首页|Distributional patterns of herb growth forms along elevation and grazing pressure gradient.
Distributional patterns of herb growth forms along elevation and grazing pressure gradient.
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NSTL
Distribution of herb growth forms in the understorey of some village resource forests in Central Himalaya (Uttar Pradesh, India) was studied along elevation and grazing pressure gradient. Vegetation of the area is generally associated with forest pattern varying from tropical sal (Shorea robusta) to subtropical Chir pine (Pinus roxburghii) and Chir pine mixed broadleaved forests. Six representative village forests were selected which may be broadly grouped into three categories on the basis of elevation: (i) low elevation zone - Dogra (800 m) and Dolmar (900 m); (ii) mid-elevation zone - Bhaluti (1280 m) and Jeolikote (1300 m); and (iii) high elevation zone - Gethia (1580 m) and Nainagaon (1610 m). The sites were further divided into three subsites on the basis of increasing level of grazing pressure as: least, moderately and severely disturbed site. Herb growth forms were characterized as: erect forms, umbrella-like, basal leaf form, sprawling mats and graminoids. Erect and umbrella-like forms registered an increase in their share in the herb growth form spectrum with increase in elevation while basal leaf forms and sprawling mats exhibit better representation at low elevation. Grazing affects the distribution pattern of herb growth form by inhibiting regeneration through restricting seed setting, overexploitation and modifying processes relating to competition. Grazing most adversely affects erect forms but promotes herb growth form diversity. Umbrella-like forms, basal leaf forms and sprawling mats prefer disturbed sites. Generally, better growth form diversity occurred at low elevation and grazed sites. Irrespective of the altitude and biotic pressure, erect forms dominate the herb growth form spectrum followed by the graminoids.
NSTL
