Termite mound vegetation patterns are largely driven by stochastic rather than deterministic processes at regional scale in Africa: A meta‐analysis

2020 ◽  
Vol 31 (4) ◽  
pp. 540-550
Author(s):  
Justice Muvengwi ◽  
Edward T. F. Witkowski
Keyword(s):  
Meta Analysis ◽  
Regional Scale ◽  
Vegetation Patterns ◽  
Termite Mound ◽  
Deterministic Processes

scholarly journals Evaluation of the Regional-Scale Optimal K Rate Based on Sustainable Apple Yield and High-Efficiency K Use in Loess Plateau and Bohai Bay of China: A Meta-Analysis

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1368
Author(s):  
Wenzheng Tang ◽  
Wene Wang ◽  
Dianyu Chen ◽  
Ningbo Cui ◽  
Haosheng Yang ◽  
...  
Keyword(s):  
Loess Plateau ◽  
High Efficiency ◽  
Meta Analysis ◽  
Regional Scale ◽  
Fertilizer Application ◽  
Application Rate ◽  
Bohai Bay ◽  
The Loess Plateau ◽  
Application Rates ◽  
Relationship Model

In order to meet the growing food demand of the global population and maintain sustainable soil fertility, there is an urgent need to optimize fertilizer application amount in agricultural production practices. Most of the existing studies on the optimal K rates for apple orchards were based on case studies and lack information on optimizing K-fertilizer management on a regional scale. Here, we used the method of combining meta-analysis with the K application rate-yield relationship model to quantify and summarize the optimal K rates of the Loess Plateau and Bohai Bay regions in China. We built a dataset based on 159 observations obtained from 18 peer-reviewed literature studies distributed in 15 different research sites and evaluated the regional-scale optimal K rates for apple production. The results showed that the linear plus platform model was more suitable for estimating the regional-scale optimal K rates, which were 208.33 and 176.61 kg K ha−1 for the Loess Plateau and Bohai Bay regions of China, respectively. Compared with high K application rates, the optimal K rates increased K use efficiency by 45.88–68.57%, with almost no yield losses. The optimal K rates also enhanced the yield by 6.30% compared with the low K application rates.

scholarly journals Different effects of invader–native phylogenetic relatedness on invasion success and impact: a meta-analysis of Darwin's naturalization hypothesis

2016 ◽  
Vol 283 (1838) ◽  
pp. 20160663 ◽  
Author(s):  
Chao Ma ◽  
Shao-peng Li ◽  
Zhichao Pu ◽  
Jiaqi Tan ◽  
Manqiang Liu ◽  
...  
Keyword(s):  
Alien Species ◽  
Meta Analysis ◽  
Regional Scale ◽  
Local Scale ◽  
Invasion Success ◽  
Native Communities ◽  
Invasion Stage ◽  
Investigation Methods ◽  
Darwin's Naturalization Hypothesis ◽  
Darwin’S Naturalization Hypothesis

Darwin's naturalization hypothesis (DNH), which predicts that alien species more distantly related to native communities are more likely to naturalize, has received much recent attention. The mixed findings from empirical studies that have tested DNH, however, seem to defy generalizations. Using meta-analysis to synthesize results of existing studies, we show that the predictive power of DNH depends on both the invasion stage and the spatial scale of the studies. Alien species more closely related to natives tended to be less successful at the local scale, supporting DNH; invasion success, however, was unaffected by alien–native relatedness at the regional scale. On the other hand, alien species with stronger impacts on native communities tended to be more closely related to natives at the local scale, but less closely related to natives at the regional scale. These patterns are generally consistent across different ecosystems, taxa and investigation methods. Our results revealed the different effects of invader–native relatedness on invader success and impact, suggesting the operation of different mechanisms across invasion stages and spatial scales.

The influence of termite-induced heterogeneity on savanna vegetation along a climatic gradient in West Africa

2012 ◽  
Vol 29 (1) ◽  
pp. 11-23 ◽  
Author(s):  
Arne Erpenbach ◽  
Markus Bernhardt-Römermann ◽  
Rüdiger Wittig ◽  
Adjima Thiombiano ◽  
Karen Hahn
Keyword(s):  
West Africa ◽  
Plant Species ◽  
Large Scale ◽  
Regional Scale ◽  
Soil Conditions ◽  
Soil Parameters ◽  
Climatic Gradient ◽  
Termite Mound ◽  
Savanna Vegetation ◽  
Bioclimatic Variables

Abstract:Termites are renowned ecosystem engineers. Their mounds have been described as an important element of savanna vegetation dynamics, but little is known about their large-scale impact on vegetation composition. To investigate the influence of termite-induced heterogeneity in savannas along a climatic gradient in West Africa termite mound vegetation was compared with adjacent savanna vegetation using 256 paired plots (size of the termite mound and a corresponding savanna area) in five protected areas from northern Burkina Faso to northern Benin. On each plot vegetation and soil sampling was performed. Additionally bioclimatic variables from the WORLDCLIM database were used. The vegetation on the mounds and the surrounding savanna differed within all study sites (DCA length of gradient 3.85 SD) and showed complete turnover along the climatic gradient (DCA length of gradient 5.99 SD). Differences between mounds and savanna were significantly related to termite-induced changes in soil parameters, specifically clay enrichment and increased cation concentrations (base saturation). On a local scale, termite-induced differences in soil conditions were found to be the most important factor affecting mound vegetation, while on a regional scale, annual precipitation showed the strongest significant correlations. However, with increasing precipitation, differences between mounds and the surrounding matrix became more pronounced, and the contribution of mounds to local phytodiversity increased. Eleven plant species were identified as characteristic termite mound species. In the more humid parts of the gradient, more characteristic plant species were found that may benefit from favourable soil conditions, good water availability, and a low fire impact in the mound microhabitat.

The effect of vegetation patterns on wind-blown mass transport at the regional scale: A wind tunnel experiment

Geomorphology ◽  
2012 ◽  
Vol 159-160 ◽  
pp. 178-188 ◽  
Author(s):  
Feras Youssef ◽  
Saskia M. Visser ◽  
Derek Karssenberg ◽  
Gunay Erpul ◽  
Wim M. Cornelis ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Mass Transport ◽  
Regional Scale ◽  
Wind Tunnel Experiment ◽  
Vegetation Patterns

Regional Vegetation Histories: An Overview of the Pollen Evidence from the Central Mediterranean

2015 ◽  
Vol 11 (1) ◽  
pp. 69-82 ◽  
Author(s):  
Katerina Kouli ◽  
Alessia Masi ◽  
Anna Maria Mercuri ◽  
Assunta Florenzano ◽  
Laura Sadori
Keyword(s):  
Land Use ◽  
Human Impact ◽  
Environmental Conditions ◽  
Regional Scale ◽  
Great Variability ◽  
Vegetation Patterns ◽  
Pollen Record ◽  
Central Mediterranean ◽  
Temporal Fluctuations ◽  
Interdisciplinary Study

Abstract Vegetation patterns during the 1st millennium AD in the central Mediterranean, exhibit a great variability, due to the richness of these habitats and the continuous shaping of the environment by human societies. Variations in land use, witnessed in the pollen record, reflect the role that local vegetation and environmental conditions played in the choices made by local societies. The interdisciplinary study of off-site cores remains the key evidence for palaeoenvironmental transformations mirroring the ‘semi-natural’ vegetation, and revealing temporal fluctuations and the amount of human impact on a regional scale.

scholarly journals Success of coastal wetlands restoration is driven by sediment availability

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Zezheng Liu ◽  
Sergio Fagherazzi ◽  
Baoshan Cui
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Coastal Wetlands ◽  
Coastal Wetland ◽  
Meta Analysis ◽  
Regional Scale ◽  
Global Strategy ◽  
Sediment Supply ◽  
Tidal Range ◽  
Coastal Protection

