Ecology and conservation of an endangered rattlesnake,Sistrurus catenatus,in Missouri,USA

The life history and ecology of the massasauga Sistrurus catenatus, an endangered rattlesnake, was studied from 1979 to 1983 at the Squaw Creek National Wildlife Refuge, Missouri, USA. Except for tail length, this population exhibits little sexual dimorphism. Massasaugas are active from April to October, and are primarily diurnal, except in summer. Snakes are found mainly in a cordgrass prairie in spring and autumn, utilising drier, upland areas in summer. Mean brood size for this population was 6·35, and there was a significant positive relationship between brood size and female body size. Although this species apparently demonstrates considerable geographic variation in reproductive potential, the significance of this variation cannot be currently assessed. Growth rates, estimated from size-frequency data, suggest an age of maturity of 3–4 years for females. Massasaugas at Squaw Creek feed mainly on rodents and other snakes. Current refuge practices, such as controlled burning of the prairie and unrestricted visitor usage, may have significant negative impacts on Sistrurus populations. Recommendations for mitigating these impacts are provided.     

Management of interactions between endangered species using habitat restoration

Commonly used conservation strategies may be insufficient when deleterious interactions between co-habiting endemic species occur. The decline in the population size of the endangered Leon Springs pupfish, Cyprinodon bovinus, in Diamond Y Spring, Texas has been partially attributed to egg-predation by the endangered Pecos gambusia, Gambusia nobilis. This interaction is related to changes in habitat availability; therefore, we aim to manage the conflict via restoration of the breeding habitat. We hypothesized that altering the habitat to expand shallow breeding areas would result in a decrease in the number of gambusia preying on the eggs of spawning pupfish pairs and an increase in the number of males defending territories. In 2 years following the habitat modification, we observed resurgence in the pupfish breeding population and a decrease in egg-predation pressure around spawning pupfish pairs. Additionally, after altering the habitat, gambusia were more dispersed throughout the habitat, as the low numbers of gambusia in a territory were stable regardless of spawning or aggressive behaviors by pupfish. To our knowledge, this is the first empirical example of effective management of deleterious interactions between two endangered species by means of habitat restoration.     

Evaluating the non-consumptive, positive effects of a predator in the persistence of an endangered species

Failure to consider both the consumptive and non-consumptive effects of predators on prey can lead to erroneous conclusions about the net effect of the relationship. The predatory devil crayfish, Cambarus diogenes Girard functions as an ecosystem engineer constructing extensive burrow systems through aquatic habitats. Despite crayfish posing a serious predation threat, preliminary data indicate that the federally endangered Hines Emerald dragonfly larvae, Somatochlora hineana Williamson regularly inhabit crayfish burrows. During late summer, S. hineana larval habitat dries up; leaving crayfish burrows as some of the only wetted habitats. Thus, C. diogenes can affect S. hineana through both direct, negative and indirect positive effects. We examined the positive role of crayfish burrows as drought refuges, and the threat of predation by C. diogenes on S. hineana larvae. Monthly field sampling indicated that S. hineana use open channel areas in spring and early summer moving into burrow systems in mid summer when channel areas normally dry. Laboratory experiments and field observations confirmed that crayfish prey on S. hineana larvae. Adult crayfish were a larger predation threat than juvenile crayfish. Despite their negative predatory impact, removal of crayfish from burrows in the field did not enhance densities of S. hineana larvae. Although S. hineana may face the threat of predation in burrows, they face a greater risk of desiccation if they remain in the open channel. These results lead to the counterintuitive conclusion that the maintenance of a predator is important for conserving an endangered prey species.     

Mulching effects on phosphorus and sulfur concentrations in a Miamian soil in central Ohio,USA

In addition to nitrogen (N), phosphorus (P) and sulfur (S) elements are also essential to conversion of biomass carbon into soil humus. Therefore, soil analyses were done on two long‐term mulching experiments initiated in 1989 and 1996 on a Crosby silt loam (Aeric Ochraqualf or Stagnic Luvisol) soil in central Ohio to assess P and S dynamics in soil for different rates of mulching. Mulch treatments were 0, 8 and 16 Mg ha⁻¹ y⁻¹ without any crop cultivation. Our objectives were to assess: (i) the effect of different mulch rates on P and S concentrations, and soil organic carbon sequestration; (ii) association of available and total P and S with different particle size fractions; and (iii) temporal changes in available and total P and total S concentrations within aggregate and particle size fractions with duration of mulching. Soil samples from 0 to 5 and 5 to 10 cm depths were obtained in November 2000. Mulch rate significantly increased Bray‐P in 0 to 5 and 5 to 10 cm depths but had no significant effect on total P after 4 years of mulching. Total P concentration in the 5 to 10 cm layer increased significantly with mulch application after 11 years, but the total S concentration was not affected. Total P in aggregates>2 mm size at 5 to 10 cm depth was significantly higher than whole soil after 11 years of mulching. More than 50 per cent of the total P was associated with clay fraction, and P concentration increased with duration of mulching. The enrichment factor for total P was in the order: clay>sand>silt. Total S concentration in aggregates increased with increase in aggregate size for both depths, and was in the order: clay>sand>silt. The clay fraction accounted for 48 per cent of total S after 4 years of mulching and 50 per cent after 11 years of mulching. The enrichment factor of S in clay and sand fractions increased with duration of mulching and with depth for clay, and decreased for sand. The C:P and C:S ratios decreased both with duration of mulching and particle size. Availability of P and S is essential for humification of carbon input in crop residue mulch. Copyright © 2004 John Wiley & Sons, Ltd.     

Tillage and land use effects on soil microporosity in Ohio, USA and Kolombangara, Solomon Islands

Micropores are important to soil moisture retention and plant growth. Microporosity and pore size distribution were evaluated using mercury intrusion porosimetery on aggregates from 35-year-old experiments started in 1962 at Wooster (40.5 °N, 82 °W) and South Charleston (39.8 °N, 84 °W) in Ohio, USA and from three land use practices on Kolombangara (8 °S, 157 °E) in Solomon Islands. Tillage treatments in Ohio included: moldboard plowing (MP), chisel plowing (CP), and no-till (NT) with continuous corn. The land use treatments in Kolombangara included: natural forest (NF), traditional farming (TF) and topsoil removal (TR). Pore size measured in aggregates ranged from 0.2 to 100 μm in diameter. Median pore radius was significantly (P < 0.05) larger for NT than for MP and CP treatments at Wooster, but not at South Charleston. Tillage treatments had significant effect on the volume of both storage and residual pores for both sites in Ohio. Volume of storage and residual pores were higher for Wooster than South Charleston soil. At Kolombangara, the NF treatment had significantly larger median and peak pore radii, and microporosity than TF and TR treatments. There was, however, no significant difference among treatments in the volume of pore size distribution. These data support a recommendation for adoption of no-till or conservation tillage in soils of the temperate region, and of minimal disturbance and effective erosion control in soils of the tropics.     

Understanding Tecomella undulata: an endangered pharmaceutically important timber species of hot arid regions

Tecomella undulata (Sm.) Seem. (family Bignoniaceae) is an economically and pharmaceutically important small tree of arid regions of India, Pakistan and Arabia. It is well known as ‘Desert teak’ or ‘Marwar teak’ being the main source of timber amongst the tree species of desert region of Rajasthan, India. T. undulata has occupied a reputed position of having valuable medicinal properties in both folk and classical streams of indigenous medicinal systems. Plant is well-known for its wide range of therapeutic activities like hepatoprotective, antibacterial, antimicrobial, antifungal and anti-termite, immunomodulatory, anticancer, cytotoxic, analgesic, anti-inflammatory, anti-obesity, etc. Rohitakarishta, an ayurvedic drug obtained from T. undulata, is the classical compound which is being prescribed in liver and spleen diseases, oedema and anaemia. This well accepted agroforestry tree of the arid regions is heading towards extinction due to its increasing demand in timber and pharmacological industries coupled with negligible conservation efforts. This species has now been designated as “threatened” in Rajasthan, India. Susceptibility to many pathogens and pests is one of the major problems and detrimental factor in successful establishment and growth of this tree. Conventionally, it is propagated through seeds; however, natural regeneration of plants is poor due to air dispersal of seeds to remote areas, extreme environmental conditions during seed dispersal, improper harvest and storage of seeds, and short seed viability. The tree is very slow growing and suitable vegetative propagation methods are not available for its rapid multiplication. Alternatively, attempts have been made to propagate this tree through in vitro approaches; however, it also has many limitations including difficulties in culture establishment, slow growth, low rooting rates as well as field establishment rates. Moreover, little information is available regarding genetic diversity in this species using morphological and molecular markers. Efforts to undertake breeding programs for improvement of T. undulata have not been initiated yet. Some literature is available regarding cytology, role in agroforestry and silviculture, association with vesicular arbuscular mycorrhiza and application of biotechnological tools in T. undulata, however, an exponential increase in research publications on identification of bioactive constituents and verification of pharmacological effects has been recorded in the recent past. In this communication, we emphasize the research progress made in T. undulata on various aspects and suggest some future directions of research.     

