Grazing in remnant woodland vegetation: changes in species composition and life form groups

Abstract. Grazing by domestic livestock in native woodlands can have major effects on ecosystem functioning by the removal of plant species that form important functional groups. This paper documents the changes in floristics in a large group of remnants of native woodland left after agricultural clearing in southwestern Australia. Species richness and diversity were significantly reduced in remnants and the proportion of exotic species increased. Detrended Correspondence Analysis (DCA) was used to identify floristic and environmental patterns among plots and identified two distinct groups based on grazing intensity. This indicated that the significance of the relationship between grazing effects and DCA floristic axes was greater than edaphic characteristics that normally influence floristic patterns. Floristic characteristics of sites that were influencing the position of plots on the ordination diagram included proportion of exotic species and proportion of native perennial shrubs and herbs. Numbers of species of native shrubs and perennial herbs were significantly reduced in grazed plots and numbers of exotic annual grasses and herbs were significantly higher. Other life form groups such as native perennial grasses and geophytes were not significantly affected by grazing. Reproductive strategies of perennial species showed a significant decrease in numbers of resprouters and a significant increase in numbers of facultative seeder/sprouters. Exclosure plots showed increases in number and cover of perennial shrubs and herbs after three years whereas number and cover of exotic species did not change. Time series DCA showed that the floristic composition of exclosure plots in grazed sites became closer to that of the ungrazed sites.     

What does it take to do successful adaptive management? A case study highlighting Coastal Grassy Woodland restoration at Yanakie Isthmus

The case study of the Yanakie Isthmus Coastal Grassy Woodland Restoration Program, Victoria, Australia, illustrates the steps necessary to deliver a complex, long‐term adaptive management project involving a range of stakeholders at a landscape scale. Perspectives of the land manager, scientist and volunteer help to convey successes and lessons learned.     

Quantitative investigations on nematode-trapping hyphomycetes from woodland soils

Abstract From three different woodland types in Berlin (West) (poor sandy pine forest, mesotrophic beech forest and a sporadically inundated river bank), nematode-destroying hyphomycetes were isolated using the sprinkled plates method. 16.4% of the plates yielded isolates, one predacious fungus per 8 g of fresh soil. The fungi obtained belonged to ten species out of four different genera. The highest number of isolates was obtained from the beech forest, while the lowland forest yielded the highest number of species but the lowest amount of isolates. The differences between the various soil types are discussed. The results indicated that attempt to quantify the nematode-destroying hyphomycetes may be successful.     

Holocene vegetation and land-use history in the environs of Lake Kahala, northern Estonia

Pollen profiles, based cores taken in Lake Kahala and from the adjoining mire, were used to establish general vegetation history and to reconstruct the extent and types of land-use over most of the Holocene. Modern pollen deposition was studied using moss polsters and the results were used in the interpretation of the fossil pollen data in terms of former land-use practices. The modern-day samples are from settlements, hay meadow and pasture, and overgrown pasture. Indications of human activity can be traced back to the Stone Age. At ca. 6400 cal. B.C., the first indications of possible woodland utilisation by humans are recorded. This may have involved grazing within the forests. From 4200 cal. B.C. onwards, animal husbandry with changing intensity was practised. Arable farming, involving cereals, was introduced to the area at ca. 1800 cal. B.C., but it was only at ca. 500 cal. B.C. that it assumed an important role in the farming economy.Secale cereale (rye) was introduced during the Roman Iron Age, intensive rye cultivation started at the end of the Iron Age, at ca. cal. A.D. 800. Ever increasing farming pressures triggered the formation of openalvars. Open landscape similar to that of today has persisted, with minor forest regeneration phases, since at least 500 cal. B.C.     

Change in the vegetation mosaic of central Arizona USA between 1940 and 1989

The landscape of central Arizona U.S.A. is characterized by a patchy distribution of three major vegetation types: chaparral, woodland and grassland. Disturbance is common in the landscape, primarily livestock grazing, fire and conversion (i.e., removal of woody plants to increase forage for livestock). The purposes of this research were to determine changes in the landscape mosaic of central Arizona between 1940 and 1989 and to predict future changes. Using aerial photographs from 1940, 1968 and 1989 and digital overlays followed by transition matrix analysis, we found that chaparral and its adjacent grassland had changed less than woodland and its grassland. However, both had nearly equal projected stabilization times. Moreover, disturbance increased time for stabilization and some results were scale-dependent.     

