Domestic Grazing Research Articles

Experimental study on survival rates in two arboreal species from the Argentinean Dry Chaco

Given the state of resource degradation encountered in Chaco (Argentina), research on forest recovery methods and management proposals in accordance with the socioeconomic conditions of the region's inhabitants are imperative. The evaluation of factors that affect the plantation of arboreal species and the management knowledge necessary in the initial afforestation of highly degraded production systems are important elements in the plan for recovery. The present study investigates the importance of the factors: the effect of shrubs, grazing and native species to be planted on the success of afforestation in areas characterized by a high degree of resource degradation. Its objectives are to evaluate the role of Larrea divaricata ‘jarilla’ in the survival of Prosopis chilensis (Mol.) Stuntz and Aspidosperma quebracho blanco, and the effects of attenuated levels of domestic grazing on the survival rate of P. chilensis afforestation in real production units. Four areas located in old beds left by the Chancaní River, reflecting the degraded soil and forest conditions, were set up as real production units. The vegetation community at each site contained 70% L. divaricata, the dominant species. Prosopis flexuosa D.C. and emergent A. quebracho blanco (quebracho) comprised the arboreal stratum. Experimentally planted quebracho and mesquite seedlings' survival rates differed with respect to the shrub-effect. Shrubs were not found to exert any facilitating effect on the survival rate in mesquite, indicating that mesquite would have a higher survival rate in open spaces. However, shrub presence was found to be somewhat beneficial to survival in quebracho one year after the beginning of the trial. Herbivores with and without shrubs were a significant factor decreasing survival in P. chilensis.

Precipitation Chemistry in the Sahelian Savanna of Niger, Africa

Within the framework of the IDAF (IGAC DEBITS AFRICA) network, we present in this paper data on precipitation and aerosol chemistry in the semiarid savanna of the Sahelian region of Niger. An automatic wet-only precipitation collector was operated at the Banizoumbou station during the entire 1996 rainy season (June to September 1996). Inorganic (Na+, NH4+, K+, Mg2+, Ca2+, Cl-, NO3-, SO42-) and organic contents of the precipitation (HCOOH, CH3COOH, C2H5COOH) were determined by Ion Chromatography (IC) in 29 rainfall events. Once per week, bulk particle samples were collected on the same site, and soluble water material was determined by IC. We examined the influence of atmospheric gas and particle sources on the precipitation and aerosol chemical contents. We established the influence of marine, terrigenous, and biogenic sources in the Sahelian region. The terrigenous signature is dominant and related to Sahelian soil erosion, with a high calcium content in precipitation (31.2 μeq L-1) and in aerosols (1.8 μg m-3). Two other signatures of atmospheric sources are highlighted by the relatively high nitrogenous (ammonium and nitrate) and organic contents (formate, acetate) in the precipitation. Ammonium (12.9 μeq L-1) and nitrate (12.3 μeq L-1) contents confirm respectively the biogenic source of ammonia released by domestic animal excreta in Niger and the natural emissions from semiarid savannas soils, perturbed by wild or domestic animal grazing. In spite of a high potential acidity given by nitrate, formate and acetate; a weak acidity (H+ (2.1 μeq L-1) is calculated from the mean pH of 5.67 measured. A statistical analysis of the aerosol chemical composition clearly indicates that nitrates are strongly correlated at the 1% level with terrigenous ions, i.e., Ca2+ and Mg2+ (0.95 < r < 1). We observed a similar relationship between all the terrigenous ions and nitrate in the precipitation. In the Sahelian region, alkaline soil dust representative of the terrigenous contribution interact, with gaseous nitrogenous and carbonaceous compounds, leading to the neutralization of acid gases and subsequent weak acidity in precipitation. Finally, taking into account the main chemical characteristics of Banizoumbou precipitations and aerosols, which demonstrate the importance of heterogeneous and multiphase chemical processes, we propose a conceptual model of the atmospheric chemistry in the Sahelian region.

Demographic Evaluation of a Herbivory-Sensitive Perennial Bunchgrass: Does It Possess an Achilles Heel?

