Declines in Vegetation Patches, Plant Diversity, and Grasshopper Diversity Near Cattle Watering-Points in the Victoria River District, Northern Australia.

1999 ◽  
Vol 21 (1) ◽  
pp. 135 ◽  
Author(s):  
JA Ludwig ◽  
RW Eager ◽  
RJ Williams ◽  
LM Lowe

In this study, we quantify the density, cover and obstruction width of vegetation patches, the roughness of landscape surfaces, and the diversities of plants and grasshoppers with distance from cattle watering- points. We used distance from water as a surrogate for a gradient in grazing pressure. Fourteen study sites were located in the Victoria River District of northern Australia, seven from a water point on Kidman Springs Station on calcareous red loam soils and seven from a water point at Mount Sanford Station on craclcing-clay black soils. At each study site transect lines were oriented within the landscape to run downslope (i.e. in the direction of flows of run-off). We measured the intercept length and obstruction width of perennial vegetation patches along these lines. Plant diversity was measured in quadrats positioned along each line and grasshopper diversity was determined by species counts on each site. We also surveyed the roughness of the landscape surface along each line. A rough surface will tend to slow run-off. hence increase time for water infiltration and soil-water storage. Surface roughness declined near water, as did the density, cover and obstruction width of perennial vegetation patches. Grasshopper and plant species richness also declined near water. These declines suggest strong linkages between landscape filmtion. biodiversity and inipacts of cattle grazing and trampling. Cattle will always create 'sacrifice zones' around watering-points. However, the area of this impact on function and diversity can be minimised by managing the timing and intensity of paddock use. Key words: grazing gradients. Kidman Springs, landscape function. Mount Sanford, piosphere, surface roughness, tropical grasslands, tropical savannas

2014 ◽  
Vol 45 (4) ◽  
pp. 176 ◽  
Author(s):  
Mario Pirastru ◽  
Marcello Niedda ◽  
Mirko Castellini

Many hillslopes covered with maquis in the semi-arid Mediterranean environment have been cleared in recent decades. There is little information on what effect this has on the hydrology of the soil. We compared the hydraulic properties of the soil and the subsurface hydrological dynamics on two adjacent sites on a hillslope. One site was covered with maquis, the other with grass. The grass started to grow some 10 years ago, after the maquis had been cleared and the soil had been ploughed. Our study found that the hydraulic properties and the hydrological dynamics of the maquis and the grassed soil differed greatly. The grassed soil had less organic matter and higher apparent density than did the soil covered in maquis. Moreover, the maquis soil retained more water than the grassed soil in the tension range from saturation to 50 cm of water. Infiltration tests performed in summer and in winter indicated that the field saturated hydraulic conductivity (K<sub>fs</sub>) of the maquis soil was higher than that of the grassy soil. However the data showed that the K<sub>fs</sub> of the two soils changed with the season. In the maquis soil the K<sub>fs</sub> increased from summer to winter. This was assumed to be due to water flowing more efficiently through wet soil. By contrast, in the grassy soil the K<sub>fs</sub> decreased from summer to winter. This was because the desiccation cracks closed in the wet soil. As result, the influence of the land use change was clear from the K<sub>fs</sub> measurements in winter, but less so from those in the summer. Changes in land use altered the dynamics of the infiltration, subsurface drainage and soil water storage of the soil. The maquis soil profile never saturated completely, and only short-lived, event based perched water tables were observed. By contrast, soil saturation and a shallow water table were observed in the grass covered site throughout the wet season. The differences were assumed to be due to the high canopy interception of the maquis cover, and to the macropores in the grassed soil being destroyed after the maquis had been cleared and the soil ploughed. The results of this work are helpful for predicting the changes in the hydraulic properties of the soil and in the near-surface hydrological processes in similar Mediterranean environments where the natural vegetation has been cleared. These changes must be taken into consideration when developing rainfall-runoff models for flood forecasting and water yield evaluation.


Plants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 369 ◽  
Author(s):  
Araújo ◽  
Moreira ◽  
Falcão ◽  
Borges ◽  
Fagundes ◽  
...  

