Importance Of Riparian Vegetation Research Articles

Importance of riparian vegetation and wood-pastures in the maintenance of bat assemblages in a highly fragmented landscape in Veracruz, Mexico

Abstract To investigate whether trees and palms scattered in pastures contribute to the maintenance of bat assemblages in landscapes highly fragmented by livestock farming activities, we evaluated the bat assemblages and foraging guilds between wooded pastures and riparian vegetation. Using mist nets, we captured 1013 bats from 29 species and four taxonomic families. We found that the abundance, richness, and composition of bat species were not significantly different between vegetation types. Frugivores were the most abundant guild, and their abundance did not differ between vegetation types, indicating that wood-pastures allow the presence of these bats in the landscape. On the other hand, insectivores were more abundant in riparian vegetation and, interestingly, nectarivores were more abundant in pastures, likely due to the great plasticity of species of the genus Glossophaga. Our results are encouraging, since they demonstrate that a rustic pasture management that promoting the presence of scattered trees and palms along with belts of riparian vegetation, allows the maintenance of bat assemblages in a highly fragmented landscape.

Influence of riparian vegetation on flow resistance in mobile bed straight compound channels

Riparian vegetation is an important feature in rivers and essential in hydraulic engineering including flood management and river restoration. Deforestation activities have been pointed out as a contributing factor to the severity of flood damages. This shows that the importance of riparian vegetation in river restoration schemes in order to lessen the issues of flood risk and flood protection. The riparian vegetation creates additional resistance to flood flow which resulted in velocity reduction, increasing of flow depth and transportation of sediment in rivers. The hydraulics of flood flows in vegetated floodplain of mobile bed straight channel was experimented in the Hydraulics Laboratory, Faculty of Civil Engineering, Universiti Teknologi Malaysia. Two-lined steel rods with tandem and staggered arrays to simulate as rigid emergent vegetation were placed along the riparian zone of an asymmetrical channel. The flow resistance including Manning’s n, Darcy’s f and drag force, FD were studied. The findings showed that the riparian vegetation had increased the Manning’s n by 20%. Meanwhile, staggered arrangement of vegetation was found to generate the highest Darcy’s f of about 16% as compared to tandem arrangement. The presence of riparian vegetation also found to induce 20% more drag force compared to the main channel roughness effect. The dramatically changes of bed morphology also led to the increase of the flow resistance in the channel.

Dieta de <em>Astyanax asuncionensis</em> (Characiformes, Characidae), em riachos da bacia do rio Cuiabá, Estado do Mato Grosso

The goal of this study was to assess the diet of A. asuncionensis in four streams. Fish samples were carried out monthly from January to December 2003, using electrofishing. Stomach contents of 213 individuals were analyzed, and the diet was described as for occurrence and volumetric percentage of each item combined in a feeding index (IAi). The diet composition, importance of allochthonous and autochthonous resources, and diet breadth (Levin’s index) were assessed among streams and between seasons (dry and rainy). The diet was composed of 22 feeding items; allochthonous resources (especially insects) dominated the diet in all streams and in both seasons. The highest values of diet breadth were recorded, in general, during the rainy period. These results showed that A. asuncionensis populations are supported by terrestrial food (especially Hymenoptera), indicating the importance of riparian vegetation. Considering that streams differ according to riparian vegetation cover, our results indicate that the maintenance of vegetation and recovery of degraded areas are essential for conservation of this fish species in these streams

Use by birds of riparian vegetation in an extensively fragmented landscape

The bird communities of six riparian woodland sites are described and compared with those of eight terrestrial woodland sites in the Central Tablelands near Bathurst, New South Wales, Australia. Riparian woodland, where still present in the Central Tablelands, is dominated by either relatively narrow strips of Casuarina cunninghamiana along stream banks or the less restricted Angophora floribunda trees associated with Eucalyptus melliodora?E. blakelyi woodlands. Four of the riparian sites were located within cleared agricultural land and two were located within a relatively large nature reserve. Bird censuses along a strip transect were conducted twice per season from spring 1993 to summer 1996. The riparian woodland communities contained within the cleared landscape of the Bathurst basin were found to support a diverse avifauna, a mix of woodland-forest and species associated with agricultural landscapes. Extensive observations of individual birds at riparian sites indicate that the tree canopy is the most widely used microhabitat stratum. While native riparian woodlands are generally degraded, their connectivity and stabilizing function (actual or potential) identifies them as a critical landscape component in maintenance or restoration programmes. Hence it is suggested that riparian strips could form the basis for rehabilitation initiatives within this landscape. Fenced plantings of endemic tree species supplemented by native understorey species could be linked with existing vegetation to enhance landscape connectivity. It is crucial that landholders become aware of the importance of riparian vegetation for nature conservation and stream stabilization. Incentives should be provided to landholders to encourage these areas to be fenced from stock in order to protect them from further degradation in a significantly disturbed ecosystem.