Plant and tiller demography of a C 4 perennial bunchgrass, Eriochloa sericea, were evaluated to define specific traits that contribute to its sensitivity to herbivory by domestic grazers. We tested three hypotheses: (1) defoliation adversely impacts tiller recruitment to a greater extent than mortality, (2) tiller recruitment and/or mortality are particularly sensitive to defoliation at the time of culm elongation, and (3) synchronous tiller recruitment contributes to a meristematic limitation which constrains growth following defoliation. Demographic variables were monitored on permanently marked plants and tillers that were defoliated at various frequencies and stages of phenological development for two successive years. Hypotheses one and three were rejected because defoliation adversely impacted per capita tiller mortality to a greater extent than per capita tiller recruitment and tiller recruitment occurred throughout the spring and summer, rather than synchronously. Apical meristem elevation in vegetative tillers did not extend beyond 5 mm above the soil surface and the proportion of reproductive tillers did not exceed 10% of the total number of tillers. Low values for both morphological attributes indicate that they did not contribute to a meristematic limitation constraining leaf growth. Hypothesis two was not rejected because cumulative, but not per capita, tiller recruitment was reduced to a greater extent by defoliation during culm elongation than during the pre-culm or post-culm stage. Plants that received multiple defoliations exhibited the greatest decline in basal area and tiller number compared to undefoliated plants, and only the undefoliated plants and plants defoliated during the pre-culm stage recruited a sufficient number of tillers to offset tiller mortality. In spite of the adverse effects of two of the four defoliation regimes, we were unable to identify a specific trait (i.e., Achilles heel) within this species that contributed to a meristematic limitation and herbivory-sensitivity. An alternative interpretation of herbivory-sensitivity is proposed which emphasizes the involvement of more subtle extrinsic mechanisms, including herbivore-mediated competitive interactions and drought-herbivory interactions. Assessment of herbivory resistance based on the 'specific trait approach' fails to recognize and address the importance of extrinsic mechanisms associated with herbivore-induced processes at higher ecological scales.

Cheatgrass ( Bromus tectorum L) dominance in the Great Basin Desert : History, persistence, and influences to human activities

Cheatgrass ( Bromus tectorum L), an exotic annual, is a common, and often dominant, species in both the shadscale and sagebrush-steppe communities of the Great Basin Desert. Approximately 20% of the sagebrush-steppe vegetation zone is dominated by cheatgrass to the point where the establishment of native perennial species is nearly Impossible. This paper discusses the historical factors that led to the establishment and dissemination of cheatgrass in the Great Basin, examines the processes that further cheatgrass dominance, provides examples of subsequent influences of the grass to human activities, and links the ecological history with range condition models. Evidence suggests that cheatgrass was introduced accidentally to the Great Basin as a grain contaminant at the end of the 19th century at the same time that largescale domestic grazing was occurring. Imported from Mediterranean Europe and central and south-western Asia, seeds of cheatgrass exploited an ecological niche, as no native annual was dominant in the Great Basin. Cattle, sheep, and feral horses facilitated establishment, for they spread the seeds in the same areas that they disturbed. Once established, cheatgrass promoted the likelihood of fire to the detriment of the native species. in addition, other factors, such as the effects of the lack of vesicular arbuscular mycorrhizae and selective lagomorph grazing have worked in concert to further establish cheatgrass dominance. The ecological consequences of cheatgrass establishment have been an increase in fire frequency and intensity, a decrease in species diversity, and a landscape susceptible to severe erosion. Bunchgrasses interspersed with longlived perennial shrubs now are replaced with either nearly pure patches of cheatgrass or swaths of cheatgrass and shortlived perennial shrubs. Some consequences to human activities involve the numerous ramifications of rangeland fires with costs of approximately US$20 million annually, the undependability of cheatgrass as a source of forage for cattle and sheep, and the value of biotic diversity as numerous plant and animals species undergo high amplitude population fluctuations. Management of these Great Basin vegetation communities should be approached using the state and threshold range condition model.

Comparison of a common, rare and declining plant species in the Asteraceae: possible causes of rarity

Three forbs of contrasting abundance were compared with the aim of identifying ecological traits that may be associated with differences in abundance in Australia. Hypochoeris radicata (an extremely common, exotic species), Cymbonotus lawsonianus (rare in some regions, moderately common in others) and Microseris lanceolata (once widespread but which has dramatically declined) are all species of grasslands and grassy woodlands. Habitat details and phenological observations are reported from the New England Tablelands, New South Wales where the three species co-occur. This information is synthesized with that available in the literature. Part of the success of H. radicata relates to its broad environmental tolerance. Although C. lawsonianus and M. lanceolata are both widely distributed in Australia, the range of habitats in which they occur is more limited. The depletion of M. lanceolata populations is largely attributed to a vulnerability to domestic grazing animals that may be linked to its palatability and architecture. The more common C. lawsonianus and H. radicata appear more tolerant of grazing and mowing and may be advantaged by their ability to form flat rosettes. Despite its occurrence at sites with soil disturbance, C. lawsonianus is still rare in comparison with H. radicata. It may be restricted by a lack of phenotypic plasticity that prevents plants adopting an erect leaf position under more competitive situations. A number of rare native herbs appear to be disturbance-dependent, and it is suggested that C. lawsonianus may share with them highly specific ecological requirements that make both undisturbed and human-disturbed sites sub-optimal for their persistence.

