Coastal vegetation structures and their functions in tsunami protection: experience of the recent Indian Ocean tsunami

This study explored the effects of coastal vegetation on tsunami damage based on field observations carried out after the Indian Ocean tsunami on 26 December 2004. Study locations covered about 250 km (19 locations) on the southern coast of Sri Lanka and about 200 km (29 locations) on the Andaman coast of Thailand. The representative vegetation was classified into six types according to their habitat and the stand structures of the trees. The impact of vegetation structure on drag forces was analyzed using the observed characteristics of the tree species. The drag coefficient, including the vertical stand structures of trees, C _d-all, and the vegetation thickness (cumulative trunk diameter of vegetation in the tsunami direction) per unit area, dN _u (d: reference diameter of trees, N _u : number of trees per unit area), varied greatly with the species classification. Based on the field survey and data analysis, Rhizophora apiculata and Rhizophora mucronata (hereafter R. apiculata-type), kinds of mangroves, and Pandanus odoratissimus, a representative tree that grows in beach sand, were found to be especially effective in providing protection from tsunami damage due to their complex aerial root structure. Two layers of vegetation in the vertical direction with P. odoratissimus and Casuarina equisetifolia and a horizontal vegetation structure of small and large diameter trees were also important for increasing drag and trapping floating objects, broken branches, houses, and people. The vertical structure also provided an effective soft landing for people washed up by the tsunami or for escaping when the tsunami waves hit, although its dN _u is not large compared with R. apiculata-type and P. odoratissimus. In addition, the creeks inside mangroves and the gaps inside C. equisetifolia vegetation are assumed to be effective for retarding tsunami waves. This information should be considered in future coastal landscape planning, rehabilitation, and coastal resource management.     

Vegetation bioshields for tsunami mitigation: review of effectiveness, limitations, construction, and sustainable management

Coastal vegetation has been widely recognized as a natural method to reduce the energy of tsunami waves. However, a vegetation barrier cannot completely stop a tsunami, and its effectiveness depends on the magnitude of the tsunami as well as the structure of the vegetation. For coastal rehabilitation, optimal planning of natural coastal systems, and their maintenance, we need to quantitatively elucidate the capacity of vegetation to reduce the energy of tsunami waves. The limitations of coastal forests in relation to the magnitude of a tsunami and the maintenance of forests as natural disaster buffer zones have to be understood correctly for effective coastal vegetation planning. Demerits of coastal forests have also been revealed: for example, an open gap in a forest (i.e., a road, river, difference in elevation, etc.) can channel and amplify a strong current by forcing it into the gap. Floating debris from broken trees also can damage surrounding buildings and hurt people. However, many studies have revealed that these demerits can be overcome with proper planning and management of mangroves and coastal forests, and that coastal vegetation has a significant potential to mitigate damage in constructed areas and save human lives by acting as buffer zones during extreme natural events. However, mangrove forests have been damaged by anthropogenic activities (i.e., tourism, shrimp farming, and industrial development), making coastal areas increasingly vulnerable to tsunamis and other natural disasters. The effectiveness of vegetation also changes with the age and structure of the forest. This highlights the fact that proper planning and management of vegetation are required to maintain the tsunami buffering function of coastal forests. Although many government and nongovernmental organizations have implemented coastal vegetation projects, many of them have been unsuccessful due to a lack of proper maintenance. A pilot project in Matara City, Sri Lanka, revealed that participation and support from local authorities and communities is essential to make the planting projects successful. An integrated coastal vegetation management system that includes utilization of the materials produced by the forest and a community participation and awareness program are proposed to achieve a sustainable and long-lasting vegetation bioshield.     