A Modeling Approach to Water Quality Management of an Agriculturally Dominated Watershed, Kansas, USA

Impairment of water quality is a major concern for streams and rivers in the central USA. Total maximum daily loads (TMDLs) establish a watershed framework and set management targets to alleviate pollution from both point and nonpoint sources. For this study, we have used a hydrologic modeling approach to holistically examine the effect of land use management, urban development, and agricultural practices on sediment and nutrient loadings in an agricultural watershed. Annualized Agricultural Nonpoint Source (AnnAGNPS) simulation indicates that while point source dischargers contribute 8% of total nitrogen (TN) and 24% of total phosphorus (TP) loadings to the Marmaton River, agricultural nonpoint sources are the leading pollution source contributing 55% of TN and 49% of TP loading. Based on TMDL analysis and model simulation, 3% of the watershed area (3,244 ha) needs to be targeted to control TN loading whereas 1% of the total area (1,319 ha) is required for TP reduction management. Managing the TN areas alone can achieve a 57% reduction in the TP load required for the TMDL, whereas managing the targeted TP areas can only provide 30% of the required TN reduction. Areas required both TN and TP management comprise 469 ha. Targeting these areas can achieve approximately 22% of the required TN reduction and 29% of the required TP reduction. Overall, 4,094 ha will require management to achieve water quality goals. This study demonstrates that a modeling approach is needed to effectively address TMDL issues and help identify targeted areas for management.     

The paradox of the conservation of an endangered fish species in a Mediterranean region under agricultural intensification

We studied the relative value of natural habitats, river and coastal wetlands, and artificial habitats, irrigation canal and ponds, for the conservation of an endangered fish, Iberian toothcarp, in its southernmost area of distribution, characterised by agricultural intensification. Our results show that the bulk of the population of the Iberian toothcarp is concentrated in irrigation ponds. Natural habitats sustained null or impoverished subpopulations, and individuals showed signs of low metabolic activity. This coincided with the relatively high habitat quality observed in ponds, particularly those with submerged aquatic vegetation, in contrast with the chronic eutrophication of the coastal lagoons. In spite of a generalised aggressive management in the irrigation system, featured by periodic vegetation clearance, desiccation and biocide treatment, the subpopulation of the Iberian toothcarp thrives in it probably thanks to adequate water quality and to an active path dynamics maintained by connectivity through the canal. Agro-environmental measures are discussed for the improvement of this species conservation in natural and artificial habitats.     

Enzyme polymorphism analyses in three endangered species of Himalayan poppy, Meconopsis (Papaveraceae)

Populations of Meconopsis paniculata and M. sinuata inhabit open alpine slopes, while those of M. simplicifolia are restricted to alpine meadows of Sikkim Himalaya. These species are threatened and represented by very small populations. Three enzymes namely acid phosphatase, esterase, and glutamate dehydrogenase were tested for six populations each of M. paniculata and M. simplicifolia and single population of M. sinuata to analyse the genetic diversity of these species. In addition, alkaline phosphatases, glucose 6-phosphate dehydrogenase and malate dehydrogenase were tested for M. paniculata populations. The results on the electrophoretic variations revealed that genetic polymorphism is low to absent in all the populations of the three species of Meconopsis investigated, and the species are characterized by genetic homogeneity with fixed alleles.     

