Syed Mukaram Shah, from
the institute of Pakistan. Farrukh Hussain, from the institute
of Pakistan and Musharaf Khan, from the institute of Pakistan. wrote
a Research article about, Growth, Sex Ratio & Fruit Yield of Juniperus
excelsa in Mastuj Valley. Entitled, Growth behaviour, sex ratio and fruit
output of Juniperus excelsa in Mastuj valley, District Chitral, Khyber
Pakhtunkhawa, Pakistan. This research paper published by the International Journal of Biosciences | IJB. an open access scholarly research journal
Biosciences. under the affiliation of the International Network For
Natural Sciences| INNSpub. an open access multidisciplinary research
journal publisher.
Abstract
Study was conducted to
examine growth behaviour, sex ratio and seed output of Juniperus excelsa in
various parts of Mastuj valley, Khyber Pakhtunkhawa Pakistan. Average height,
diameter and density of male, female and bisexual plants were determined. Seed
output of female plants were found highest in Dodorghaz gol followed by Mastuj
village and Ghuru gol. Number of fallen fruits were high in Dodorghaz gol
followed by Mastuj village and Ghuru gol. Number of seedlings were high in
Mastuj village followed by Ghuru gol and Dodorghaz gol. Soils were sandy loam
and loamy sand with elements such as C, Ca, Mg, Si, Fe and K. These results
strongly sustain genetically-determined sex ratios and a lack of major
differences between males and females in growth behaviour and seed output which
had been suggested by short-term studies elsewhere in the species’ range.
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Introduction
Mastuj lies in between
36◦-3′ north latitude and 72◦-5′ east longitude towards the northeastern part
of District Chitral bordering Northern areas and Afghanistan. The altitude of
the area vary from 2200m-4000m. Climatically the area falls within dry
temperate zone with mild summers and cold winters with snowfall.
Topographically the area is bounded by mountains having scattered Juniperus
forests. Ahmed et al (1990) sampled 60 monospecific stands of Juniperus excelsa
at four locations in Balochistan and recorded density, basal area and height of
individual. Soils were analysed for selected physical and chemical
characteristics and the degree of disturbance due to logging and burning was
also noted. Fisher and Gardner (1994) described the status and ecology of a
Juniperus excelsa subsp. Polycarpos woodland in the northern mountains of Oman.
Sarangzai (2000) described the population structure and natural regeneration
potential of Juniperus excelsa in the northern Balochistan. Gauquelin et al
(2002) studied the sex ratio and sexual dimorphism in Juniperus thurifera. Ali
(2003) discussed issues and threats to Juniper forests in Chitral and provided
recommendations for the conservation of these forests to avoid further
degradation. Dar and Christensen (2003) recognized seven texa of Juniperus from
the western Himalaya. Schulz et al (2003) studied cone morphology in Juniperus
in the light of cone evolution in cupressaceae. Borghesio et al (2004)
evaluated the conservation status of two Juniperus forests in south Ethiopia.
Auken et al (2005) examined the emergence, mortality and growth of Juniperus
ashei. Short term studies of J. virginiana in Ontario (Vasiliauskas and
Aarssen, 1992) and in Alabama (Lawton and Cothran 2000) have shown a lack of
major differences between males and females in growth rates, growth behaviour,
sex ratio and seed output and suggested that the genetically-determined sex
ratio was 1:1. However, it was not possible in those studies to determine the
long-term survivorship of marked individuals and the effect that it may have
had on the observed sex ratio, growth rates and growth behaviour. There have
been frequent reports of inconstant sex expression in Juniperus species (Vasek
1966, Freeman et al. 1981, Lloyd and Bawa 1984, Jordano 1991), but there have
been no long-term observations on the sex expression of juniperus excelsa
individuals in natural populations. The objective of this research was to
utilize long-term observations on associates of labeled individuals of
juniperus excelsa to directly determine growth rates, growth behaviour, sex
ratio and seed output of individual males, females and bisexual, constancy of
sex expression, and resulting sex ratios.
Reference
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