Residual effectiveness of insecticides for control of German cockroaches (Dictyoptera: Blattellidae) in food-handling establishments

Residual effectiveness of insecticides was compared for two treatment methods at various sites within two commercial kitchens. For all sites and insecticides, German cockroach, Blattella germanica (L.), mortality was greatest for treatments of cracks and crevices than for treatments of exposed surfaces. Mortality at the dishwashing site was lower than at all other sites. We attributed reduced mortality at the dishwashing site to a higher vapor pressure deficit. Mortality and the amount of insecticide residue recovered from treated surfaces were closely correlated. These data demonstrate that careful placement of residual insecticide treatments will influence their effective longevity.     

Evaluating the potential effectiveness of compensatory mitigation strategies for marine bycatch

Conservationists are continually seeking new strategies to reverse population declines and safeguard against species extinctions. Here we evaluate the potential efficacy of a recently proposed approach to offset a major anthropogenic threat to many marine vertebrates: incidental bycatch in commercial fisheries operations. This new approach, compensatory mitigation for marine bycatch (CMMB), is conceived as a way to replace or reduce mandated restrictions on fishing activities with compensatory activities (e.g., removal of introduced predators from islands) funded by levies placed on fishers. While efforts are underway to bring CMMB into policy discussions, to date there has not been a detailed evaluation of CMMB's potential as a conservation tool, and in particular, a list of necessary and sufficient criteria that CMMB must meet to be an effective conservation strategy. Here we present a list of criteria to assess CMMB that are tied to critical ecological aspects of the species targeted for conservation, the range of possible mitigation activities, and the multi-species impact of fisheries bycatch. We conclude that, overall, CMMB has little potential for benefit and a substantial potential for harm if implemented to solve most fisheries bycatch problems. In particular, CMMB is likely to be effective only when applied to short-lived and highly-fecund species (not the characteristics of most bycatch-impacted species) and to fisheries that take few non-target species, and especially few non-seabird species (not the characteristics of most fisheries). Thus, CMMB appears to have limited application and should only be implemented after rigorous appraisal on a case-specific basis; otherwise it has the potential to accelerate declines of marine species currently threatened by fisheries bycatch.     

The use of air bricks for planting roadside vegetation: A new technique to improve landscaping of steep roadsides in China's Hubei Province

Road construction is an important cause of environmental degradation, particularly in mountainous regions. However, re-establishing vegetation cover at the construction site can mitigate these problems, particularly on steep roadside slopes. In the present study, we developed two new planting techniques to increase vegetation cover on these slopes, in which planters fill the holes in air bricks (i.e., bricks with large holes that pass through the full depth of the brick) with soil, then plant grass or herbaceous species in the soil. Two variants of this technique (one in which the air bricks form a stairstep pattern, and another in which they form a smooth slope) were tested in an area with a warm climate near Shennongjia (Hubei Province) between 2006 and 2008. The new planting techniques promoted root growth, the development of a continuous vegetation cover, and the production of merchantable seeds compared with the conventional planting technique. This suggests that the air brick technique is more suitable for the study area, where the natural soils are thin, and may prove suitable for similar areas elsewhere in the world. The provisional results, based on 2 years of research, suggest that the new techniques represent a potentially valuable alternative for vegetation restoration, landscape conservation, and road maintenance/management in mountainous zones during and after highway construction. The techniques have strong potential for use in other areas. In addition, they provide a good example of using ecological engineering to increase vegetation cover on steep roadside slopes.     

Coastal dune stability: The effect of meteorological conditions and vegetation

Quantitative investigations and research conducted along the north coast of New South Wales, Australia are evaluated with respect to coastal processes, coastal alignment, meteorological data, dune dimensions, dune vegetative cover, development on the dunal area and dune management.The data available covered an assessment of the extent of dune instabilities, an assessment of long term coastline movements, a study of the effect of a cyclone and storm surge, and an assessment and evaluation of a phase of extreme coastline erosion. Specific situations are described and evaluated within the above context. The evaluations are used to determine the extent of coastal dune areas required to be designated as buffer zone in land use planning. The extent of the zone required is dependent upon expected magnitude of wave erosion. Magnitude of wave erosion was found to be proportional to the interaction of coastal processes during periods of extreme erosive factors and the beach dune characteristics for the particular section of coastline. It was found that man's influence on this natural interaction can be a dominating factor in determining beach dune characteristics and therefore the magnitude of wave erosion. — management of the beach dunal area to maintain an acceptable dynamic equilibrium of the beach dune line by a vegetated sand dune of specific dimensions is possible despite weather conditions, if a designated buffer zone is maintained.Presented at the Seventh International Biometeorological Congress, 17–23 August 1975, College Park, Maryland, USA.     

