TITLE

Top-down and bottom-up forces in mammalian herbivore — vegetation systems: an essay review

AUTHOR(S)
Turkington, Roy
PUB. DATE
August 2009
SOURCE
Botany;Aug2009, Vol. 87 Issue 8, p723
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
For almost 50 years ecologists have debated why herbivores generally don’t increase in numbers to such levels as to deplete or devastate vegetation. One hypothesis is that herbivore populations are regulated at low densities by predators, and a second hypotheses is that plants are fundamentally poor food for herbivores. This has lead to two main hypotheses about the role of herbivores in structuring vegetation: the “bottom-up” and “top-down” hypotheses. Here I survey the literature, with a focus on field experiments designed to investigate the soil resource – vegetation – mammalian herbivore system, specifically asking five questions about how each trophic level responds to (i) resource addition, (ii) vegetation removal, (iii) herbivore removal or reduction, (iv) herbivore addition, and (v) the interaction of resource levels and herbivory? I use these to develop 12 testable predictions. I document the major areas of research as they relate to these 12 predictions, and use these to evaluate weaknesses and limitations in field methods. There are surprisingly few terrestrial studies that conduct factorial manipulations of multiple nutrients or herbivores, even though it is clear that these are essential. Specifically, I argue that a manipulative experimental approach is the most valuable way to advance our theory and understanding, and I advocate the continued use of long-term factorial field experiments that simultaneously manipulate soil resources levels and herbivory (preferably at multiple levels), repeated in a range of environments in which individual species or functional groups are monitored.
ACCESSION #
44132351

 

Related Articles

  • Statistical properties of the temperature, relative humidity, and net solar radiation in the Blue Nile-eastern Sudan region. Chong-Yu Xu; Qiang Zhang; El Hag El Tahir, M.; Zengxin Zhang // Theoretical & Applied Climatology;2010, Vol. 101 Issue 3/4, p397 

    This paper presents the results of the first stage of an ongoing project of evaluating the spatial and temporal variability of soil water as fundamental factors for vegetation regeneration in the arid ecosystems in the Blue Nile-eastern Sudan. The specific aim of the present study is to...

  • A Disease-Mediated Trophic Cascade in the Serengeti and its Implications for Ecosystem C. Holdo, Ricardo M.; Sinclair, Anthony R. E.; Dobson, Andrew P.; Metzger, Kristine L.; Bolker, Benjamin M.; Ritchie, Mark E.; Hol, Robert D. // PLoS Biology;Sep2009, Vol. 7 Issue 9, p1 

    Tree cover is a fundamental structural characteristic and driver of ecosystem processes in terrestrial ecosystems, and trees are a major global carbon (C) sink. Fire and herbivores have been hypothesized to play dominant roles in regulating trees in African savannas, but the evidence for this is...

  • Cascading effects from predator removal depend on resource availability in a benthic food web. Sieben, Katrin; Rippen, Anneke D.; Eriksson, Britas Klemens // Marine Biology;Feb2011, Vol. 158 Issue 2, p391 

    We tested joint effects of predator loss and increased resource availability on the grazers' trophic level and the propagation of trophic interactions in a benthic food web by excluding larger predatory fish from cages and manipulating nutrients in the coastal zone of the Baltic Sea. The...

  • An Introduction to the Practice of Ecological Modeling. Jackson, Leland J.; Trebitz, Anett S.; Cottingham, Kathryn L. // BioScience;Aug2000, Vol. 50 Issue 8, p694 

    Discusses the value of modeling as a tool in the study of ecological systems. Advances made in the development of models as a result of computers and graphical software packages; Opinion that the value of modeling lies in its ability to explore ideas not easily pursued through field experience.

  • ROLE OF INDUCED HOST PLANT RESISTANCE IN THE MANAGEMENT OF THRIPS TABACI LINDEMAN (THRIPIDE : THYSANOPTERA) IN ONION. Bandi, Sanjay M.; Sivasubramanian, P. // Agricultural Science Digest;2012, Vol. 32 Issue 3, p219 

    A Field experiment was conducted during September to December 2009 in farmers field at Karapalayam village, Tirupur district, Tamil Nadu with bulb planting of onion to study the effect of induced resistance on the incidence of Thrips tabaci (Thripidae:Thysanoptera) and occurrence of natural...

  • Effects of the herbivorous minnow, southern redbelly dace ( Phoxinus erythrogaster), on stream productivity and ecosystem structure. Bertrand, Katie N.; Gido, Keith B. // Oecologia;Jan2007, Vol. 151 Issue 1, p69 

    We used field and mesocosm experiments to measure effects of southern redbelly dace ( Phoxinus erythrogaster), a grazing minnow, on stream ecosystem structure and function. Ecosystem structure was quantified as algal filament length, algal biomass, size distribution of particulate organic matter...

  • Influence of geogenic factors on microbial communities in metallogenic Australian soils. Reith, Frank; Brugger, Joel; Zammit, Carla M; Gregg, Adrienne L; Goldfarb, Katherine C; Andersen, Gary L; DeSantis, Todd Z; Piceno, Yvette M; Brodie, Eoin L; Lu, Zhenmei; He, Zhili; Zhou, Jizhong; Wakelin, Steven A // ISME Journal: Multidisciplinary Journal of Microbial Ecology;Nov2012, Vol. 6 Issue 11, p2107 

    Links between microbial community assemblages and geogenic factors were assessed in 187 soil samples collected from four metal-rich provinces across Australia. Field-fresh soils and soils incubated with soluble Au(III) complexes were analysed using three-domain multiplex-terminal restriction...

  • Effects of drip irrigation with plastic mulching on the net primary productivity, soil heterotrophic respiration, and net CO2 exchange flux of cotton field ecosystem in Xinjiang, Northwest China. Li Zhi-Guo; Zhang Run-Hua; Lai Dong-Mei; Yan Zheng-Yue; Jiang Li; Tian Chang-yan // Yingyong Shengtai Xuebao;Apr2012, Vol. 23 Issue 4, p1018 

    In April-October, 2009, a field experiment was conducted to study the effects of drip irrigation with plastic mulching (MD) on the net primary productivity (NPP), soil heterotrophic respiration (Rh), and net CO2 exchange flux (NEFCO2 ) of cotton field ecosystem in Xinjiang, taking the...

  • Howling About Trophic Cascades. Kowalewski, David // Australian Journal of Environmental Education;Jul2012, Vol. 28 Issue 1, p17 

    Following evolutionary theory and an agriculture model, ecosystem research has stressed bottom-up dynamics, implying that top wild predators are epiphenomenal effects of more basic causes. As such, they are assumed expendable. A more modern co-evolutionary and wilderness approach —...

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics