Smith, Philip Edward (1978) The functional response of plants to trampling pressure. Doctoral thesis, Keele University.

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he responses of Calluna vulgaris, Phleum bertolonii and Plantago lanceolata to trampling pressure, applied at controlled intensities and frequencies, were investigated.
Substantial water stresses develop within shoots of C, vulgaris following damage. The magnitude of such stresses is related to the plant's ability to avoid desiccation and the consequences of such stresses on plant survival are related to its capacity to tolerate desiccation. Both physiological parameters are influenced by plant microclimate, which also has repercussions on the rapidity with which water stresses develop following trampling and the degree of desiccation injury suffered by the plant. Net primary productivity is also reduced by trampling pressures, both through direct mechanical effects and the effects of water stress on plant assimilation and metabolic activity. The susceptibility of the plant to water stress is variable, being related to environmental factors and the stage of development of the plant. Consequently, tolerance by C. vulgaris to trampling may be regarded as variable. The responses of P. bertolonii and P, lanceolata to simulated pressures have been considered in terms of the plant's capacity to recover following damage. Trampling induced soil compaction may have a detrimental effect on the ability of the plant to grow. Simulated trampling results in damage and defoliation of the shoot. Evidence indicates that following damage, an elevation in growth rate may occur which may be related to an increased photosynthetic capacity. These effects have been discussed in relation to hypothetical consequences of reduced competition for root produced metabolites and the role of assimilates in aiding recovery. It is postulated that increased durability of the plant to trampling pressure is dependent upon increased growth rates.
Since both tolerance and recovery following trampling are variable and dependent upon plant function, it is suggested that the 'carrying capacity' of vegetation is variable and related to the physiological activity of individuals composing the community.

Item Type: Thesis (Doctoral)
Subjects: Q Science > QH Natural history > QH301 Biology
Divisions: Faculty of Natural Sciences > School of Life Sciences
Depositing User: Lisa Bailey
Date Deposited: 24 Sep 2019 14:21
Last Modified: 24 Sep 2019 14:21

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