Grazing and fire in two subalpine peatlands

2007 ◽  
Vol 55 (1) ◽  
pp. 42 ◽  
Author(s):  
Keith L. McDougall
Keyword(s):  
Exotic Species ◽  
Native Species ◽  
Floristic Composition ◽  
High Plains ◽  
Composition And Structure ◽  
North Eastern ◽  
Salix Cinerea ◽  
Burnt Areas

The floristic composition and structure of peatland vegetation in adjoining subalpine catchments of the Bogong High Plains (north-eastern Victoria) were monitored between 1979 and 2006. Grazing by cattle had been excluded from one catchment since 1946, when it was fenced. Peatland vegetation in both catchments was partially burnt in a wildfire in 2003. Between 1979 and 1999, in the ungrazed peatland, the cover of Sphagnum cristatum Hampe and Baeckea gunniana Schauer increased and the cover of pools decreased, whereas in the grazed peatland the cover of B. gunniana and Epacris paludosa R.Br. decreased and the cover of Empodisma minus (Hook.f.) L.A.S.Johnson & D.F.Cutler increased. The cover of all recorded species decreased following a fire in 2003. Between 2004 and 2006, a significant increase in cover was detected in two of eight species measured in burnt areas. In burnt areas, the number of native species per quadrat increased in the grazed peatland and the numbers of exotic species per quadrat increased in both peatlands over that period. By 2006, the peatlands had largely recovered floristically from the 2003 fires but it is likely to be decades before the cover of S. cristatum and Richea continentis B.L.Burtt. reaches pre-fire levels. Control of several exotic species that established after the fire (especially Salix cinerea L. and Juncus spp.) may be required.

scholarly journals Contemporary Ornamental Gardens: Trans-Nationalisation, Landscaping and Biodiversity. An Exploratory Study in Medellín, Colombia

2015 ◽  
Vol 68 (1) ◽  
pp. 7557-7568
Author(s):  
Luis Anibal Vélez Restrepo ◽  
Mauricio Herrera Villa
Keyword(s):  
Exotic Species ◽  
Native Species ◽  
Urban Landscape ◽  
Floristic Composition ◽  
Private Companies ◽  
Public Gardens ◽  
Urban Gardening ◽  
Vegetation Landscape ◽  
As Species ◽  
Environmental Public Policy

The incorporation of ornamental vegetal species into public green areas is an important feature within the renewal and spreading processes in the urban landscape. In developing countries such as Colombia, there is a lack of studies aimed at analyzing the set of species used in the urban gardening, where do these species come from and their potential environmental impacts. The non-arboreal ornamental vegetation found in public gardens such as: medians, front gardens, parks, public institutions and private companies in the Southeastern area in Medellín was analyzed. Through statistical sampling it was possible to identify the floristic composition and the vegetation landscape features. Within 143 analyzed spaces, it was found predominance from non-native species. From 198 species, 158 are exotic species; from these exotic species 68 have been incorporated along the last 10 years. From the total, 93 are mentioned in the literature as species with a potential risk: invasive, urticant or toxic. The results allowed questioning the landscape activity compared to the plant material used. These results show the weakness or inefficiency of the environmental public policy about the species entry and propagation criteria and mechanisms control in nurseries. It is evident the need to go further in researches about ecologically functional native and exotic species within the city.

Changes in Floristic Composition of Urban Bushland Invaded by Pittosporum undulatum in Northern Sydney, Australia

1997 ◽  
Vol 45 (1) ◽  
pp. 123 ◽  
Author(s):  
Stefan Rose ◽  
Peter G. Fairweather
Keyword(s):  
Species Richness ◽  
Exotic Species ◽  
Native Species ◽  
Floristic Composition ◽  
Individual Species ◽  
Community Pattern ◽  
Edaphic Conditions ◽  
Management Effort ◽  
Relative Cover ◽  
Native Species Richness