On the effectiveness of higher taxonomic ranks for vegetation analysis

The ecological value of employing taxonomic categories other than species to describe vegetation is examined by comparing the results of numerical classification. Using presence data only and an unsophisticated classification method with data from a small area, it is found that the use of generic and subgeneric categories instead of species causes little loss in interpretability. At the family and subfamily levels more sophisticated analyses probably employing quantitative data, are apparently required to achieve similar levels of interpretability. The transformation between categories is shown to be a simple matrix multiplication and some alternative transformations are briefly outlined. It is suggested that the use of different taxonomic categories in a sequence of analyses beginning with the highest category would provide a useful means of planning which could reduce the overall time required for the analysis of large data sets.     

Key indicators for assessing the effectiveness of waste management in construction projects

Effective construction and demolition (C&D) waste management is indispensable to the attainment of sustainable construction. Many endeavors so far have been made to assess C&D waste management. However, the majority of efforts have been attempted to investigate C&D waste management from an economic point of view, while very few studies have been focused on the environmental and social aspects, which are imperative to promote effective C&D waste management. This paper identifies 30 key indicators affecting the overall effectiveness of C&D waste management from a holistic perspective and develops a C&D waste management effectiveness assessment framework by integrating the key indicators identified. The assessment framework not only deepens understanding of effectiveness of C&D waste management, but also provides a concrete base for future research in assessing the effectiveness of C&D waste management quantitatively.     

The effectiveness of US mitigation and monitoring practices for the threatened Valley elderberry longhorn beetle

Habitat mitigation frequently leads to planting of new habitat, assuming that it can replace lost natural habitat. Yet this practice has rarely been examined in detail. In the USA habitat mitigation is frequently allowed under the US Endangered Species Act, providing monitoring reports which represent a potentially valuable data source for imperiled species. We used publicly available reports for the US threatened Valley elderberry longhorn beetle (Desmocerus californicus dimorphus) to assess record keeping practices used by US Fish and Wildlife Service (FWS), and the utility of such analyses for improving conservation. A large portion of mitigation reports known to exist were missing from FWS files, indicating problems with data management, and a loss of important information. Transplanted brought mature beetle host plants and beetles to sites, promoting beetle colonization. Conversely, few sites with seedlings were colonized. Results indicate a need for improved data management by FWS and longer term monitoring.     

A new set of bioinformatics tools for genome projects

A new tool called System for Automated Bacterial Integrated Annotation--SABIA (SABIA being a very well-known bird in Brazil) was developed for the assembly and annotation of bacterial genomes. This system performs automatic tasks of assembly analysis, ORFs identification/analysis, and extragenic region analyses. Genome assembly and contig automatic annotation data are also available in the same working environment. The system integrates several public domains and newly developed software programs capable of dealing with several types of databases, and it is portable to other operational systems. These programs interact with most of the well-known biological database/softwares, such as Glimmer, Genemark, the BLAST family programs, InterPro, COG, Kegg, PSORT, GO, tRNAScan and RBSFinder, and can also be used to identify metabolic pathways.     