Species Interactions in a Successional Grassland. III. Effects of Canopy Gaps, Gopher Mounds and Grazing on Colonization

SUMMARY (1) In a perennial grassland undergoing succession after the removal of domestic grazers, three natural processes could disrupt the canopy, and thus affect colonization. These are: canopy gap formation due to the death of individual bunchgrasses; soil disturbance by gophers; and grazing by native animals. (2) Species' abilities to colonize canopy gaps and gopher mounds were assessed in the field, with seed introduction experiments, for the five most cover-dominant grass species: Anthoxanthum odoratum, Holcus lanatus, Deschampsia holciformis, Rytidosperma pilosum (all perennial bunchgrasses) and Vulpia bromoides (an annual grass). (3) The effects of native grazers on colonization by the most abundant species, Anthoxanthum, were assessed, using grazer exclosures and seed introductions in annualdominated vegetation, where grazing activity was highest. (4) Colonization success was quantified as total leaf area, number of survivors and seed production, in sites where seeds of the colonist either fell naturally, or were introduced at natural densities. (5) The formation of canopy gaps by the death of individual bunchgrasses and soil disturbances by gophers strongly affected colonization success. The best colonizers were Anthoxanthum and Holcus, whose colonization success was increased 6-2500-fold by canopy gap formation, and 10-200-fold by the formation of gopher mounds. Few, small seedlings of Deschampsia and Rytidosperma survived in canopy gaps or on gopher mounds. Unlike Anthoxanthum and Holcus, Deschampsia and Rytidosperma did not reproduce in gaps or on mounds over a two-year period. (6) Vulpia colonists had higher seed production on mounds than the four perennials. Vulpia also colonized canopy gaps, but was excluded by perennial vegetation in the second year of growth in the gaps. (7) In annual-dominated vegetation, neither aboveground biomass nor colonization by Anthoxanthum was affected by excluding grazers. However, exclusion of grazers led to an increase in the cover of forbs after two years. Clipping aboveground vegetation allowed Rytidosperma to achieve dominance in sites where, under undisturbed conditions, it existed only as a suppressed understorey. All other perennials were negatively affected by clipping. (8) The species with the highest natural densities of seed rain also had the greatest perseed colonization success, even though negative density-dependent effects must have been

Konza Prairie Research Natural Area of Kansas State University

Konza Prairie Research Natural Area (KPRNA) is an 8616 acre (3487 ha) tract consisting mostly of native tallgrass prairie, and is located in southern Riley county in the Flint Hills of eastern Kansas. Following the leadership of L. C. Hulbert, The Nature Conservancy (TNC), with money provided by Katharine Ordway, set aside KPRNA during the period 1971 to 1979. Under ownership and lease agreements between TNC and Kansas State University, the site is managed for research by the Division of Biology. Research activity has been increasing steadily on KPRNA since 1977 when it was set aside for ecosystem research. The core of the management involves experimental manipulation of watersheds with controlled fire (several replicated intervals between fire from 1 to 10 years plus unburned references) and with native and domestic grazers (planned reintroduction of bison and cattle to different treatment watersheds in November 1987) (Hulbert, 1985). The tallgrass prairie ecosystem once covered about 7% of the U.S., i.e., most of the Midwest (Kiichler, 1964). In most states where the type dominated the presettlement landscape (Illinois, Iowa, Indiana, southern Wisconsin, southern Minnesota, northern Missouri, eastern Nebraska, eastern North Dakota and eastern South Dakota) the soils have been plowed and converted to grain production agriculture, among the most productive agricultural areas in the world. Not much unplowed prairie is left and the opportunity for watershed level work under unplowed conditions does not exist at any other tallgrass prairie site in the United States. The National Science Foundation included KPRNA in its network of sites dedicated to long-term ecological research (LTER). That research has been underway since late 1980. Kings Creek, a central tract of 2619 acres (1060 ha) on KPRNA, was added to the U.S. Geological Survey's network of benchmark watersheds in 1979 (Biesecker and Leifeste, 1975) and the drainage area has been identified as a fixed station in the Survey's pilot research program termed National Water Quality Assessment (NAWQA) (Stamer, pers. comm.).

