Large mammalian herbivores not only depend on plant communities for their existence but cause major changes in plant community composition and structure, These changes have direct consequences for ecosystem processes, but recent studies of ungulate-ecosystem relations show widely divergent ungulate effects in different ecosystems. We reviewed studies of ungulate effects on plant community composition to gain insight into potential mechanisms of ungulate-induced changes in both community composition and ecosystem processes. Our analysis of these studies is based on the premise that the effect ungulates exert on plant communities depends on the balance between (1) feeding selectivity of herbivores (i.e., degree to which different plant species or ecotypes experience different levels of tissue loss), and (2) differences among plant species in their ability to recover from tissue loss. A large number of studies clearly show that selective ungulate herbivory leads to the dominance of unpalatable, chemically defended plant species in communities. However, many studies have also demonstrated that intensive long-term herbivory does not lead to the invasion of unpalatable species into the community, and can even increase the dominance of highly palatable species. Our review indicates that high levels of nutrient inputs or recycling and an intermittent temporal pattern of herbivory (often due to migration) are key factors increasing the regrowth capacity of palatable species and hence maintaining their dominance in plant communities supporting abundant herbivores. Key factors limiting ungulate foraging selectivity, again limiting herbivore-induced dominance of slow-growing, unpalatable species, include herding behavior, early growing season and postfire herbivory, asynchronous phenology of palatable versus unpalatable species, and low relative abundance of unpalatable species. Our review indicates differences among ecosystems in the role played by ungulate herbivory result from the relative strength of these factors enhancing plant tolerance to herbivory and limiting foraging selectivity. Anthropogenic changes in these factors (e.g., alteration of migration patterns) therefore have the potential to significantly alter the effects of ungulates on plant communities and ecosystem processes.

/pdf/ungulate-effects-on-the-functional-species-composition-of-1xqen5gp8s.pdf

Ungulate effects on the functional species composition of plant communities: herbivore selectivity and plant tolerance.

Fundamental plant traits such as support, anchorage, and protection against environmental stress depend substantially on biomechanical design. The costs, subsequent trade-offs, and effects on plant performance of mechanical traits are not well understood, but it appears that many of these traits have evolved in response to abiotic and biotic mechanical forces and resource deficits. The relationships between environmental stresses and mechanical traits can be specific and direct, as in responses to strong winds, with structural reinforcement related to plant survival. Some traits such as leaf toughness might provide protection from multiple forms of stress. In both cases, the adaptive value of mechanical traits may vary between habitats, so is best considered in the context of the broader growth environment, not just of the proximate stress. Plants can also show considerable phenotypic plasticity in mechanical traits, allowing adjustment to changing environments across a range of spatial and temporal scales. However, it is not always clear whether a mechanical property is adaptive or a consequence of the physiology associated with stress. Mechanical traits do not only affect plant survival; evidence suggests they have downstream effects on ecosystem organization and functioning (e.g., diversity, trophic relationships, and productivity), but these remain poorly explored.

Plant biomechanics in an ecological context

Comparing hiking, mountain biking and horse riding impacts on vegetation and soils in Australia and the United States of America.

Urban effects, distance, and protected areas in an urbanizing world

Ecotourism effects local cMivironments in many ways. Although some ot the most dramatic envi ronmental changes result from development of the infrastructure to support tourism, more widespread impacts result from the recreational activities that tourists engage in. For ecotourists engaged in adventurous pursuits, hiking and camping are perhaps the most common activ ities that can have profound ecological impacts. This is particularly true in more remote places, protected as parks or wilderness. Of the many environmental effects of hiking and camping, impacts on soil and vege tation have been most thoroughly explored. Consequently, the literature on this subject is voluminous and is a challenge to review thor oughly. The strategy of this chapter is to provide an historical context for the development of this literature, discuss the types of studies that have been employed (cvich with inherent strengths and weaknesses) and briefly assess the geo graphical distribution of research. Emphasis is placed on development of generalities from the

Impacts of hiking and camping on soils and vegetation: a review.

Impacts of recreation, especially of vehicles and walkers, were studied in eight tropical or subtropical public sites in Queensland. In each site, plant species number, vegetation cover, plant height, and species cover and frequency in untrampled, slightly trampled, moderately trampled, and heavily trampled areas were counted or measured. Soil penetration resistance and soil organic matter were also recorded. In two of these eight sites, plant cover, height, leaf length, leaf width, and leaf thickness of each species were measured. Some species of grass such asCynodon dactylon were present in areas subject to all degrees of trampling impact and some tussock species, particularlyEragrostis tenuifolia andSporobolus elongatus, were only present in trampled areas. Woody plants occurred only on untrampled areas. The number of species and all the vegetative measurements mentioned above were reduced as wear increased. Plant height was reduced dramatically by even light trampling. Tall plants appeared to be more sensitive to trampling than short plants. No clear relationship between soil organic matter content and trampling intensity was found.

A survey of trampling effects on vegetation and soil in eight tropical and subtropical sites

The relationship between responses of plants to trampling and their morphological characteristics was studied in a glasshouse experiment. Thirteen species with four different growth forms were used in this experiment. They were five tussock species.Chloris gayana, Eragrostis tenuifolia, Lolium perenne, Panicum maximum, andSporobolus elongatus; three prostate grasses,Axonopus compressus, Cynodon dactylon, andTrifolium repens, two herbaceous species,Daucus glochidiatus andHypochoeris radicata; and three woody species,Acacia macradenia, Acrotriche aggregata, andSida rhombifolia. These species were subjected to three levels of simulated trampling. For each species, measurements were taken of aboveground biomass, root biomass, leaf length, leaf width, leaf thickness, leaf number, broken leaf number and plant height. Overall, these measurements were greatest in the control plants, moderate in the level of light trampling, and the lowest in the level of heavy trampling. Biomass was used as a basis of the assessment of plant resistance to trampling. Three tussock species,Eragrostis tenuifolia, Lolium perenne, andSporobolus elongatus had a high resistance. Woody and erect herbaceous plants were more intolerant to trampling. There appear to be two processes involved in the reduction of the plant parameters: direct physical damage with portions of the plants detached, and physiological changes, which slow down vegetative growth rates. Plant height was found to be the most sensitive indicator of trampling damage.

Plant morphological characteristics and resistance to simulated trampling

Trampling resistance, stem flexibility and leaf strength in nine Australian grasses and herbs

Field occurrence, recovery, and simulated trampling resistance and recovery of two grasses

The morphological responses of some Australian tussock grasses and the importance of tiller number in their resistance to trampling

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Dan Sun

Author Tools

Chat about Author