Biodiversity conservation in human-modified landscapes of Mesoamerica: Past, present and future

Mesoamerica provides a unique context for biodiversity conservation in managed landscapes because of its geography, history of human intervention, and present conservation and development initiatives. The long and narrow form of the Mesoamerican landmass, and its division by a central mountain range, has served as both a bridge and a barrier. Conservation efforts in Mesoamerica are unique for the emphasis they place on regional connectivity through the Mesoamerican Biological Corridor and on biodiversity conservation in managed landscapes. The emphasis on conservation in agricultural systems has fostered innovations in payment for ecosystem services, and provides novel insights on the functional role that biodiversity plays in the provisioning of ecosystem services. The increasing rate of economic development in the region and the advent of new payment for ecosystem service schemes have provided new opportunities for forest regeneration and restoration. However, the small scale of private landholdings and the diversity of land uses featured in the region, while contributing to biodiversity conservation due to their structural and floristic complexity, present challenges for biodiversity monitoring and management.     

Differentiation and structure of an Italian landrace of celery (Apium graveolens L.): inferences for on farm conservation

The “Sedano Nero di Trevi” (Black Celery from Trevi) is a landrace grown in Umbria (Italy) at risk of extinction. A morpho-physiological and molecular characterisation of the landrace and a detailed investigation of its cultural and cultivation context were carried out with the aim of facilitating a request for a quality mark, implement in situ (on farm) conservation schemes that are being developed in Italy and register the landrace in the European common catalogue of ‘conservation varieties’. These actions can help the landrace survive. Six farmer populations of the landrace and four élite varieties were characterised for thirteen morpho-physiological traits and nine AFLP primer combinations. The “Sedano Nero” farmer populations were better performers than élite varieties for important agronomic traits, such as yield, under the local agronomic conditions. Both morpho-physiological traits and molecular markers clearly distinguished the landrace from the élite cultivars. In addition, a structure was detected in the landrace with farmer populations being characterised by specific alleles. These results are discussed in connection with the local seed system and possible in situ conservation strategies for landraces.     

Role of informal seed system in promoting landrace diversity and their on-farm conservation: a case study of rice in Indian Himalayas

Role of informal seed system in landrace diversification, in situ conservation on-farm and sustainability in production were investigated as a case study for rice diversity in Indian Himalayas. The diachronic pattern of landrace occurrence revealed substantial increase, both in landrace number and frequency, in time. The local level seed supply in Uttarakhand Himalaya revealed that about 96% seed supply originated from informal system and a mere 4% seed supply is met from formal seed supply networks. In higher elevation ranges, beyond 1200 masl, largely landrace cultivation is practiced and a greater landrace diversification in traditional production was observed. Substantial variations due to environmental adaptations in niche habitats help provide important donor germplasm for crop improvement to users. Further, the population genetic structure also indicated enough diversity being maintained on-farm. Developing pathways for strengthening local level seed system for landrace diversification linked to sustainability in food production and conserving agro-biodiversity has been emphasized.     

European bat lyssaviruses: Distribution, prevalence and implications for conservation

Worldwide, there are more than 1100 species of the Order Chiroptera, 45 of which are present in Europe, and 16 in the UK. Bats are reservoirs of, or can be infected by, several viral diseases, including rabies virus strains (in the Lyssavirus genus). Within this genus are bat variants that have been recorded in Europe; European bat lyssavirus 1 (EBLV-1), European bat lyssavirus 2 (EBLV-2) and, four currently unclassified isolates. Since 1977, 783 cases of EBLVs (by isolation of viral RNA) have been recorded in Europe. EBLV-1 or EBLV-2 has been identified in 12 bat species, with over 95% of EBLV-1 infections identified in Eptesicus serotinus. EBLV-2 is associated with Myotis species (Myotis daubentonii and Myotis dasycneme). A programme of passive surveillance in the United Kingdom between 1987 and 2004 tested 4871 bats for lyssaviruses. Of these, four M. daubentonii (3.57% of submitted M. daubentonii) were positive for EBLV-2. Potential bias in the passive surveillance includes possible over-representation of synanthropic species and regional biases caused by varying bat submission numbers from different parts of the UK. In 2003, active surveillance in the UK began, and has detected an antibody prevalence level of 1-5% of EBLV-2 in M. daubentonii (n = 350), and one bat with antibodies to EBLV-1 in E. serotinus (n = 52). No cases of live lyssavirus infection or lyssavirus viral RNA have been detected through active surveillance. Further research and monitoring regarding prevalence, transmission, pathogenesis and immunity is required to ensure that integrated bat conservation continues throughout Europe, whilst enabling informed policy decision regarding both human and wildlife health issues.     

