins for the study and confirmed their zygosity by matching 15 short tandem repeat loci. Their fecal samples were subjected to 16S rRNA sequencing and bioinformatics analyses to identify and compare the fluctuations in intestinal bacteria. Results: We identified 12 genera sensitive to environmental factors, and found that Lactobacillus was relatively unaffected by environmental factors. Moreover, we identified protein, fat, and some nutrient intake that can affect 12 genera, which have been identified to be more sensitive to environmental factors. Among the 12 genera, Bacteroides had a positive correlation with retinol equivalent intake (rs = 0.38), Lachnospira had a significantly negative correlation with protein, sodium, iron, vitamin D, vitamin B6, and vitamin B12 intake (rs = −0.38, −0.41, −0.39, −0.63, −0.42, −0.49, respectively), Lachnospiraceae ND3007 group had a positive correlation with fat intake (rs = 0.39), and Lachnospiraceae UCG-008 group had a negative correlation with the saturated fatty acid intake (rs = −0.45). Conclusions: Our study is the first to focus on the relationship between human gut microbiota and nutrient intake using samples from Japanese twins to exclude the effects of genetic factors. These findings will broaden our understanding of the more intuitive relationship between nutrient intake and the gut microbiota and can be a useful basis for finding useful biomarkers that contribute to human health.


2021 ◽  
Vol 13 (11) ◽  
pp. 6221
Author(s):  
Muyuan Ma ◽  
Yaojun Zhu ◽  
Yuanyun Wei ◽  
Nana Zhao

To predict the consequences of environmental change on the biodiversity of alpine wetlands, it is necessary to understand the relationship between soil properties and vegetation biodiversity. In this study, we investigated spatial patterns of aboveground vegetation biomass, cover, species diversity, and their relationships with soil properties in the alpine wetlands of the Gannan Tibetan Autonomous Prefecture of on the Qinghai-Tibetan Plateau, China. Furthermore, the relative contribution of soil properties to vegetation biomass, cover, and species diversity were compared using principal component analysis and multiple regression analysis. Generally, the relationship between plant biomass, coverage, diversity, and soil nutrients was linear or unimodal. Soil pH, bulk density and organic carbon were also significantly correlated to plant diversity. The soil attributes differed in their relative contribution to changes in plant productivity and diversity. pH had the highest contribution to vegetation biomass and species richness, while total nitrogen was the highest contributor to vegetation cover and nitrogen–phosphorus ratio (N:P) was the highest contributor to diversity. Both vegetation productivity and diversity were closely related to soil properties, and soil pH and the N:P ratio play particularly important roles in wetland vegetation biomass, cover, and diversity.


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