Differences in species composition of urban bushland sites that had been subjected to increasing degradation and progressive invasion of Pittosporum undulatum Vent. were assessed using nonparametric multivariate and other statistical techniques. Increasing suburb age was found to significantly affect community pattern as a whole, specifically through increased proportions of exotic species, decreased native species richness and sustained shifts in the relative importance of individual species. Older suburbs were typified by species that were mesic, fire-sensitive, shade-tolerant and adapted to relatively moist, nutrient-rich edaphic conditions. These species included P. undulatum and many invasive exotics. Many native species decreased substantially in rank importance with increasing suburb age, to the point of elimination in older suburbs. These included one vulnerable taxon (Tetratheca glandulosa Sm.). Overall community pattern was correlated with abundance of P. undulatum, fire and human disturbance. Relative cover of P. undulatum was found to be significantly correlated with increased proportions of exotic species and reduced native species richness and diversity. While most exotic species were concentrated within 30 m of the suburban edge, it is suggested that most management effort should be directed at those exotic species that commonly establish throughout bushland remnants. The study also provided an opportunity to test the application of the multivariate software package PRIMER in assessing environmental impact on vegetation communities.

Alpine and Subalpine Wetland Vegetation on the Bogong High Plains, South-eastern Australia

1999 ◽  
Vol 47 (2) ◽  
pp. 165 ◽  
Author(s):  
C.-H. Wahren ◽  
R. J. Williams ◽  
W. A. Papst
Keyword(s):  
Soil Depth ◽  
Vegetation Type ◽  
Soil Surface ◽  
Wetland Vegetation ◽  
High Plains ◽  
Composition And Structure ◽  
Eastern Australia ◽  
Drainage Channels ◽  
Floristic Variation ◽  
Steep Slopes

The botanical composition and structure of wetland vegetation from seven sites in the alpine and subalpine tracts of the Bogong High Plains was sampled in 1995 and 1996. Sites were in the vicinity of Mts Nelse, Cope and Fainter. Sampling was based on contiguous 1-m2 quadrats along transects 20−70 m long across each wetland. Samples were ordinated using non-metric multidimensional scaling (NMDS). Floristic variation was assessed both within selected individual wetlands, and between wetlands from different regions. The relationship between the ordinations and environmental variables such as soil surface texture, soil depth and the amount of bare ground was tested by fitting vectors. Three dominant vegetation assemblages were identified. Closed heath, of hygrophyllous, scleromorphic shrubs such as Richea continentis and Baeckea gunniana, the rush Empodisma minus and the moss Sphagnum cristatum occurred on the deeper peats. Low open heath of Epacris glacialis and Danthonia nivicola occurred on shallow peats. Herbfields of Caltha introloba and Oreobolus pumilio occurred on stony pavements in two different physiographic situations&horbar;on relatively steep slopes (10−20°) at the head of wetlands, and on flat ground (slope < 2°), below the head of wetlands. The pavements on the steeper sites appeared to be associated with periglacial features such as solifluction lobes and terraces. Those on the flatter ground appeared to have been derived more recently. Wetlands in the Mt Cope region consisted of closed heath, low open heath and pavement herbfield in various proportions. Wetlands on Mt Fainter, which are subject to heavy trampling by cattle, were in a degraded condition, with a low cover of major hygrophyllous mosses and shrubs, and a high cover of introduced species. Long-ungrazed wetlands in a 50-year exclosure at Rocky Valley had high cover of closed heath, no pavements, numerous ponds and virtually no entrenched drainage channels or exposed peat. The Caltha herbfields are significant features nationally, both floristically and geomorphologically. Alpine and subalpine wetlands have been listed under the Victorian Flora and Fauna Guarantee Act 1988, and continued grazing by cattle is not compatible with the conservation objectives for this alpine vegetation type.

scholarly journals Urbanization effects on the composition and structure of macrophytes communities in a lotic ecosystem of Pernambuco State, Brazil

