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SPECIES AND COMMUNITY DIVERSITY OF VASCULAR FLORA ALONG
ENVIRONMENTAL GRADIENT IN NARAN VALLEY: A MULTIVARIATE
APPROACH THROUGH INDICATOR SPECIES ANALYSIS
SHUJAUL
MULK KHAN1*,
DAVID
HARPER1,
SUE
PAGE2
AND HABIB AHMAD3
Abstract:
Quantitative and qualitative characteristics of floristic diversity at
species level along environmental gradients were measured using a
randomly stratified design for identifying major plant communities of
Narran Valley, Pakistan. Data was collected at 144 sampling stations
along 24 altitudinal transects, 12 each at southern and northern
aspects. Altitudinal range transects was within the limits of 2450 to
4100 masl. Some 198 species belonging to 68 families were indentified
along transects. The Two Way Cluster Analysis (TWCA) and Indicator
Species Analysis (ISA) recognized 5 plant communities with significant
indicator species. The communities generally showed an
elevation-latitudinal gradient complex from inclined, mesic-cool
temperate vegetation of Phenerophytes and Chamaephytes, to more dry cold
subalpine and alpine herbaceous vegetation of Cryptophytes and
Therophytes. ISA analysis revealed that the mountain aspect, altitude
from the sea level and soil depth were the strongest environmental
variables (p ≤ 0.05) for determining the community structure. Species
diversity was optimum at the middle altitudes (2800-3400 masl) as
compared to either the lower or higher altitudes. Herbaceous vegetation
had positive correlation with altitude as a function of
eco-physiological pressures as generally observed on like other highly
elevated peaks Himalayas.
1Department of Biology, University of Leicester, UK,
2Department
of Geography, University of Leicester, UK
3Department of Botany, Hazara University Mansehra, Pakistan,
*E-mail
of the corresponding author:
shuja60@gmail.com
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