Diversity in tree species in Southeastern Ohio Betula nigra L. Communities

Quantitative data were obtained for arboreal species within 50 lowland forests in southeastern Ohio. Thirty-seven communities were dominated by Betula nigra L. and 13 were dominated by Acer saccharinum L. The acidic soils collected from B. nigra communities contained toxic concentrations of exchangeable Al and low concentrations of Ca and Mg. Tree species diversity (Shannon-Weaver index) and species equitability were inversely related to high concentrations of exchangeable Al and H and directly related to high concentrations of exchangeable Ca and Mg and an increase in soil pH.     

A comparison of terrestrial snail faunas between strip-mined land and relatively undisturbed land in Ohio, USA - an evaluation of recovery potential and changing faunal assemblages

Terrestrial snail surveys were conducted at 1693 ha of reclaimed strip-mined land at The Wilds and at 3344 ha of woodland at the Shawnee Wilderness Area, both in Ohio, USA. These areas shared the same original physiography, vegetative cover, and soils prior to mining and are believed to have had the same land snail assemblages. The Wilds consisted of 37% woods and 63% open fields, both the result of reclamation activities. The Shawnee site was 3% fields and 97% woods. Fifty species were recorded from Shawnee and 60 from The Wilds. The older areas of woodlands and marginal new growth stands in The Wilds had recovered up to 55% of the presumed original woodland fauna based on shared assemblages with Shawnee. The fields at The Wilds were dominated by species that were rare at Shawnee. We hypothesize that these species were adapted to specialized but sparse microhabitats at Shawnee and were able to successfully colonize the disturbed areas (fields) at The Wilds when given the opportunity. As the fields at The Wilds yield to new growth woods these “field” species should return to their lower densities in the woodlands. The ranges of the original woodland species at The Wilds, now confined to the older growth woods, will expand as succession continues. If the woodlands are left to expand, then we expect the majority of the original land snail fauna will eventually return to The Wilds. However, the conversion of original woodlands at The Wilds to open fields during reclamation has complicated and slowed this recovery process. Fifty years after restoration began, The Wilds has not regained its original snail fauna.     

Experimental reintroductions of endangered plant species in their natural habitats in Spain

The large number of Spanish endemic plants and the extent to which they may be endangered are analysed and compared with the equivalent situation in other European countries. The reasons for their threatened status are examined, and the application of different methods of protection is discussed.The protection method used is complementary to the establishment and management of germ-plasm banks and is based on the reintroduction of living material into the areas where the species originally grew. The material for reintroductions is obtained by multiplication of germ-plasm preserved in a seed-bank.This method has been put into practice with several Iberian endangered endemics such as Vella pseudocytisus L., Silene hifacensis Rouy, Hutera rupestris Porta, Antirrhinum charidemi Lange and Artemisia granatensis Boiss. The initial problems faced in the reintroductions and the preliminary results obtained are discussed.     

Effects of ecological restoration on microbial activity,microbial functional diversity,and soil organic matter in mixed-oak forests of southern Ohio,USA

As a result of many decades of fire suppression and atmospheric deposition the deciduous forests of eastern North America have changed significantly in stem density, basal area, tree size-frequency distribution, and community structure. Consequently, soil organic matter quality and quantity, nutrient availability, and microbial activity have likely been altered. This study evaluated the effects of four alternative forest ecosystem restoration strategies on soil microbial activity, microbial functional diversity, soil organic C, and soil N status in two mixed-oak (Quercus spp.) forests in southern Ohio, USA. The soils of these forests were sampled during the fourth growing season after application of (1) prescribed fire, (2) thinning of the understory and midstory to pre-settlement characteristics, (3) the combination of fire and thinning, and (4) an untreated control. Prescribed fire, with or without thinning, resulted in increased bacterial but not fungal activity when assessed using Biolog^®. In contrast, assays of acid phosphatase and phenol oxidase activity indicated greater microbial activity in the thinning treatment than in the other three treatments. Functional diversity of both bacteria and fungi was affected by restoration treatment, with the bacterial and fungal assemblages present in the thin + burn sites and the fungal assemblage present in the thinned sites differing significantly from those of the control and burned sites. Treatments did not result in significant differences in soil organic C content among experimental sites; however, the soil C:N ratio was significantly greater in thinned sites than in sites given the other three treatments. Similarly, there were no significant differences in dissolve inorganic N, dissolved organic N, or microbial biomass N among treatments. Bacterial and fungal functional diversity was altered significantly. Based on Biolog^® utilization treatments the bacterial assemblage in the thin-only treatment appeared to be relatively N-limited and the fungal assemblage relatively C-limited, whereas in the thin + burn treatment this was reversed. Although effects of restoration treatments on soil organic matter and overall microbial activity may not persist through the fourth post-treatment year, effects on microbial functional diversity are persistent.     