Host plants may harbor a variable number of galling insect species, with some species being able to harbor a high diversity of these insects, being therefore called superhost plants. In the present study, we tested the hypothesis that the occurrence of superhost plant species of genus Qualea (Vochysiaceae) affects the structure of plant–galling insect ecological networks in Brazilian Cerrado. We sampled a total of 1882 plants grouped in 131 species and 43 families, of which 64 species and 31 families of host plants hosted 112 galling insect species. Our results showed that occurrence of superhosts of genus Qualea increased the linkage density of plant species, number of observed interactions, and the size of plant–galling insect networks and negatively affected the network connectance (but had no effect on the residual connectance). Although the occurrence of Qualea species did not affect the plant species richness, these superhosts increased the species richness and the number of interactions of galling insects. Our study represents a step forward in relation to previous studies that investigated the effects of plant diversity on the plant–insect networks, showing that few superhost plant species alter the structure of plant–herbivore networks, even without having a significant effect on plant diversity.


2020 ◽  
Vol 12 (14) ◽  
pp. 2201 ◽  
Author(s):  
Hua-Feng Wang ◽  
Xia-Lan Cheng ◽  
Mir Muhammad Nizamani ◽  
Kelly Balfour ◽  
Liangjun Da ◽  
...  

Understanding the factors that drive green space composition and richness in heterogeneous urban landscapes is critical for maintaining important ecosystem services and biodiversity. Few studies have been conducted on urban greening and plant diversity at the urban functional unit (UFU) level, although a handful of studies have explored the drivers of greening percentage and its relationships with plant richness in tropical cities. In this study, we conducted field surveys, compiled census and remote sensing data, and performed spatial analyses to investigate the interrelationship between greening percentages, plant diversity, and the socioeconomic variables of different primary and secondary UFUs in the cities of Beijing, Zhanjiang, and Haikou in China. We found that these relationships did not differ significantly between primary and secondary UFUs, and that Parks represented the largest areas of forested land, grassland, and water bodies across all three cities. Moreover, the greening percentages of all UFUs across these three cities were positively correlated with both socioeconomic variables and plant species richness. These relationships can be utilized to guide future green space planning within urban ecosystems.


2008 ◽  
Vol 8 (4) ◽  
pp. 231-238 ◽  
Author(s):  
Patricia Göbel ◽  
Julia Zimmermann ◽  
Christoph Klinger ◽  
Holger Stubbe ◽  
Wilhelm G. Coldewey

1979 ◽  
Vol 10 (1) ◽  
pp. 5-12 ◽  
Author(s):  
G C Chisci

Clay soils of the Italian Apennines are subject to erosion and landslides. Up-and-down-slope deep ploughing in preparation for the winter cereal crop can aggravate such erosion. Alternative techniques are minimum tillage which enhances water infiltration, the use of soil conditioners, and tile drainage transversely to the maximum slope to control run-off. But the provision of a legume forage crop cover probably represents the most generally effective conservation measure.


2019 ◽  
Vol 2 ◽  
pp. 782
Author(s):  
Hery Haryanto

This essay is a summary of training activity of water conservation and application of biopori holes at two villages in Bengkulu Province, i.e. Pering Baru village surrounded by palm cultivation, Suro Lembak dominated by vegetable farming. Both villages were experienced  with shortage of water during dry season, and plenty of water during rainy season. So people from both villages were eager to be trained on water conservation and implementation of biopori hole. Water conservation in palm plantation and vegetable farming were done by making ditches perpendicular with the slope of lands in order to collect run off water, and lead to infiltration. Moreover,  biopori holes could be constructed  around their homes in order to increase water infiltration, and also to be used as organic waste digester for producing composts. This biopori holes protected  from malaria diseases due to no more stagnant water. 


2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Martin Hejda ◽  
Jan Čuda ◽  
Klára Pyšková ◽  
Guin Zambatis ◽  
Llewellyn C. Foxcroft ◽  
...  