Conservation and landscape maintenance in Germany: Past,present, and future

Three main sources of landscape maintenance and nature conservation in Germany are identified: the British landscape garden, the official conservation activities, and a private association of nature park promoters. Among their achievements are the German Nature Conservation Act of 1935, the establishment of about fifty nature parks and one national park, a well-developed theory and practice of landscape planning, and three university departments of landscape architecture. The three sources, however, have not yet generated one comprehensive stream of activity, and they seem to lack a common basis of work. To overcome these difficulties, the author proposes a landscape strategy based on a pattern of ecosystems in different successional stages. The strategy is derived from the history of land-use in Central Europe and from the resulting Man-Nature relationships. They created a characteristic landscape pattern defined as the ‘European savanna’, the diversity of which provided for a high degree of ecological stability. The diversity can be maintained even in today's land-use, which consists of four main types. In a given area, one of these types is allowed to prevail, but there is repeated inclusion of the three other use-types in a finely-grained mixture. This should result in a diversified make-up of the landscape, which is both productive and ecologically stable enough to provide for an optimum natural environment of balanced Man-Nature relationships.     

Control of chemical contaminants in foods: past, present, and future

In the late 1930s and early 1940s, almost the only analyses carried out for chemical contaminants in foods were for lead arsenate and other arsenical pesticides in fruits. Since then, a tremendous expansion has occurred in the types of chemical contaminants found in foods and in the activities of the U.S. Food and Drug Administration and other organizations responsible for monitoring and controlling the presence of these contaminants in the food supply. This paper describes the findings and control of additional chemical contaminants in foods, including synthetic pesticides, PCBs (polychlorinated biphenyls), other industrial chemicals, fungal metabolites such as aflatoxins, toxic metals, and radionuclides. The common characteristics of problems connected with these different types of contaminants include uncontrolled entry into the food supply, incidents causing extreme public worry, and near impossibility in removing these contaminants from the food supply. Problems may also arise from new technologies and environmental developments. New approaches beyond ordinary regulatory activities are being used to meet these problems. Broader analytical methods requiring less time and faster and more sophisticated toxicological methods are needed to assess the hazard of these environmental food contaminants.     

Geographical, altitude and agro-ecological differentiation of isozyme and hordein genotypes of landrace barleys from Ethiopia: implications to germplasm conservation

An analysis of the variability of genes encoding six isozyme systems (15 loci) and two storage proteins (2 loci) in landrace barley from Ethiopia is reported. The materials consisted of populations collected from sites as low as 1650 and as high as 3750 meters, covering a wide range of agro-ecological conditions and geographical areas. Of the 17 loci 7 were polymorphic and 10 monomorphic when the 95% criterion of polymorphism was applied. Despite the disproportionate monomorphic loci, polymorphism was detected in all populations when this criterion is used. The populations were found to possess fairly low mean number of alleles per locus (A = 1.5), low mean value of expected heterozygosity (H = 0.134) and a fairly high mean percentage of polymorphic loci (P = 35.3%). The mean F_ST= 0.474 for the populations is typical of inbreeding species. The result indicated that allelic richness is concentrated in altitude class 3 (2500–3000 m) followed by altitude class 1 (<2000 m). Altitude class 2 (2000–2500) holds an intermediate place though it is the highest in terms of expected heterozygosity (H = 0.245). Higher genetic diversity is concentrated in some geographical regions such as Shewa, Arsi, Bale compared to others (Welo, Gamu Gofa, Gojam). Genetic differentiation among the agro-ecological zones was more profound than both among the altitudes and among regions. Correlation analysis between phenotypic diversity (Shannon-Weaver diversity index) and expected heterozygosity (H) for isozyme/hordein loci revealed non significant associations except with respect to agro-ecological zones. In general, it was detected that sites in highland areas in central and northern regions may be more desirable for in situ conservation than sites in peripheral regions in terms of isozyme/hordein diversity and current rate of varietal replacement.     