2016 ◽  
Vol 76 (4) ◽  
pp. 888-897 ◽  
Author(s):  
L. R. C. C. Xavier ◽  
F. Scherner ◽  
D. C. Burgos ◽  
R. C. Barreto ◽  
S. M. B. Pereira
Keyword(s):  
Urban Areas ◽  
Floristic Composition ◽  
Freshwater Ecosystems ◽  
Metropolitan Region ◽  
Macrophyte Communities ◽  
Composition And Structure ◽  
Lotic Ecosystem ◽  
Dry Seasons ◽  
Urbanized Areas ◽  
Wet And Dry Seasons

Abstract Population growth in urban areas changes freshwater ecosystems, and this can have consequences for macrophyte communities as can be seen in the municipalities that border the Capibaribe River, Pernambuco, Brazil. This study reports the effects of urbanization on the composition and structure of macrophyte communities in areas along that river. The following urbanized and non-urbanized sampling sites were chosen: Sites 1 and 2 (municipality of Santa Cruz do Capibaribe), Sites 3 and 4 (municipality of Toritama), and Sites 5 and 6 (metropolitan region of Recife). These sites were visited every two months from January to July 2013 to observe seasonal variation (wet and dry seasons). Thirty-one species were identified. Generally, the non-urbanized sites had a higher number of species. Multivariate analyses indicated significant overall differences between urbanized and non-urbanized areas (R = 0.044; p < 0.001) and between seasons (R = 0.018; p < 0.019). Owing to the large variation in physical, chemical, and biological characteristics between urbanized and non-urbanized areas, we found that urbanization significantly influenced the floristic composition and structure of macrophyte communities.

scholarly journals Anuran larvae diet from agroecosystem’s ponds: environmental quality and implications for their populations

2016 ◽  
Author(s):  
Selene Babini ◽  
Luciana Cibils Martina ◽  
Elisa Luque ◽  
Noemi Gari ◽  
Nancy Salas ◽  
...  
Keyword(s):  
Environmental Quality ◽  
Native Species ◽  
Morphometric Parameters ◽  
Diet Analysis ◽  
Temporary Ponds ◽  
Nitzschia Palea ◽  
Composition And Structure ◽  
Structural Variables ◽  
Algal Abundance

<p>Agriculture is considered an important factor for the decline of amphibians recorded in the last decades. Intensive agriculture requires the application of great amounts of pesticides and fertilizers, consequently many aquatic habitats have been altered. The over-enrichment of waters with nutrients from agriculture causes growth of algae and cyanobacteria and the shift of the community composition toward the dominance of tolerant taxa. The aim of this study was to analyze the diet of tadpoles and the size of larvae and metamorphs of the native species <em>Rhinella arenarum </em>in agroecosystems of central Argentina. Four sampling sites with different degree of human disturbance were selected, three temporary ponds from agroecosystems (A1, A2, A3), and a pond in a semi-modified landscape, not affected by agriculture or cattle. The sites were visited once a week from October 2013 to January 2014. Tadpoles and metamorphs were captured, anesthetize and preserved. Morphometric parameters were measured on tadpoles and metamorphs and for 20 tadpoles the complete intestine was removed and their contents analyzed. Phosphate values were higher in agroecosystem ponds. Body size and mass of tadpoles and metamorphs were different between sites, being smaller in agricultural ponds. Diet analysis revealed that all larvae mainly consumed microalgae. Larval diets allowed differentiating the sites, larvae from A1 and A3 sites showed a diet with a similar composition and structure (with a predominance of <em>Nitzschia palea</em>), meanwhile larvae from A2 and SM showed different diets. In SM, the larvae mainly consumed <em>Trachelomonas </em>sp. Analysis of structural variables revealed a higher algal abundance in the diet of larvae from A3, a lower richness in SM and that there were no differences between sites in diversity and evenness of diets. Our hypothesis was support in part, given that resistant algae taxa were found in agroecosystem ponds and tadpoles and metamorphs were smaller, but larval diets showed higher abundance and richness. The analysis of the diet of aquatic stages of <em>R. arenarum</em> allowed us to know the trophic availability and environmental quality of temporary ponds from agroecosystems. </p>

scholarly journals Community Arctio-Artemisetum vulgaris (Tx. 1942) Oberd. et al. 1967.: The most widespread ruderal community at Pancevacki rit

