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Phytosociology, structure and dynamics of Pinus roxburghii associations from Northern Pakistan

Journal of Forestry Research 2014年第3期25卷 511-521页

作者： Nasrullah Khan kishwar ali Shahid Shaukat Laboratory of Plant Ecology and Department of Botany University of Malakand Chakdara Department of Plant Sciences School of Biological Sciences University of Reading Department of Botany Federal Urdu University

We investigated the phytosociology, structure and dynamics of Pinus roxburghii in 40 stands in northern areas of Pakistan by using cluster analysis （Ward’s agglomerative clustering） and ordination （Non-metric Multidimensional Scaling）. Cluster analysis revealed three major groups associated with specific environmental characteristics：（1） P. roxburghii （2） Pinus-Quercus baloot and （3） Pinus-Olea ferruginea community types. NMS-ordination showed the major gradient as an amalgam of elevation （r2=0.441, p＆lt;0.01） and slope （r2=0.391, p＆lt;0.05） as the two topographic factors correlated with species distribution. The first ordination axis also showed positive correlation with soil variables like pH and electrical conductivity, suggesting that soil chemistry was related to topographic characteristics and probably acted as a secondary gradient. We also examined size class distributions, age structures and growth rates of the three communities in order to describe community development and dynamics. Total tree density was 14700 plants/ha, with P. roxburghii having a relative density of 82%to 100%. Density of juve-nile and total density and basal area of the subordinate tree species were low. The low density of trees in the smallest diameter size-class sug-gested that the recruitment of small P. roxburghii plants into the adult population may be lower than the required replacement rate for the stands. Pooled size-class distributions for the species showed a multimo-dal pattern with some regeneration gaps. Browsing, heavy logging and＆amp;nbsp;other anthropogenic activities were the overriding factors responsible for the poor recruitment of P. roxburghii. We concluded from the age struc-ture that the forests were characterized by the dominance of young trees. Growth rate analysis revealed that P. roxburghii was the fastest growing species among the conifers species in Pakistan. In view of its relatively fast growth and longevity, P. roxburghii seems to be a suitable choice f

关键词： phytosociology structure dynamics multivariate techniques,dendrochronology Himalayan range

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Composition,Structure and Regeneration Dynamics of Olea ferruginea Royle Forests from Hindukush Range of Pakistan

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Journal of Mountain Science 2015年第3期12卷 647-658页

作者： NASRULLAH Khan FAYAZ ali kishwar ali SHAHID Shaukat Laboratory of Plant Ecology Department of Botany University of Malakand Department of Plant Sciences School of Biological SciencesUniversity of Reading Institute of Environmental Studies University of Karachi

Abstract＂ The abundance of Olea ferruginea in Malakand Division has been significantly reduced across its distribution range due to anthropogenic pressure in the recent past. A number of initiatives were taken for grafting this species to obtain better seeds for oil production, without the basic information on their ecology and management. To address this knowledge gap, we quantified the composition, structure and regeneration dynamics of Olea ferruginea forests in Malakand Division, Hindukush range of Pakistan. In the present study, five communities dominated by Oleaferruginea were identified using Ward＇s agglomerative cluster analysis. Total tree density ranged from 153-26o2 plants/ha, and basal area from 19.55 to 2353 m~ ha-1 with Olea having a relative density of 51% to 87% and basal area of 48% to 93%, respectively. The density of juveniles of the dominant and subordinate tree species were generally low which reflect their narrow distribution in the study area. Size-class distributions of O. ferruginea disclosed a bell-shaped pattern, indicating that forests were heavily exploited by local inhabitants in previous periods and recently by armed forces owing to security risks in the study area. The age （mean max. 300±34 years） and annual increment （3.2±1.2 years/cm） indicates that the species is long lived and generally slow growing among the different broad leaved species studied so far. However, the oldest trees can be found by the exploration of large diameter trees in the area. In addition, we found a stable linear relationship between the age and diameter （r2 = o.779）, indicating that diameter is a good predictor of age for this broad leaved species. In view of its relatively slow growth, longevity and positive ring-width characteristics O. ferruginea seems to be a suitable choice for dendroecological and dendrochronological studies in lesser Himalayan and Hindukush ranges of Pakistan. The results obtained from this study may help in understanding the composi

关键词： Oleaferruginea Species composition Ward's agglomerative cluster analysis Seedling Dendroecology

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Future of Abies pindrow in Swat district,northern Pakistan

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Journal of Forestry Research 2014年第1期25卷 211-214页

作者： kishwar ali Habib Ahmad Nasrullah Khan Stephen Jury Department of Plant Sciences School of Biological SciencesUniversity of Reading Department of Genetics Hazara University Mansehra Laboratory of Plant Ecology and Department of Botany University of Malakand Chakdara

Swat district is a biodiversity hub of Pakistan. The plant species, especially trees, in the Swat District are exposed to extinction threat from global climate change. Maximum entropy （MaxEnt） modelling of species distribution, using HADCM3 A2a global climate change scenario, pre-dicted a considerable change in the future distribution ofAbies pindrow （Royle ex ***） Royle. AUC （area under the curve）values of 0.972 and 0.983 were significant for the present and future distribution models of the species, respectively. It is clear that bioclimatic variables such as the mean temperature of the warmest quarter （bio_10） and the annual temperature range （bio_7） contribute significantly to the model and thus affect the predicted distribution and density of the species. The future model predicts that by the year 2080 population density will have decreased significantly. The highest density of the species is recorded in the eastern and western borders of the Valley in the areas of Sulatanr and Mankial. The changes in density and distribution of the species can have considerable impact, not only on the tree species itself, but on the associated subflora as well.

关键词： Vegetation mapping Abies pindrow climate change predictive models Swat Valley

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Vegetation-environment relationship in Pinus wallichiana forests of the Swat Hindukush range of Pakistan

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Journal of Forestry Research 2020年第1期31卷 185-195页

作者： Inayat Ur Rahman Nasrullah Khan kishwar ali Siraj Ahmad Laboratory of Plant Ecology and Dendrochronology Department of BotanyUniversity of Malakand

Understanding the influence of environmental variables on the spatial distribution of ecological communities is essential to predict the response of vegetation to various environmental *** theory suggests that multiple environmental factors shape local species assemblages and should influence the various components of community structure and composition in different *** study aimed to classify Pinus wallichiana dominated forests in the Swat Hindukush range mountains to understand the relative influence of multiple environmental filters on its composition and *** forests represent the most typical of the species distribution in northern Pakistan and were not subjected to any phytosociological *** this purpose,thirty forest stands,spanning a wide range of physical habitats were sampled using 10 x 10 m plots and the importance value index was *** floristic and environmental data were subjected to Ward’s agglomerative cluster analysis for objective classification and ordinated with NMS ordination for pattern description and testing the vegetation-environmental *** floristically and ecologically distinct communities were recognized along the topographic gradient(elevation,r=0.377;slope,r=0.5548) coupled with soil physical(clay,r=0.2782;silt,r=0.3225) and chemical properties(pH,r=0.4975;lime,r=3982).An elevation gradient of 100 m separated the low(Pinus wallichiana-Quercus dilatata community)and middle elevations forest stands(*** pure population) from the highland population type(Pinus wallichiana-Cedrus deodara community).The floristics and structure of these forest types respond directly or indirectly to topographic and soil variables which were evidenced from the floristic composition,species richness,and community *** characteristics of the communities changed from heterogenous,dense stands to sparsely dispersed conifers,broadleaved-evergreen,and deciduous vegetation types along

关键词： Blue pine forests Classification-ordination Ecological gradient Hindukush range mountains Species composition

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