Landraces in Inland areas of the Basilicata region, Italy: monitoring and perspectives for on farm conservation

A collecting expedition has been carried out in the inland areas of the Basilicata Region, South Italy. Each of the 14 selected municipalities was subdivided in three strata based on the geographical distribution of population and orography: 1. city boundaries, 2. group of country houses, 3. isolated farm houses. Five sites were selected within each stratum/town for a total of 185 sites. In 101 sites crop species germplasm was collected and the farmer-maintainers were interviewed. Altogether 350 accessions were collected, the most common species were Capsicum annuum, Lycopersicon esculentum and Phaseolus vulgaris. A significant number of landraces are still preserved on farm, mostly in isolated farm houses (average age of farmers: 60?years) adopting traditional farming systems but a number of young farmers were also present. Perspectives for on farm conservation and management are discussed and public economic support for “farmer-maintainers” proposed.     

The impact of indigenous soil and water conservation practices on soil productivity: examples from Kenya,Tanzania and Uganda

Farmers in many parts of Africa use indigenous soil and water conserving (ISWC) practices as an integral part of their farming systems. Farmers have developed such methods which have maintained productivity and contributed to long‐term sustainability, while introduced measures have often been rejected or simply failed to achieve their technical objectives. This paper examines the strengths and weaknesses of some ISWC practices in Kenya, Uganda and Tanzania. An evaluation has been carried out based on farmers' evaluation criteria as well as criteria identified by researchers. Farmers' criteria are often based on the quality of their natural resources (farmers are more likely to conserve those soils that will give the highest return on their investment), the resource level of the household (particularly income levels and labour availability), cropping intensity as well as cultural traditions related to age, education and gender. Of great importance, however, is the need to maintain or increase soil productivity. Methods that conserve moisture, reduce soil erosion, maintain soil fertility and increase productivity, which are socially acceptable and economically viable, are those which farmers favour. ISWC practices often have these qualities but farmers have not always been able to adjust the techniques to rapid changes in farming systems and increasing intensity of land use. Soil productivity and economic modelling indicate that although yields declines are lower when traditional technologies are used, long‐term productivity remains a problem. There is an urgent need to work closely with farmers to improve and develop traditional SWC techniques. Copyright © 2000 John Wiley & Sons, Ltd.     

Laconex: A rule-based implementation to advise on plot-level land conservation in Vilathikulam,Southeastern India

Knowledge about land conservation exists along a spatial continuum, represented at the broadest level (with least depth) by international-level experts who have international-level expertise, and at the narrowest level (with most depth) by the individual farmer with the most site-specific knowledge at the plot level. This continuum covers many different aspects of knowledge about land degradation and its amelioration, including technical and cultural knowledge. This paper reports an effort (one in a series of steps) to gather, formalize, codify, and operationalize knowledge about land conservation from two different levels of the continuum. Land conservation knowledge was elicited from farmers and extension agents in Vilathikulam taluk (an area of contiguous villages) in Tamil Nadu, southeastern India, using semi-structured interviews. The knowledge thus gained was combined with knowledge from the literature on soils and land conservation for the area. This information was organized into factual knowledge and process knowledge, and implemented in the form of general recommendations, constraints, and specific recommendations. The process of arriving at these categories was organized into several steps using a spatial anchor and soil type as keys. These were operationalized in a rule-based computer program (LAnd CONservation EXpert -LACONEX), which offers land conservation advice at the plot level for Vilathikulam taluk , using an expert system development environment.     

No-till and conservation agriculture in the United States: An example from the David Brandt farm,Carroll, Ohio

No-till (NT) farming (conservation agriculture) began in the US in the 1960s. The state of Ohio has a university research location that began no-till research in 1962. A few innovative Ohio farmers, including NT pioneers David Brandt and Bill Richards, were early adopters of the new conservation practice. Initially, no-till was most successful on sloping, well drained soils, then with improvements to the system, including cover crops, it became more widely adopted on all soil types. David Brandt was an enthusiastic learner and teacher of no-till practices, working with chemical company representatives and Cooperative Extension Specialists to demonstrate the system.David Brandt's cooperation with Ohio State University researchers continues to provide a valuable site for studying the long term changes in soil health and ecosystem services. Results showed that total microbial biomass as one of the soil biological health indicators significantly increased with an associated decrease in carbon (C) loss under NT compared with conventional tilled soil (CT). Under NT, there was significantly higher total C and total N compared to CT. Active C, as a composite measure of soil health, significantly increased with NT. When cover crops, especially cover crop cocktail mixes, were used, NT substantially improved soil health. Long-term NT with cover crop cocktail mixes significantly increased the soil aggregate stability, compared with CT. The overall rate of C sequestration by NT suggested that the soils on the Brandt farm act as a consistent sink of atmospheric CO2 although this tends to level off after about 20 years. The Brandt farm showed that crop yields are increased under long-term NT with cover crops mixes. Results suggested that starting with a cover crop when switching from CT to NT, is more likely to ensure success and to maintain economic crop yields.Another early adopter, Bill Richards, from Circleville, Ohio, also became a national leader and promoter of no-till farming. He served as head of the United States Department of Agriculture's Natural Resources Conservation Service in the early 1990s and instituted a program that led to rapid expansion of no-till. He advises that farmers who follow conservation agriculture principles need to be more proactive, from local level to national levels, to influence policy decisions that can lead to robust improvement in soil health.     