AbstractTo identify factors that drive plant species richness in South-African savanna and explore their relative importance, we sampled plant communities across habitats differing in water availability, disturbance, and bedrock, using the Kruger National Park as a model system. We made plant inventories in 60 plots of 50 × 50 m, located in three distinct habitats: (i) at perennial rivers, (ii) at seasonal rivers with water available only during the rainy season, and (iii) on crests, at least ~ 5 km away from any water source. We predicted that large herbivores would utilise seasonal rivers’ habitats less intensely than those along perennial rivers where water is available throughout the year, including dry periods. Plots on granite harboured more herbaceous and shrub species than plots on basalt. The dry crests were poorer in herb species than both seasonal and perennial rivers. Seasonal rivers harboured the highest numbers of shrub species, in accordance with the prediction of the highest species richness at relatively low levels of disturbance and low stress from the lack of water. The crests, exposed to relatively low pressure from grazing but stressed by the lack of water, are important from the conservation perspective because they harbour typical, sometimes rare savanna species, and so are seasonal rivers whose shrub richness is stimulated and maintained by the combination of moderate disturbance imposed by herbivores and position in the middle of the water availability gradient. To capture the complexity of determinants of species richness in KNP, we complemented the analysis of the above local factors by exploring large-scale factors related to climate, vegetation productivity, the character of dominant vegetation, and landscape features. The strongest factor was temperature; areas with the highest temperatures reveal lower species richness. Our results also suggest that Colophospermum mopane, a dominant woody species in the north of KNP is not the ultimate cause of the lower plant diversity in this part of the park.


Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1312 ◽  
Author(s):  
Majed Abu-Zreig ◽  
Haruyuki Fujimaki ◽  
Mohamed Ahmed Abd Elbasit

Enhancing rainwater infiltration into heavy soils is an important strategy in arid regions to increase soil water storage and meet crop water demand. In such soils, water infiltration and deep percolation can be enhanced by constructing deep ditches filled with permeable materials, such as sand. Laboratory experiments were conducted to examine the effect of sand ditch installed across the slope of a soil box, 50 × 20 × 20 cm3, on runoff interception and water infiltration of clay soil packed at two bulk densities, 1240 and 1510 kg/m3. The experiments were carried out under laboratory conditions using simulated steady flow of about 20 cm/h for a duration of 60 min. Results showed that sand ditches highly reduced runoff and largely enhanced water infiltration into soils. In low-density soil, the average runoff was 15% of inflow volume but reduced to zero in the presence of sand ditches thus increasing soil water storage by 15%. In high-density soil, the presence of sand ditches was more effective; infiltration volume increased by 156% compared to control. The WASH_2D model was used to simulate water flow in the presence of sand ditches; it showed to increase water infiltration and soil-moisture storage thus improving crop production in drylands.


2020 ◽  
Author(s):  
Melanie Tietje ◽  
William J. Baker ◽  
Rafaël Govaerts ◽  
Stephen A. Smith ◽  
Miao Sun ◽  
...  

&lt;p&gt;Spatial patterns of plant diversity follow the well-known global latitudinal biodiversity gradient, however there is little consensus about the underlying causes for this pattern. Here we present a spatial analysis of a complete checklist of the world&amp;#8217;s seed plants, integrated with a comprehensive plant Tree of Life. This combination allows insights into the evolutionary drivers of plant species richness patterns, specifically current plant biodiversity patterns, and the diversification processes that shaped them. Our study provides a comprehensive global species richness map and relates the observed species richness pattern to speciation rates derived from phylogeny, and with environmental variables, which are hypothesized to impact speciation rates. Initial results show that tropical rain forest regions, although being areas that contain among the highest numbers of species, are regions with comparatively low speciation rates, contradicting the widespread notion that rainforests are &amp;#8220;cradles&amp;#8221; of biodiversity. This finding seems further supported by contrasting association of environmental variables, like precipitation and temperature, with speciation rates and species richness.&lt;/p&gt;


Sign in / Sign up

Export Citation Format

Share Document