Salt marshes of Atlantic Canada: their ecology and distribution

This paper reviews the status of research on the Atlantic salt marshes of eastern Canada. The floristics, habitats, and biophysical aspects of the Atlantic salt marshes are described and aspects relating to anthropogenic influences on the Atlantic marshes are discussed in the context of contemporary rural settlement and vulnerability to offshore oil development. Guidelines for environment management, protection, and rehabilitation research are proposed. Such guidelines are deemed important since more than half the 33 000 ha of salt marshes in Nova Scotia have been dyked for agriculture. Most of the salt-marsh habitats in Newfoundland have a high degree of domestic grazing, even though the marshes are small in size and rare in occurrence. The least disturbed in terms of domestic use are the Labrador salt marshes which, although grazed by migratory ducks and geese, have not yet been influenced by man's activities. In addition, the Labrador salt marshes are discussed and compared with the northern marshes of arctic Canada in terms of their ecology and formation.

Short-lived phosphorescent components in CsI(T1) scintillation crystals

Cheatgrass (Bromus tectorum L), an exotic annual, is a common, and often dominant, species in both the shadscale and sagebrush-steppe communities of the Great Basin Desert. Approximately 20% of the sagebrush-steppe vegetation zone is dominated by cheatgrass to the point where the establishment of native perennial species is nearly Impossible. This paper discusses the historical factors that led to the establishment and dissemination of cheatgrass in the Great Basin, examines the processes that further cheatgrass dominance, provides examples of subsequent influences of the grass to human activities, and links the ecological history with range condition models.Evidence suggests that cheatgrass was introduced accidentally to the Great Basin as a grain contaminant at the end of the 19th century at the same time that largescale domestic grazing was occurring. Imported from Mediterranean Europe and central and south-western Asia, seeds of cheatgrass exploited an ecological niche, as no native annual was dominant in the Great Basin. Cattle, sheep, and feral horses facilitated establishment, for they spread the seeds in the same areas that they disturbed. Once established, cheatgrass promoted the likelihood of fire to the detriment of the native species. in addition, other factors, such as the effects of the lack of vesicular arbuscular mycorrhizae and selective lagomorph grazing have worked in concert to further establish cheatgrass dominance.The ecological consequences of cheatgrass establishment have been an increase in fire frequency and intensity, a decrease in species diversity, and a landscape susceptible to severe erosion. Bunchgrasses interspersed with longlived perennial shrubs now are replaced with either nearly pure patches of cheatgrass or swaths of cheatgrass and shortlived perennial shrubs. Some consequences to human activities involve the numerous ramifications of rangeland fires with costs of approximately US$20 million annually, the undependability of cheatgrass as a source of forage for cattle and sheep, and the value of biotic diversity as numerous plant and animals species undergo high amplitude population fluctuations. Management of these Great Basin vegetation communities should be approached using the state and threshold range condition model.

The status and conservation of forest wildlife in Himachal Pradesh, Western Himalayas

We report on wildlife and habitat surveys carried out by the Himachal Wildlife Project over two years in the upper Ravi, Beas and Sutlej catchments of Himachal Pradesh, Western Himalayas. Efforts were concentrated in the upper Beas area where natural forest ecosystems are most extensive. The wildlife of temperate forest ecosystems in the Western Himalayas is threatened by destruction of habitat and hunting. Two species of pheasants occurring in the survey area are listed in the IUCN Red Data Book (1979). We located small populations of both species and obtained information on their habitat requirements. The status of most large mammal species appears to be precarious, with the populations we encountered being small and fragmented. Species formerly common but now rare include Himalayan brown bear, Himalayan tahr, Himalayan ibex, and musk deer. The snow leopard has disappeared completely from the area. The main causes of habitat destruction are domestic grazing, timber extraction, road construction, and extension of temperate agriculture. Adequate protection from illegal hunting is urgently required. We identified an area of relatively undisturbed natural forest in Inner Seraj, Kulu District, as the most promising place for the establishment of a National Park or Biosphere Reserve.