Castanea spp. biodiversity conservation: collection and characterization of the genetic diversity of an endangered species

Centuries of co-evolution between Castanea spp. biodiversity and human populations has resulted in the spread of rich and varied chestnut genetic diversity throughout most of the world, especially in mountainous and forested regions. Its plasticity and adaptability to different pedoclimates and the wide genetic variability of the species determined the spread of many different ecotypes and varieties in the wild. Throughout the centuries, man has used, selected and preserved these different genotypes, vegetatively propagating them by grafting, for many applications: fresh consumption, production of flour, animal nutrition, timber production, thereby actively contributing to the maintenance of the natural biodiversity of the species, and providing an excellent example of conservation horticulture. Nonetheless, currently the genetic variability of the species is critically endangered and hundreds of ecotypes and varieties are at risk of being lost due to a number of phytosanitary problems (canker blight, Chryphonectria parasitica; ink disease, Phytophthora spp.; gall wasp, Dryocosmus kuriphilus), and because of the many years of decline and abandonment of chestnut cultivation, which resulted in the loss of the binomial male chestnut. Recently, several research and experimentation programmes have attempted to develop strategies for the conservation of chestnut biodiversity. The purpose of this paper is to give an overview of the status of biodiversity conservation of the species and to present the results of a 7?year project aimed at the individuation and study of genetic diversity and conservation of Castanea spp. germplasm.     

The role of tissue culture in preserving threatened and endangered plant species

The impact of human activities on natural ecosystems has become an issue of growing public concern. While not attenuated by the problems of habitat preservation, human activities in certain regions have caused a depletion of many plant species that might otherwise have remained secure in their respective habitats. Several options are available to address this problem. One which has received only minor attention but has great potential for germplasm preservation is tissue culture. Preliminary work with several species of Pediocactus shows great promise for the application of micropropagative technology.     

Impacts of the loss of neotropical highland forests on the species distribution: a case study using resplendent quetzal an endangered bird species

We evaluated the impacts of land-cover changes of evergreen cloud forests on the distribution of quetzals in the four mountain regions of Chiapas, Mexico. The land-cover changes were estimated comparing satellite images of 1970 and 2000. We also simulated the amount of remnant forests 50 years in the future. The past and the current distributions of quetzals were based on literature records and recent field surveys. Our results showed that in 1970 the forests occupied 973 km², and in 2000, 312 km², and annual loss from 3.34 to 6.85%. Our simulation suggests that 50 years from now, only one region will maintain evergreen cloud forests. In addition, we documented literature reports of 39 forests inhabited by quetzals, but in 2001 there remained 11 small-isolated forests. In order to guarantee the survival of this species, conversation efforts must be made to protect the quetzal and its habitat throughout the entire Mesoamerica region.     

The role of demographic compensation theory in incidental take assessments for endangered species

Many endangered species laws provide exceptions to legislated prohibitions through incidental take provisions as long as take is the result of unintended consequences of an otherwise legal activity. These allowances presumably invoke the theory of demographic compensation, commonly applied to harvested species, by allowing limited harm as long as the probability of the species’ survival or recovery is not reduced appreciably. Demographic compensation requires some density-dependent limits on survival or reproduction in a species’ annual cycle that can be alleviated through incidental take. Using a population model for piping plovers in the Great Plains, we found that when the population is in rapid decline or when there is no density dependence, the probability of quasi-extinction increased linearly with increasing take. However, when the population is near stability and subject to density-dependent survival, there was no relationship between quasi-extinction probability and take rates. We note however, that a brief examination of piping plover demography and annual cycles suggests little room for compensatory capacity. We argue that a population’s capacity for demographic compensation of incidental take should be evaluated when considering incidental allowances because compensation is the only mechanism whereby a population can absorb the negative effects of take without incurring a reduction in the probability of survival in the wild. With many endangered species there is probably little known about density dependence and compensatory capacity. Under these circumstances, using multiple system models (with and without compensation) to predict the population’s response to incidental take and implementing follow-up monitoring to assess species response may be valuable in increasing knowledge and improving future decision making.     

Wild and weedy Lactuca species, their distribution, ecogeography and ecobiology in USA and Canada

During 2002, 2004, 2006 and 2008, trips were undertaken in the United States and Canada by members of the Department of Botany, Palacky University in Olomouc (Czech Republic) to record distributions and sample the diversity of wild and weedy Lactuca species. In that period, 16 states in the USA (Arizona, California, Colorado, Idaho, Iowa, Minnesota, Montana, Nevada, New York, North Carolina, Oregon, South Dakota, Utah, Washington, Wisconsin, Wyoming) and two provinces in Canada (Ontario, Quebec) were visited. Seven wild and weedy Lactuca species (L. serriola, L. saligna, L. virosa, L. canadensis, L. biennis, L. floridana, L. ludoviciana), an interspecific hybrid (L. canadensis?×?L. ludoviciana), and an undetermined Lactuca species were recorded, and 343 seed samples were collected from 200 locations. The largest number of wild Lactuca species that we observed was recorded in Iowa, and the largest number of samples was collected in California. The most common habitats of weedy species (L. serriola, L. saligna and L. virosa) were along transport corridors, such as roadsides, road ditches, parking sites and petrol stations, grassy slopes and ruderal places. The most frequent species was L. serriola, an Old World introduction, which we observed in all states and provinces visited, except for New York, and in broad range of elevations (up to 2,358?m a.s.l.). Lactuca saligna was recorded only one time in Salinas, California. Lactuca virosa was found repeatedly in Washington State along the road to the Mt. St. Helens and in Redwoods, California. Native North American taxa (L. canadensis, L. floridana, L. ludoviciana) were recorded only in Iowa. Lactuca biennis was found only in Canada in the southern part of Quebec. Records of diseases and pests showed only occasional occurrences of downy mildew (Bremia lactucae) and powdery mildew (Golovinomyces cichoracearum). Most plant-disease findings were made in Canada. Results of these efforts enrich our knowledge of the distribution, ecogeography and ecobiology of Lactuca species occurring spontaneously in North America. Seed collections (accessions) will be conserved in the working collection of the genebank at Palacky University to support future research in ecogeography, ecobiology, resistance and genetic polymorphisms, and to enrich of germplasm diversity available for lettuce breeding.     

HPTLC analysis of guggulsterone isomers in Commiphora wightii (Arn.) Bhandari: an endangered oleo-gum resin species heading towards extinction

The oleo-gum resin of Commiphora wightii (Arn.) Bhandari, a pharmacologically important balsamiferous woody shrub, has been used in treating various ailments and disorders since ancient times (2000 B.C.) due to the presence of steroidal compound guggulsterone. Two bioactive isomers of guggulsterone, E and Z, are responsible for lipid- and cholesterol-lowering and anti-cancerous activities. Further, guggul has been approved as food supplement by US-FDA as well as Council of Europe. Indiscriminate harvest of C. wightii from wild with negligible conservation efforts has lead to its inclusion in IUCN assemblage of endangered plant species. For identification of high guggulsterone yielding ecotypes of C. wightii, using high-performance thin-layer chromatographic (HPTLC) analysis, stem samples were collected from 50 plants from eleven locations in arid tracts of Haryana, Gujarat and Rajasthan. Dried, powdered material was subjected to extraction with petroleum ether using soxhlet apparatus. Samples were spotted on precoated activated silica plates (60F-254) and were developed using toluene–acetone (9:1 v/v) as mobile phase. The analysis was carried out in the absorbance mode at 250 nm using HPTLC scanner. The regression analysis data for the calibration plots for E and Z guggulsterone showed good linear relationship with R² = 1 and 0.9897, respectively. Highest concentration of guggulsterone E (284 μg/g dry wt) was found in the accession collected from Palana, Bikaner whereas highest guggulsterone Z concentration (89.5 μg/g dry wt) was found in the accession collected from CAZRI, Jodhpur.