2009 ◽  
Vol 24 (2) ◽  
pp. 113-121
Author(s):  
Radmila Stankovic-Kalezic ◽  
Slobodan Jovanovic ◽  
Vaskrsija Janjic ◽  
Ljiljana Radivojevic
Keyword(s):  
Floristic Composition ◽  
Anthropogenic Influences ◽  
Composition And Structure

A several-year investigation of distribution, phytocoenological differentiation, floristic composition and structure of the ruderal flora and vegetation, and relative anthropogenic influences was conducted in the area of Pancevacki rit. The study focused on the ruderal community Arctio-Artemisetum vulgaris, the most widespread of 10 ruderal communities identified in a detailed phytocoenological analysis of the location of Pancevacki rit.

scholarly journals Alien Species vs. Native Species: From Community Ecology to Eco-Evolutionary Dynamics

2019 ◽  
Author(s):  
Andersonn Silveira Prestes
Keyword(s):  
Alien Species ◽  
Exotic Species ◽  
Native Species ◽  
Evolutionary Dynamics ◽  
Evolutionary Processes ◽  
Native Communities ◽  
Individualized Approach ◽  
History Of ◽  
Relationship Of ◽  
The Relationship

The establishment and spread of exotic species is a contemporary major concern. Alien species may become invasive in their new habitat, leading to both/either environmental and/or economic impacts. I briefly reviewed the literature in the last decade about the relationship of exotic species and native communities. I identified that professionals usually approach the subject in two main points of view: (1) researchers tend to point out the impacts of alien species on entire communities, evaluating if the relationship is positive, negative or neutral; (2) they focus on the eco-evolutionary processes involved in the introductions, the dynamics of invasion, and individual study cases. When evaluating the response of introductions to entire communities, evidence seems to be ambiguous and may support positive, negative or neutral relationship, especially depending on the scale approached. The unique eco-evolutionary pathways of each introduction may be a great shortcoming in the searching for generalities. On the other hand, advances have been made in understanding the dynamics of invasion on different lineages through a more selective/individualized approach. I suggest that the dynamics of invasion might be studied through a perspective in which different eco-evolutionary processes, levels of organization (from gene to entire communities), the history of the organism(s) and time are taken into account. Individual cases might be compared in attempt to understand how the relationship exotic and native works and in the search for generalities.

scholarly journals Intrinsic Prey Preference and Selection of the Giant Gartersnake: A Threatened Predator in a Nonnative Prey-Dominated Community

2020 ◽  
Vol 11 (1) ◽  
pp. 164-173
Author(s):  
Julia S.M. Ersan ◽  
Brian J. Halstead ◽  
Erica L. Wildy ◽  
Michael L. Casazza ◽  
Glenn D. Wylie
Keyword(s):  
Exotic Species ◽  
Native Species ◽  
Prey Selection ◽  
Central Valley ◽  
Prey Preference ◽  
Live Prey ◽  
Species Of Conservation Concern ◽  
Conservation Concern ◽  
Behavioral Trials ◽  
Selection Of

Abstract The introduction of exotic species into an environment can introduce great change in the trophic dynamics of native species. This is of even greater concern if the native species is of conservation concern. The giant gartersnake, Thamnophis gigas, an endemic predator of the Central Valley of California and a species of conservation concern at the state and federal levels, has declined as a result of conversion of its once vast wetland habitat to agriculture. Another anthropogenic factor contributing to this snake's changing ecology is the introduction of nonnative prey into the species' habitats. These introductions have resulted in a prey community that is almost completely composed of exotic species and have potential for considerable effects. In order to assess prey preference and selection we performed three sets of behavioral trials on naïve neonates. We examined 1) neonate prey preference in response to olfactory cues of prepared prey extracts, 2) neonate consumption of different live prey items presented simultaneously; and 3) terrestrial feeding behavior and/or latency to successful attack. Results from the olfactory study suggest that native Sierran treefrogs, Pseudacris sierra, are preferred by neonates. Results from consumption trials suggest that neonates are more likely to select frog species than fish species. This is the first study that we are aware of that examines prey selection of this threatened species and serves to inform its conservation and management.