Field evaluation of effectiveness of the BG-Sentinel, a new trap for capturing adult Aedes aegypti (Diptera: Culicidae)

In recent years, the development of new tools to gather field information about vector ecological parameters has increased. This report evaluated the BG-Sentinel Trap (BGS-Trap), a promising new attempt to improve collection of the dengue vector, Aedes aegypti. The efficacy of the BGS-Trap was compared with the CDC backpack aspirator, one of the commonest used methods for capturing adult mosquitoes. BGS-Traps captured significantly more Ae. aegypti males (chi2 = 21.774, df = 1, P < 0.05) and females (chi2 = 56.007, df = 1, P < 0.05) than CDC aspirator during all days of field collection. However, CDC aspirator was significantly more efficient to capture Culex quinquefasciatus males (chi2 = 5.681, df = 1, P < 0.05) and females (chi2 = 6.553, df = 1, P < 0.05). BGS-Traps captured host-seeking females (varying between 68.75 to 89.8%) in detriment of females in other behavioral and physiological stages. BGS-Traps proved to be efficient and can be used for monitoring adult mosquito populations.     

Moving beyond biotic homogenization: searching for new insights into vegetation dynamics

Biotic homogenization has been predicted to occur in cities across the world. However, the empirical evidence has been less than convincing. Lososová et al. explore the middle ground between these two points of view in this issue of Journal of Vegetation Science. They take a more sophisticated approach, linking homogenization to bigger questions of vegetation assembly in urban environments.     

The habitat hectares approach to vegetation assessment: An evaluation and suggestions for improvement

Summary The habitat hectares approach is an explicit, quantitative method for assessing the quality of vegetation by adding scores that are assigned to 10 habitat attributes. We believe it will be more repeatable and transparent than other methods that rely on subjective judgement. However, we have four principal criticisms of the method as it is currently proposed: (i) measurement of some of the attributes may be subject to considerable error that varies among assessors; (ii) the comparison of each measure with a single benchmark does not accommodate appropriate disturbance regimes; (iii) the proposed combination of attributes leads to some apparent internal inconsistencies; and (iv) it is not clear how the method will actually be used in practice. We suggest modifications to address these concerns and improve the proposed method. Finally, we make additional suggestions about the method's potential application, including: separate reporting of the extent and quality of different vegetation types to avoid the inappropriate combination of measures of area and quality; valuing appropriate disturbance regimes in natural areas; and considering very carefully the application of compensation or mitigation measures.     

Restoration of vegetation communities of created depressional marshes in Ohio and Colorado (USA): The importance of initial effort for mitigation success

Many studies have attempted to assess the ability of created wetlands to replace the ecological structure and functions of natural wetlands over short time periods (<5 years). Few studies have repeatedly monitored vegetative community development of created depressional wetlands over longer time frames or assessed the return on the level of initial restoration efforts. Here, the vegetation communities of 17 created freshwater marshes in two different geographic regions of the U.S., Ohio and Colorado, ranging from 5 to 19 years old, were monitored over multiple years and compared to natural reference sites. Findings suggest that created marshes in Ohio achieved floristic equivalency with natural reference sites for measures of plant species richness, number of native plant species, number of hydrophytes, and percent plant cover within a decade. Yet, created marshes in Ohio contained double the amount of non-native plant species observed in natural reference sites. In Colorado, created marshes were less successful, failing to achieve floristic equivalency for plant species richness, number of native plant species, and number and percent hydrophytes given more than a decade of restoration. Soil chemistry data suggest that although created marshes achieve certain hydric soil characteristics, they were significantly lower in organic matter, cation exchange capacity, and extractable phosphorus than natural wetlands. Equivalency for soil chemistry will require longer time periods (>14 years). Data suggest that created marshes that seem to be approaching floristic equivalency in early years following construction may level off or even dramatically decline over longer time periods (10–20 years) for certain floristic indicators. Restoration trajectories for Ohio created marshes with strong initial restoration efforts predict floristic equivalency in a median of 14 years compared to 24 years for sites with weak initial efforts. Created marshes with strong initial restoration efforts displayed significantly greater plant species richness, number of native plant species, and number of hydrophytes than sites with low initial efforts, indicating the importance of planting, soil transport and/or contouring in establishing a wetland's restoration trajectory.