Tropical forests: Their past,present, and potential future role in the terrestrial carbon budget

In this paper we review results of research to summarize the state-of-knowledge of the past, present, and potential future roles of tropical forests in the global C cycle. In the pre-industrial period (ca. 1850), the flux from changes in tropical land use amounted to a small C source of about 0.06 Pg yr^?1. By 1990, the C source had increased to 1.7 ± 0.5 Pg yr^?1. The C pools in forest vegetation and soils in 1990 was estimated to be 159 Pg and 216 Pg, respectively. No concrete evidence is available for predicting how tropical forest ecosystems are likely to respond to CO₂ enrichment and/or climate change. However, C sources from continuing deforestation are likely to overwhelm any change in C fluxes unless land management efforts become more aggressive. Future changes in land use under a “business as usual” scenario could release 41–77 Pg C over the next 60 yr. Carbon fluxes from losses in tropical forests may be lessened by aggressively pursued agricultural and forestry measures. These measures could reduce the magnitude of the tropical C source by 50 Pg by the year 2050. Policies to mitigate C losses must be multiple and concurrent, including reform of forestry, land tenure, and agricultural policies, forest protection, promotion of on-farm forestry, and establishment of plantations on non-forested lands. Policies should support improved agricultural productivity, especially replacing non-traditional slash-and-burn agriculture with more sustainable and appropriate approaches.     

Crofting and bumblebee conservation: The impact of land management practices on bumblebee populations in northwest Scotland

The northwest of Scotland is a stronghold for two of the UK’s rarest bumblebee species, Bombus distinguendus and Bombus muscorum. The predominant form of agricultural land management in this region is crofting, a system specific to Scotland in which small agricultural units (crofts) operate rotational cropping and grazing regimes. Crofting is considered to be beneficial to a wide range of flora and fauna. However, currently there is a lack of quantitative evidence to support this view with regard to bumblebee populations. In this study we assessed the effect of land management on the abundance of foraging bumblebees and the availability of bumblebee forage plants across crofts in northwest Scotland. The results of our study show that current crofting practices do not support high densities of foraging bumblebees. Traditional crofting practice was to move livestock to uplands in the summer, but this has been largely abandoned. Summer sheep grazing of lowland pasture had a strong negative impact on bumblebee abundance and forage plant availability throughout the survey period. The use of specific ‘bird and bee’ conservation seed mixes appears to improve forage availability within the crofted landscape, although the number of bees observed remained low. Of the forage plants available, the three most frequently visited species were from the Fabaceae. We therefore conclude that the creation of agri-environment schemes which promote the use of Fabaceae-rich seed mixes and encourage the removal of sheep grazing on lowland areas throughout the summer are essential in order to conserve bumblebee populations within crofted areas.     

The impact of reed management on wildlife: A meta-analytical review of European studies

We reviewed European studies on the effect of reed management (harvesting, burning, mowing and grazing) on reedbed wildlife, and in addition, on the performance of re-growing reed (Phragmites australis). Our database consisted of 21 studies conducted on 10 plant species, 17 taxonomic groups of invertebrates and 11 bird species, and published between 1982 and 2006.We found that reed management modifies the structure of re-growing reed stands: reed stems were shorter and denser in managed sites than in unmanaged sites. However, harvesting does not have an impact on aboveground biomass. Plant species richness increased by 90% in managed stands in fresh water marshes, but not in saline water marshes.Overall, reed management had a significant negative impact on invertebrate community, but the duration of management was an important factor determining the magnitude of the effect. Short-term management (1-2 years) had no effect on invertebrates, whereas management for longer period significantly reduced invertebrate abundance. Reed harvesting and burning reduced abundance of passerine birds by about 60%. This was probably associated with food limitation as the numbers of butterflies, beetles and some spiders were reduced. Therefore, the optimal reed management regime to preserve number of birds and invertebrates in reedbeds could be a rotation of short-term management (1-2 years). However, the optimal interval between management applications should be established in future studies.     