AbstractShorelines and their ecosystems are endangered by sea-level rise. Nature-based coastal protection is becoming a global strategy to enhance coastal resilience through the cost-effective creation, restoration and sustainable use of coastal wetlands. However, the resilience to sea-level rise of coastal wetlands created under Nature-based Solution has been assessed largely on a regional scale. Here we assess, using a meta-analysis, the difference in accretion, elevation, and sediment deposition rates between natural and restored coastal wetlands across the world. Our results show that restored coastal wetlands can trap more sediment and that the effectiveness of these restoration projects is primarily driven by sediment availability, not by wetland elevation, tidal range, local rates of sea-level rise, and significant wave height. Our results suggest that Nature-based Solutions can mitigate coastal wetland vulnerability to sea-level rise, but are effective only in coastal locations where abundant sediment supply is available.

scholarly journals Digital Elevation Models of Rockfalls and Landslides: A Review and Meta-Analysis

Geosciences ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 256
Author(s):  
Maria P. Kakavas ◽  
Konstantinos G. Nikolakopoulos
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Structural Characteristics ◽  
Digital Elevation Models ◽  
Meta Analysis ◽  
Regional Scale ◽  
Major Question ◽  
Medium Resolution ◽  
Digital Elevation ◽  
Landslide Event

The scope of this paper is to summarize previous research pertaining to the use of digital elevation models (DEMs) and digital terrain models (DTMs) in the study of rockfalls and landslides. Research from 1983 to 2020 was surveyed in order to understand how the spatial resolution of DEMs and DTMs affects landslide detection, validation, and mapping. Another major question examined was the relationship between the DEM resolution and the extent of the rockfall or landslide event. It emerged from the study that, for landslides, the majority of researchers used DEMs with a spatial resolution of between 10 m and 30 m, while for rockfalls, they used DEMs with a spatial resolution of between 5 m and 20 m. We concluded that DEMs with a very high resolution (less than 5 m) are suitable for local-scale occurrences, while medium-resolution (from 20 m to 30 m) DEMs are suitable for regional-scale events. High resolution is associated with high accuracy and detailed structural characteristics, while medium accuracy better illustrates the topographic features. A low pixel size (more than 90 m) is not recommended for this type of research. Susceptibility maps, inventory maps, hazard risk zones, and vulnerability assessments are some of the main tools used in landslide/rockfall investigations, and topographic indexes, methods, models, and software optimize the reliability of the results. All of these parameters are closely related to DEMs and DTMs as the cell size affects the credibility of the final outcome.

scholarly journals A nonlinear relationship between marsh size and sediment trapping capacity compromises salt marshes’ stability

Geology ◽  
2020 ◽  
Vol 48 (10) ◽  
pp. 966-970 ◽  
Author(s):  
Carmine Donatelli ◽  
Xiaohe Zhang ◽  
Neil K. Ganju ◽  
Alfredo L. Aretxabaleta ◽  
Sergio Fagherazzi ◽  
...  
Keyword(s):  
Salt Marshes ◽  
Meta Analysis ◽  
Regional Scale ◽  
The United States ◽  
Sediment Supply ◽  
Intertidal Area ◽  
Sediment Trapping ◽  
Marsh Erosion ◽  
The Impact ◽  
Salt Marsh Area

Abstract Global assessments predict the impact of sea-level rise on salt marshes with present-day levels of sediment supply from rivers and the coastal ocean. However, these assessments do not consider that variations in marsh extent and the related reconfiguration of intertidal area affect local sediment dynamics, ultimately controlling the fate of the marshes themselves. We conducted a meta-analysis of six bays along the United States East Coast to show that a reduction in the current salt marsh area decreases the sediment availability in estuarine systems through changes in regional-scale hydrodynamics. This positive feedback between marsh disappearance and the ability of coastal bays to retain sediments reduces the trapping capacity of the whole tidal system and jeopardizes the survival of the remaining marshes. We show that on marsh platforms, the sediment deposition per unit area decreases exponentially with marsh loss. Marsh erosion enlarges tidal prism values and enhances the tendency toward ebb dominance, thus decreasing the overall sediment availability of the system. Our findings highlight that marsh deterioration reduces the sediment stock in back-barrier basins and therefore compromises the resilience of salt marshes.

Sign in / Sign up

Export Citation Format

Share Document