PJB-2012-248
THE ECOLOGY AND DYNAMICS OF JUNIPERUS EXCELSA FOREST IN BALOCHISTAN-PAKISTAN
ATTA MOHAMMAD SARANGZAI1*, MOINUDDIN AHMED², ALIA AHMED1, LUBNA TAREEN1 AND SYED UMER JAN3
Abstract
The ecology and dynamics of Ziarat Juniper forests, was analyzed, fifteen stands were sampled during summer 2010. The main results of this research indicate the floristic composition, density ha־¹ and basal area m² ha־¹, physical condition, sex distribution; age and growth rates, and soil analysis. On the basis of mean relative frequency values, herbs were accounted (55.02%), followed by (29.45%) while grasses accounted only (15.52%) across all the stands. Density of juniper trees (>6 cm dbh) ranged from 29 to 268 stems haˉ¹ with a mean 176±77 individuals ha-¹. Highest stand density 268 stem/ha was recorded from Ziarat Prospectus point at elevation 2785 meters from west facing slopes while the lowest stand density 29 stem/ha was from Sasnamana Khawas Neikh on an elevation 2858 meters from north east facing slopes. The over all mean density recorded for juniper trees were 176 ha-¹ with an average basal area 91±41 m²ha-¹.. Juniper density and basal area were not significantly correlated (r= 0.59). Density of seedlings (< 6 m) also varied considerably and ranged from 3676 to 9222 inds/ha with a mean 6450±382 inds/ha. In the present condition Juniperus. excelsa exhibits an adequate recruitment and does not confront any immediate danger, however, if grazing stops in the future. A large number of individuals were recorded alive (62%) as compared with standing dead trees (11%) and recently logged stumps (3%). Trees in the best condition were generally healthy (32%) with living foliage, followed by over mature (14%), while unhealthy juniper (12%) and cut stumps were accounted (12%) respectively. Sex ratio showed predominance of male with a mean value of 100±43 ha-¹ (57%), followed by female 66±29 ha-¹ (38%) while bisexual were very rare (4%) in the population. The combine data show a balanced size class structure. Cross section of ten trees was used to determine age and growth rate. Number of rings in trees with 26 to 69 cm dbh ranged from 113 to 788 years (Mean 301±45). Diameter and age was not related. Highest overall radial growth rate was estimated as 15±18 years/cm. Soil variables were basic in reaction, free from salinity, calcareous in nature. No significant correlation was recorded between juniper tree density/ seedlings density and some of the soil variables. It is observed that the present degraded stage of the juniper forests in the study area might be due to anthropogenic disturbances, drought, poor soil conditions, mistletoe and fungal infections and effects of climatic change. It is also suggested that the present study will provide information to understand the current status, dynamics and the future trends of these forests.
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