Biomass and Forage Production from Reclaimed Stripmined Land and Adjoining Native Range in Central Wyoming

Aboveground biomas and forage production from native range and adjacent reclaimed stripmined land were measured in 1977. On 2 of the 4 native range transects the aboveground biomass was greater than on reclaimed areas, largely due to big sagebrush and mat-forming species. Forage production, def’ined IS the vegetation consumed by domestic grazing animals on properly grazed range, was equal to or greater on the reclaimed land than on adjoining native range. Reclamation of stripmined lands is required by both the Wyoming Department of Environmental Quality and by recently (1977) enacted federal legislation. In both instances “production”of vegetation equal to, or greater than, that of the pre-mined condition is one of the requirements of the laws and regulations promulgated by the enforcement agencies. Interpretation of the term production is variable. To some it means total aboveground biomass regardless of whether or not it is usuable by grazinganirnals,and to othersit carries the connotation of “forage” that can be utilized. During the summer of 1977 a study was initiated near Glenrock, Wyo., to compare biomass and “forage” production from undisturbed native range with that from adjacent lands which had been reclaimed after stripmining for coal production. Description of the Area The study area lies near the southern edge of the Powder River Basin. The native range is quite variable with some areas supporting almost pure stands of herbaceous species and others with variable stands of shrubs (primarily big sagebrush, Artemisia tridentata) and succulents or mat-forming species such as plains pricklypear (Opuntiapolyacantha) and hooker sandwort (Arenaria hookeri). The most common vegetation type is sagebrush-grass and this type was selected for sampling to determine aboveground biomass and “forage” production. In accordance with Wyoming laws, rules, and regulations, the topsoil is removed from the land prior to mining and is then spread over reshaped soil and seeded to reclaim the land to its previous major use, which in this study was for grazing of domestic livestock. After the mining operation has progressed for a few years, there is a new acreage of mined-out land to be reclaimed each year. Sometimes the land to be reclaimed is ready for seeding in the fall and at other times it is not ready for seeding until spring. Four areas of reclaimed land were sampled in this study. Area A was seeded in the spring of 1973 with a mixture of 9 lb of Fairway crested wheatgrass (Agropyron cristatum). 3 lb of western wheatgrass (Agropyron smithii), and 3 lb of thickspike wheatgrass (Agropyron dasystachyum) per acre. Five growing seasons had Author is Professor Emeritus Division of Range Management, College of Agricultore, University of Wyoming, Laramie 82071 Manuscript received December I I, 1980. elapsed prior to sampling. Areas B, C, and D were all seeded with 6 lb of Fairway crested wheatgrass, 6 lb of Nordan crested wheatgrass (Agropyron desertorum) and 3 lb each of western wheatgrass and thickspike wheatgrass per acre. From these figures it may be noted that the 1973 seeding was 60% and the 1975 seedings were 67% introduced species. Areas B and C were seeded in the fall of 1975 and only 2 growing seasons had elapsed prior to sampling. Area D was seeded in the spring of 1974, thus having completed 3 growing seasons prior to sampling.

Effects of Burning on the Algal Communities of a High Desert Soil near Wallsburg, Utah

Effects of Burning on the Algal Communities of a High Desert Soil near Wallsburg, Utah