Superphosphate and stocking rate effects on a native pasture oversown with Stylosanthes humilis in central coastal Queensland. 3. The balance of native species in the pasture

1978 ◽  
Vol 18 (95) ◽  
pp. 808 ◽  
Author(s):  
NH Shaw ◽  
MB Dale
Keyword(s):  
Native Species ◽  
Floristic Composition ◽  
Exchange Capacity ◽  
Response To Treatment ◽  
Data Sets ◽  
Heteropogon Contortus ◽  
Native Pasture ◽  
Total Exchange Capacity ◽  
Highly Correlated ◽  
Stocking Rates

The percentage frequency of all herbaceous species in a native pasture oversown with S. humilis (T.S.) was measured at the beginning and end of an eight-year grazing experiment. Treatments imposed were three levels of molybdenized superphosphate (nil; 125 kg ha-1 annually; 250 kg ha-1 annually plus an extra 250 kg ha-1 initially) in factorial combination with four stocking rates and two sowing methods for T.S. (ground sowing into spaced cultivated strips or aerial sowing). Stocking rates were gradually increased during the experiment and for the last three years overlapping ranges were used for the three fertilizer levels; the overall range was then from 0.55 to 1.65 beast ha-1. Treatments did not induce any major changes in the proportions of native species in the pasture. Heteropogon contortus remained dominant and its frequency increased in all treatments. Of the total of 113 species recorded, only 18 reached 10 per cent frequency in at least one paddock on one occasion. Several of these showed statistically significant changes in response to treatment, but their relative importance was not greatly changed. Examination of the results by principal co-ordinate and canonical analysis, showed that the first vectors of the two data sets were highly correlated, indicating that the major control on floristic composition was not changed by oversowing with T.S. or by the treatments imposed. Treatment effects dominated in the second and third vectors in the final year. The controlling vector was found to be highly correlated with soil calcium, potassium, total exchange capacity and organic carbon, but the basis for the correlations remains undetermined.

Composition and community structure of mangroves distributed on the east coast of Marajó Island, Brazil

2022 ◽  
Author(s):  
Barbara Luzia Santos de Oliveira Faro ◽  
Priscila Sanjuan de Medeiros-Sarmento ◽  
Norma Ely Santos Beltrão ◽  
Paulo Weslem Portal Gomes ◽  
Ana Cláudia Caldeira Tavares-Martins
Keyword(s):  
Floristic Composition ◽  
Distribution Patterns ◽  
Major Influence ◽  
Structural Development ◽  
Black Water ◽  
Composition And Structure ◽  
Marine System ◽  
Marajó Island ◽  
White Water ◽  
Degree Of Similarity

Abstract Mangroves in the Amazon are influenced by several environmental conditions that determine the composition and structural development of the arboreal flora, which results in different distribution patterns. In this study, we sought to answer two questions: (1) what is the composition and structure of the mangroves near the mouth of the Amazon River in Marajó Island? (2) Are the fringe and inland mangroves more similar or dissimilar in terms of floristic composition? For this, we delimited a fringe zone and an inland zone about 1 km apart from each other. In each zone, we distributed five 400-m2 plots. The individuals were grouped into diameter and height classes and structural and phytosociological parameters were calculated. Ten species were recorded in the mangroves, of which seven are typical of white-water (várzea) and black-water (igapó) flooded forest ecosystems. We believed the adjacent ecosystems and the hydrological network are inducing the establishment of such species. The composition and structure of mangroves did not differ statistically between zones, and the degree of similarity may be a result of similar environmental factors in these zones such as low relief and high frequency of macrotides. We conclude that the vegetation of the studied mangroves has a major influence of the fluvial-marine system of the great rivers of the Amazon associated with a diversity of ecosystems that, together, generate greater floristic richness when compared to mangroves in other regions.

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