Effect of seed rate and nitrogen fertilizer on weed species composition,density and diversity in two sesame varieties

To evaluate the effect of seed and nitrogen rates on weed species composition, density, biomass and diversity in two sesame (Sesamum indicum L.) varieties, a field experiment was conducted in 2009, 2010 and 2011 rainy seasons at Samaru, Nigeria. Four seed rates, 2, 4, 6 and 8 kg ha^?1, four nitrogen rates, 0, 30, 60 and 90 kg N ha^?1 and two sesame varieties NCRIBEN 01M and E8 were arranged as factorial in a split plot design. Weeds with the highest important values in sesame field were Dactyloctenium aegyptium, Ludwigia decurrens, Ageratum conyzoides and Cyperus esculentus. Year had a significant effect on weed density, biomass, diversity, evenness and richness. Weed density, biomass, diversity and richness were lowest in the 2011 trial and weed species evenness in 2009. Variety E8 reduced weed biomass better than NCRIBEN 01M. Averaged over years, weed diversity and evenness were lowest at 4 kg seeds ha^?1. Seed × nitrogen rates effect of 4 kg seed ha^?1 and 30 kg N ha^?1 produced the lowest weed species diversity and evenness. The result suggests that variety E8 at 4 kg seed ha^?1 and 30 kg N ha^?1 with hoe weeding at 3 and 6 WAS may provide better weed control, and it is recommended in sesame production.     

The impact of fossils on the Evolutionary Distinctiveness and conservation status of the Australian lungfish

The recognition of phylogenetic information for evaluating conservation priorities has stressed the importance of basal taxa. The “Evolutionary Distinctiveness” index (ED) is a species-specific index that includes branch length expressed as an absolute value measured in millions of years that can be applied to a single terminal taxon in a phylogeny. The ED depends on the tree pattern, i.e. of a cladogram included into a time-scale. When calculated for the Australian lungfish (Neoceratodusforsteri), a threatened dipnoan that occurs naturally only in southeast Queensland, the ED index shows variable value according to the chosen tree. On the basis of a recently proposed phylogeny including a new fossil find from the Early Cretaceous of Thailand, the ED value reaches the highest value for piscine sarcopterygians, and for all vertebrates, and thus reinforces the “originality” of this fish. This example points out the importance of fossils in the resolution of phylogenies and beyond, in the calculation of indexes supporting conservation decisions.     

The characterization of Nigerian varieties of pepper, Capsicum annuum and Capsicum frutescens by SDS- polyacrylamide gel electrophoresis of seed proteins

The possibility of using electrophoresis to characterize varieties of pepper, Capsicum annuum and Capsicum frutescens cultivated in Nigeria was investigated. The SDS- polyacrylamide gel electropherogram of extracted total seed proteins of 10 breeding lines in each of the 6 varieties investigated, revealed a pattern in which 12 polypeptide bands with apparent molecular weight range of 22 to 98 kilodaltons could be distinguished. The result showed that the six varieties could be characterized on the basis of presence/absence and staining intensities of 7 polypeptide bands. It is suggested that SDS- polyacrylamide gel electrophoresis of seed proteins provides a useful analytical technique for the characterization of varieties of pepper and there may be genotype duplicates in the collection of Nigerian Capsicum germplasm.     

The role of ants in conservation monitoring: If, when, and how

Ants are increasingly being recognized as useful tools for land managers to monitor ecosystem conditions. However, despite an abundance of studies on ant responses to both environmental disturbance and land management techniques, an analysis of the practice and value of including ants in monitoring is lacking. Consequently, conservation managers are left with little guidance as to if, when, and how ants can be used to assess conservation activities. Based on our review of approximately 60 published studies, we outline five areas where ants provide valuable information for management-based monitoring: (1) to detect the presence of invasive species, (2) to detect trends among threatened or endangered species, (3) to detect trends among keystone species, (4) to evaluate land management actions, and (5) to assess long-term ecosystem changes. We also discuss practical considerations when designing a monitoring framework for ants, including appropriate methods, taxonomic resolution for sampling, and spatial and temporal scale. We find that when integrated with management goals, monitoring ants can provide information over the short-term on topics such as the status of invasive or keystone species, as well as over longer time frames, for instance the impact of climate change. Overall, we conclude that ants merit monitoring based on their inherent ecological qualities, independent of any “indicator” attributes they might have.