Recovery of Cryptogamic Soil Crusts from Grazing on Utah Winter Ranges

Range exclosures located throughout Utah in cool desert shrub communities were analyzed to determine, (1) response of cryptogamic crusts to grazing, (2) soil variables that influence development of cryptogamic crusts and (3) time needed for reestablishment of cryptogamic communities after disturbance. The amount of lichen, moss and algal cover was found to be considerably reduced by domestic grazing. Sites with moderate to high as opposed to light cryptogamic cover were characterized by significantly heavier textured soils and greater salinity. Cryptogamic cover increased from 4% to 15% during first 14-18 years of exclusion from grazing, but increased only 1% during next 20 years. Reestablishment of a cryptogamic occurs in at least 14-18 years and possibly sooner. Until recently little attention has been given soil stabilizing role of nonvascular plants (cryptogams). Studies in semidesert regions of Utah in past decade have made it increasingly clear that such plants (particularly lichens, mosses and algae) exert a significant impact on soil stability and rates of water infiltration (Anderson et al., 1982; Kleiner and Harper 1972; Kleiner and Harper 1977; Loope and Gifford 1972). The control of wind erosion is of primary importance in arid West. Many desert ranges are sparsely vegetated, resulting in large amounts of exposed soil surface. Brady (1974) suggested the presence of a stable soil crust or a rough soil surface decreased severity of wind erosion. Cryptogamic soil crusts have such a double protective influence at soil surface, since they cement soil fragments into cohesive units and produce roughened surfaces. Filamentous blue-green algae associated with soil crusts produce thick gelatinous sheaths (Durrell and Shields 1961) that render them more tolerant to desiccating conditions of desert (Fig. 1). These gelatinous sheaths coupled with intertwinning growth habit of algal filaments effectively bind surface soil particles, forming a distinct felt-like surface or shallow subsurface meshwork on many desert soils. Moss and lichen constituents of cryptogamic crusts are also important soil stabilizers. Thalli of these plants often cover much of soil surface and small ventral rhizoids penetrate surface in much same way that algal filaments do. Lichens and mosses thus become anchored on soil surface and shield soil from erosive winds and rain. The irregular soil surface caused by algal growth and lichen and/or moss thalli (Fig. 2) breaks up micro-patterns of wind flow, reduces windborne soil losses and traps drifting soil particles. The stabilizing effect of cryptogamic crusts as described here lacks quantitative analysis, thus our conclusions are based on personal Authors are, respectively, senior staff ecologist, Native Plants, Inc., Salt Lake City, Utah 84108, professor, and associate professor, botany and range science, Brigham Young University, Provo, Utah 84602. Research supported by a grant from Intermountain Forest and Range Experiment Station under a cooperative agreement supplement to 12-1 1-204-31. The collaboration of Ralph C. Homgren ofthe IFRES is gratefully acknowledged. Manuscript received June 2, 1979. Fig. 1. This filamentous blue-green alga is a common constituent of cryptogamic soil crusts. Note unusually thick sheath. experience and observations of others (Anantani and Marathe 1974, Durrell and Shields 1961, Fletcher and Martin 1948, Kleiner and Harper 1972, Kleinerand Harper 1977, Singh 1950). However, there is little question that cryptogamic communities are of importance in stabilization of many arid regions of western North American. Wind erosion on arid ranges is probably intensified by grazing during dry periods. Although hooved grazing animals are destructive to highly developed cryptogamic soils crusts, it seems possible that grazing programs can be developed that minimize damage to Fig. 2. The pinnacling of soil surface seen here isa common characteristic of more highly developed cryptogamic soil crusts. JOURNAL OF RANGE MANAGEMENT 35(3), May 1982 355 This content downloaded from 207.46.13.86 on Fri, 14 Oct 2016 04:20:13 UTC All use subject to http://about.jstor.org/terms

Fire in Pastoral Areas of Poplar Box (Eucalyptus Populnea) Lands.

Fire has been present during the evolution of poplar box communities and the flora is well adapted to fire. Broad fire regions are recognised on the basis of bioclimatic data and the effects of different fire regimcs on plant species and communities arc dis- cussed in relation to these regions. Grazing combined with the variable rainfall makes the accurate prediction of vegetation changes resulting from fire difficult. Fire is currently episodically associated with over-average rainfall in most areas as the predominant fuel is grass. Minimum fuel quantities of 100 g m-2 in pastures where fuel is continuous and 150 g m-' in pastures with discrete tussocks are required to carry a fire. Fire can drastically reduce shrub numbers, especially juvenile and seedling plants in the short term, but attitudes about using fire for shrub reduction vary from region to region according to the likelihood of growth or replacement pastures. Grazing control after burning to permit the recovery of the ground layer is difficult because of grazing by native herbivores. There is a need for further studies on fire behaviour and plant survivorship characteristics as affected by climate and native and domestic animal grazing.

An ecological survey of the Royal Karnali-Bardia Wildlife Reserve, Nepal: Part III: Ungulate populations

