Sarangzai, Atta Mohammad (2000) POPULATION STRUCTURE AND NATURAL REGENERATION POTENTIAL OF JUNIPERUS EXCELSA (M.BIEB) IN NORTHERN BALOCHISTAN PAKISTAN. PhD thesis, University of Balochistan, Quetta.
A quantitative study was conducted in 66 mono-specific stands of juniper (juniperus excelsa, M. Bieb) forests in four adjacent districts of northern Balochistan. Only 33 species were found along with juniper among which the frequency of sharubs were accounted (28%) followed by herbs (non grasses) (57%) while grasses contributed only (15%) the density of juniper trees (>6cm dbh) ranged from 88-376 stem/ha with a mean of 214 individuals/ha. The average basal area was 33.77 m2ha-1 Higher densities were recorded for relatively undisturbed stands and on the north facing slopes. Juniper density and basal area was significantly correlated (r=0.73, P<0.001). Diameter distributions within the stands were mostly skewed and uni-model with gaps appearing in the large size classes. Adequate recruitment of Juniper seedlings were observed. Seedling and sapling (<6 cm dbh) desities in 66 stands were average 104+24 ha Highest average seedlings density (ha-1) and basal area (cm2ha-1) recorded from north east facing sloping. Seedling density and its basal area (82%) was higher, the percentage of filled seeds was 13-31%. The over-mature trees and the trees growing on dry sites, produced low quality seeds while medium-size trees from Sasnamana were better seed bearers. The possibility of mast years in juniper also exists and the variation in seed size and seed size class frequency could be due to adaptive polymorphism The intensity of infection of juniper dwarf mistletoe was high in Chasnak valley than Sasnamana valley. This is reflected in percent of infection and area DMR (Dwarf Mistletoe Rating) for the two valley are infected with a mean rate of DMR=0.90. The differences in infection may be related in forest conditions and topographic factors between the two valleys. Higher elevations range 2800-3000 meters and south-western aspects appeared to favour the highest incidence of infection and there is high potential from tree to tree spread in both of the two valleys. The soils of the study areas were coarse textured (sandy-loam and loamy sand) basic in reaction and free from salinity- Organic matter contents were deficit, with low amount of dissolved salts. Soil also indicated was observed between tree density basal area, seedling density and soil characteristics. Results of present studies indicate that juniper forests are rapidly degrading due to human disturbances.
|Item Type:||Thesis (PhD)|
|Uncontrolled Keywords:||juniperus excelsa (m.bieb), northern balochistan, juniper, sasnamana, chasnak, ziarat|
|Subjects:||Biological & Medical Sciences (c) > Biological Sciences(c1) > Paleo-botany(c1.9)|
|Deposited By:||Mr. Muhammad Asif|
|Deposited On:||23 Nov 2006|
|Last Modified:||04 Oct 2007 21:03|
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