Treponematosis: a possible case from the late prehistoric of North Carolina

The skeleton of an adult female exhibiting evidence of treponemal infection was recently recovered from the Hardin site in the piedmont region of North Carolina. Archaeological indicators suggest a late prehistoric affiliation. The skeleton is affected by a diffuse process resulting in surface changes, both destructive and appositional, node formation and shaft expansion, medullary encroachment and filling, cortical thickening, and fracture. There is both cranial and postcranial involvement. While treponemal infection is indicated, the atypical nature of the total pattern raises the possibility of multiple pathological processes operating simultaneously. The significance of this case is threefold. It provides information on the ability of prehistoric peoples to cope with disease. It reminds the paleopathologist of the dangers inherent in attempts at singular and specific diagnoses. It sheds new light on the epidemiology of the treponemal diseases.     

Development of selective tolerance to the serotonin behavioral syndrome and suppression of locomotor activity after repeated administration of either 5-MeODMT or mCPP

Repeated administration to rats of the 5-HT -selective agonist 5-methoxy-N, N-dimethyltryptamine (5-MeODMT)^1A produced tolerance to the ability of a test dose of 5-MeODMT to produce the serotonin behavioral syndrome, but not to the ability of a test dose of the 5-HT_1B -selective agonist m-chlorophenylpiperazine (mCPP) to decrease locomotor activity. Conversely, repeated administration of mCPP produced tolerance to the ability of a test dose of mCPP to decrease locomotor activity, but not to the ability of a test dose of 5-MeODMT to elicit the serotonin behavioral syndrome. The lack of cross-tolerance between these two selective agonists is consistent with the idea that the serotonin behavioral syndrome and suppression of locomotor activity are mediated by different subtypes of the 5-HT₁ receptor.     

Vegetation and soils of seminatural deciduous woods in northeast Ireland

Seminatural deciduous woods associated mainly with basaltic escarpments were surveyed in northeast Ireland to investigate the relationships between soil physical and chemical characteristics and community composition. Gradients of floristic composition in the sample stands pointed to soil acidity, soil mineral nutrient status and the degree of soil waterlogging as principal factors influencing the ground flora.The physico-chemical characteristics of the woodland soils showed distinctive differences which were correlated with community composition, confirming the considerable effect of the soil environment. Soil texture was shown to be a key factor influencing the ground flora, mainly through its influence on soil water status and acidity.Better drained soils subject to minimal disturbance by people or physiographic processes, were found to have the highest content of water soluble nitrogen, available phosphorus and exchangeable potassium. An interaction between soils, site geomorphology and land use suggested that the value of the woods as controls against which the effects of agricultural land use on soils can be monitored, is limited.Nomenclature follows Webb (1977) for vascular plants and Watson (1968) for bryophytes.A grant from the British Ecological Society helped to finance part of the field work for this project. Gary McClure carried out soil physico-chemical analysis.     

Discriminant analysis some east Tennessee forest herb niches

Niche differences in four species of Galium were quantified by using discriminant function analysis (DFA) of site characteristics including biotic variables. Data were analyzed separately for a mesic hardwood site and cedar barrens. Significant differences in niche centroids were also determined for 17 co-occurring herbs in the mesic hardwood site using similar variables. Variables used in the analysis included site characteristics such as aspect and percent slope, biotic variables such as total woody basal area and litter composition, and soil characteristics (for the seventeen species) including pH and texture. Biotic variables were included as indicators of environmental variables and possible allelopathic influence.In the Galium data, variables highly correlated with discriminant axes included canopy density, litter type, and overstory type. In the co-occurring species data, litter composition, slope position, soil pH and texture, and steepness of slope were most correlated with discriminant axes. Discriminant axes derived from the Galium cedar barren data set proved a poor predictor of species occurrence in the mesic hardwood site.The utility of DFA in plant niche analysis is discussed.Nomenclature follows: Fernald, M. L., 1950. Gray's manual of botany. American Book Co., Atlanta, Georgia, USA.Research sponsored by the Office of Health and Environmental Research, U.S. Department of Energy, under contract W-7405-eng-26 with Union Carbide Corporation. Publication No. 2031, Environmental Sciences Division, ORNL. We would like to thank Lynn Tharp for assistance with computer problems, and Drs. Mac Post and Bob O'Neill for many useful comments. We are grateful to Tom Kitchings for providing overstory data.