Population density and biomass estimates for wild and domestic ungulates in the Royal Karnali-Bardia Wildlife Reserve, Nepal, are presented and compared with values obtained from other reserves in South Asia. Wild ungulate population densities varied in relation to habitat diversity; large herbivores were most numerous where early and intermediate successional stages intergraded with one another and only sparsely distributed in continuous climax sal Shorea robusta forest. Chital Axis axis was the most abundant wild ruminant in the reserve. It and the nilgai Boselaphus trago-camelus constituted 88% of the total wild herbivore biomass in the southwestern corner of Karnali-Bardia, where an intensive study was carried out. The biomass of domestic stock utilising the same study area in 1975 was computed to be 15–17 times higher than the levels attained by wild ungulates in April of 1977, nearly two years after the reserve borders had been closed to domestic grazing. Observations during the hot-dry season indicated that both wild and domestic ruminants competed for the same forage species. Among the wild ungulates, chital were decidedly the most gregarious, commonly associating in feeding aggregations of over 20 individuals on the open savannahs. Nilgai and wild boar Sus scrofa formed smaller groups while barking deer Muntiacus muntjak and hog deer Axis porcinus were primarily solitary. Chital exhibited a peak in rutting activity during the late hot-dry season and a subsequent birth peak in February. Nilgai exhibited a different pattern, breeding in January and calving during the monsoon, when optimum foraging conditions prevailed.

Environmental Effects of Increased Coal Utilization: Ecological Effects of Gaseous Emissions from Coal Combustion

This report is limited to an evaluation of the ecological and environmental effects of gaseous emissions and aerosols of various types which result from coal combustion. It deals with NOx, SOx, fine particulate, photochemical oxidant and acid precipitation as these pollutants affect natural and managed resources and ecosystems. Also, synergistic effects involving two or more pollutants are evaluated as well as ecosystem level effects of gaseous pollutants. There is a brief summary of the effects on materials and atmospheric visibility of increased coal combustion. The economic implications of ecological effects are identified to the extent they can be determined within acceptable limits. Aquatic and terrestrial effects are distinguished where the pollutants in question are clearly problems in both media. At present, acid precipitation is most abundant in the north central and northeastern states. Total SOx and NOx emissions are projected to remain high in these regions while increasing relatively more in the western than in the eastern regions of the country. A variety of ecological processes are affected and altered by air pollution. Such processes include community succession and retrogression, nutrient biogeochemical cycling, photosynthetic activity, primary and secondary productivity, species diversity and community stability. Estimates of the non health-related cost of air pollutants range from several hundred million dollars to $1.7 billion dollars per year. In general, these estimates include only those relatively easily measured considerations such as the known losses to cultivate crops from acute air pollution episodes or the cost of frequent repainting required as a result of air pollution. No substantial nationwide estimates of losses to forest productivity, natural ecosystem productivity which is tapped by domestic grazing animals and wildlife, and other significant dollar losses are available.

Environmental effects of increased coal utilization: ecological effects of gaseous emissions from coal combustion.

This report is limited to an evaluation of the ecological and environmental effects of gaseous emissions and aerosols of various types which result from coal combustion. It deals with NOx, SOx, fine particulate, photochemical oxidant and acid precipitation as these pollutants affect natural and managed resources and ecosystems. Also, synergistic effects involving two or more pollutants are evaluated as well as ecosystem level effects of gaseous pollutants. There is a brief summary of the effects on materials and atmospheric visibility of increased coal combustion. The economic implications of ecological effects are identified to the extent they can be determined within acceptable limits. Aquatic and terrestrial effects are distinguished where the pollutants in question are clearly problems in both media. At present, acid precipitation is most abundant in the north central and northeastern states. Total SOx and NOx emissions are projected to remain high in these regions while increasing relatively more in the western than in the eastern regions of the country. A variety of ecological processes are affected and altered by air pollution. Such processes include community succession and retrogression, nutrient biogeochemical cycling, photosynthetic activity, primary and secondary productivity, species diversity and community stability. Estimates of the non health-related cost of air pollutants range from several hundred million dollars to $1.7 billion dollars per year. In general, these estimates include only those relatively easily measured considerations such as the known losses to cultivate crops from acute air pollution episodes or the cost of frequent repainting required as a result of air pollution. No substantial nationwide estimates of losses to forest productivity, natural ecosystem productivity which is tapped by domestic grazing animals and wildlife, and other significant dollar losses are available.

Water-Plant and Soil Consumption by Guereza Monkeys (Colobus guereza): A Relationship with Minerals and Toxins in the Diet?

Black-and-white colobus monkeys, Colobus guereza, were frequently observed coming to the ground in a swamp and eating water plants at a site in western Uganda. Normally, guereza intergroup relationships were antagonistic, but many groups shared the swamp pools. Analysis of water-plant samples indicated high levels of sodium, iron, manganese, and zinc compared with other items of the guereza's leaf-dominated diet. There was also evidence of clay consumption by guerezas at a stream bank in the same area. Analysis of the clay showed it to contain considerably more magnesium, iron, and copper than neighboring soils. A comparison of estimated mineral intakes and requirements suggests that the dry-land diet of the guereza population may be deficient in sodium, and perhaps barely sufficient in copper, manganese, and zinc. Water-plant consumption may remedy mineral deficiencies, but clay may be consumed for other reasons: to adsorb plant toxins or to adjust the pH of the forestomach. AN HERBIVOROUS DIET can be deficient in essential minerals. Underwood (1971) lists many instances of deficiency disease in domestic grazing animals caused by low mineral levels in pasture. Wild mammalian herbivores (including ungulates, elephants, and primates) are often observed to, ingest soil, and reports of this behavior frequently propose or imply that its function is the acquisition of minerals. In several cases the sodium content of the soil is suggested to have particular significance (Stockstad et al. 1953; Schaller 1963; Dalke et al. 1965; Weir 1969, 1973; Weeks and Kirkpatrick 1976). Although sodium is one of the major constituents of animal bodies (Pike and Brown 1975), the aboveground parts of land plants rarely contain much of this element (Sutcliffe 1962). Soil consumption is not the only way in which herbivores may remedy mineral deficiencies. Botkin et al. (1973) suggest that water-plant consumption by moose on Isle Royale, Lake Superior, makes up for sodium deficiency in the animals' dry-land diet. The diet of colobine monkeys is composed largely or wholly of plant material, including considerable quantities of tree leaves and leaf buds (Yoshiba 1967, Ripley 1970, Hladik and Hladik 1972, Horwich 1972, Clutton-Brock 1975, Struhsaker and Oates 1975), and there are numerous reports of soil ingestion by colobines (McCann 1934, Pitman 1954, Rahm and Christiaensen 1960, Gee 1961, Poirier 1970, Ripley 1970, Clutton-Brock 1972, Hladik and Hladik 1972). Most of these reports have not been accompanied by any detailed analysis of the soil consumed, or by a discussion of the behavior's significance. Hladik and Gueguen (1974) have, however, analyzed termite-nest clay consumed by Presbytis species in Sri Lanka (and by chimpanzees in Gabon). After comparisons with some plant materials eaten by the animals, Hladik and Gueguen conclude that the clays may have been ingested for the tactile sensation they produce in the mouth or because of a physico-chemical action they perform in the gut, rather than for their mineral content. During field studies at a site in western Uganda, I observed black-and-white colobus monkeys, or guerezas (Colobus guereza Riippell), behaving unusually on the ground. The animals frequently ate plants growing in pools of water, and there was evidence that they consumed clay from small caves. To investigate whether by these means the monkeys might be obtaining minerals deficient in their diet, analyses were performed on samples of the water plants and clay and, for comparison, on samples of dry-land items of diet and soil collected away from the caves. This paper presents details of this gLereza behavior and the results of the plant and soil analyses. The guereza's likely mineral requirements are reviewed, and the extent to which these would be met by the normal diet is assessed. In this light, the water-plant and clay ingestion is discussed.

Population Decline of an Insular Population of Armenian Wild Sheep in Iran

From 1970 to 1973, an insular population of Armenian wild sheep (Ovis orientalis gmelinii) in an area of 3145 hectares declined from an estimated 3500 to 1000. The dry spring and summer of 1971, the severe winter of 1971-72, and the poor range conditions engendered by heavy overstocking were the major factors contributing to the 1971-72 die-off. During that die-off less than 1 percent of the lamb crop survived. Net productivity during 1971, 1972, and 1973 was 14 percent, less than 1 percent, and 15 percent respectively. Under present poor range conditions, the recommended population level is 500 animals. J. WILDL. MANAGE. 41(4):720-725 Kabudan Island, situated in northwestern Iran (Fig. 1), is inhabitated by a population of Armenian wild sheep which were introduced in unknown numbers from the mainland in the nineteenth century (Nasonov 1923). When the island was declared a wildlife refuge in 1967, all domestic sheep and goat grazing was prohibited. Except for 2 game wardens who patrol the area, there are no permanent human inhabitants on the island. To establish natural predation, an adult male and female leopard (Panthera pardus) trapped in northeastern Iran were introduced on the island in 1969. Limited hunting of wild sheep was allowed on the island until 1973. The population dynamics of the wild sheep population were documented between May 1971 and May 1975. We thank the Iran Department of the Environment field personnel for their assistance and in particular the Director, H. E. Eskandar Firouz, for his support of these studies.