A number of evidences confirm that the prevalence of asthma varies from place to place due to a v... more A number of evidences confirm that the prevalence of asthma varies from place to place due to a variety of factors. This study focuses on the vegetation and health concerns, and assesses the utility of Geographic Information Systems, to investigate the spatial correspondence ...
Currently normalized difference vegetation index (NDVI) is extensively used for appraise vegetati... more Currently normalized difference vegetation index (NDVI) is extensively used for appraise vegetation composition, structure, stratification and distribution. Spatial and temporal rainfall distribution and its effect on NDVI can be helpful for drought examining. This study has been done to improved comprehend this association. The response of vegetation growth to current climate change in Pakistan and adjoining south Asian countries (22–42°N, 60–80°E) were investigated by analyzing the time series of the NDVI maps. We also obtained and analyzed time series of different variable i.e. rainfall, soil moisture, evapotranspiration and soil temperature model data, through NASA Geospatial Interactive Online Visualization and analysis Infrastructure (Giovanni) system, during JanDec, 2014 for every three month interval. The NOAA Climate Prediction Center from International Research institute (IRI) for climate and society’s platform was also used for rainfall anomaly data. We found that NDVI va...
The present investigation focuses on quantitative description of moist temperate conifer forest v... more The present investigation focuses on quantitative description of moist temperate conifer forest vegetation. Forty-one stands of conifer dominating forests, throughout their natural range, were sampled by point-centered quarter method while associated understorey vegetation was sampled by circular plots (1.5 m radius) and relevant quantitative attributes calculated and described. In addition to vegetational sampling, topographic observations were also taken and described in relation to vegetation description and distribution. Out of the twelve tree species, five conifer species were common in moist temperate area of Pakistan, including Pinus wallichiana A.B. Jackson (average importance value = 46%), Abies pindrow Royle (43%), Cedrus deodara (Roxb.) G. Don. (49.6%), Picea smithiana (Wall.) Boiss. (25.2%) and Taxus fuana Nan Li & R.R. Mill. (6%). Among angiospermic trees, Juglans regia L. attained 9.25 % average importance value. Common understorey species were: Pteris cretica L., Rosa brunoni Lindl, Berberis lyceum Royal I.C., Hedera nepalensis K. Koch, Rubus biflorus Ham. ex Sm., Thymus serpyllum L., Rosa webbiana Wall. ex Royle, Rubus ellipticus Smith and seedlings of some tree species. Thirteen forest community types were recognized on the basis of dominance (importance value) and described in relation to associated topographic and climatic characteristics. The community types examined, in particular, correlated well with the biotemperature and precipitation.
Dendrochronological studies were conducted based on the data of 41 different mature stands of moi... more Dendrochronological studies were conducted based on the data of 41 different mature stands of moist temperate areas of southern Himalayan and Hindukush region of Pakistan. Wood samples as cores were obtained from 222 trees including those of Pinus wallichiana A.B. Jackson, Abies pindrow Royle, Cedrus deodara (Roxb.) G. Don., Picea smithiana (Wall.) Boiss., and Taxus fuana Nan Li & R.R. Mill., using an increment borer. Age and growth rates of these trees were estimated. Correlations were sought between the diameter / age, diameter / growth rate and age and growth rate on the basis individual stands and on an overall basis. More than 50% correlations were found to be significant. Relationship between the growth rate of dominant conifer species with environmental factors (soil nutrients, edaphic factors and topographic factors) was also sought. In general, they disclosed poor relationships. Growth rate of Abies pindrow showed weak correlation (p<0.1) with salinity, total dissolved salts and water holding capacity while that of Cedrus deodara also exhibited weak correlation (p<0.1) only with total nitrogen of soil. These significant correlations did not show any particular trend of growth and development of dominant conifer species and may be spurious. Pinus wallichiana is widely distributed species in the moist temperate area but its growth rate did not exhibit any relationship with the measured environmental variables. It is shown that largest tree, in terms of diameter, is not necessarily the oldest. Highest growth rate (1.7 ± 0.5 years/cm) was recorded for Pinus wallichiana while slowest growth rate (8.4 ± 0.7 years/cm) was recorded for Cedrus deodara
A number of evidences confirm that the prevalence of asthma varies from place to place due to a v... more A number of evidences confirm that the prevalence of asthma varies from place to place due to a variety of factors. This study focuses on the vegetation and health concerns, and assesses the utility of Geographic Information Systems, to investigate the spatial correspondence ...
Currently normalized difference vegetation index (NDVI) is extensively used for appraise vegetati... more Currently normalized difference vegetation index (NDVI) is extensively used for appraise vegetation composition, structure, stratification and distribution. Spatial and temporal rainfall distribution and its effect on NDVI can be helpful for drought examining. This study has been done to improved comprehend this association. The response of vegetation growth to current climate change in Pakistan and adjoining south Asian countries (22–42°N, 60–80°E) were investigated by analyzing the time series of the NDVI maps. We also obtained and analyzed time series of different variable i.e. rainfall, soil moisture, evapotranspiration and soil temperature model data, through NASA Geospatial Interactive Online Visualization and analysis Infrastructure (Giovanni) system, during JanDec, 2014 for every three month interval. The NOAA Climate Prediction Center from International Research institute (IRI) for climate and society’s platform was also used for rainfall anomaly data. We found that NDVI va...
The present investigation focuses on quantitative description of moist temperate conifer forest v... more The present investigation focuses on quantitative description of moist temperate conifer forest vegetation. Forty-one stands of conifer dominating forests, throughout their natural range, were sampled by point-centered quarter method while associated understorey vegetation was sampled by circular plots (1.5 m radius) and relevant quantitative attributes calculated and described. In addition to vegetational sampling, topographic observations were also taken and described in relation to vegetation description and distribution. Out of the twelve tree species, five conifer species were common in moist temperate area of Pakistan, including Pinus wallichiana A.B. Jackson (average importance value = 46%), Abies pindrow Royle (43%), Cedrus deodara (Roxb.) G. Don. (49.6%), Picea smithiana (Wall.) Boiss. (25.2%) and Taxus fuana Nan Li & R.R. Mill. (6%). Among angiospermic trees, Juglans regia L. attained 9.25 % average importance value. Common understorey species were: Pteris cretica L., Rosa brunoni Lindl, Berberis lyceum Royal I.C., Hedera nepalensis K. Koch, Rubus biflorus Ham. ex Sm., Thymus serpyllum L., Rosa webbiana Wall. ex Royle, Rubus ellipticus Smith and seedlings of some tree species. Thirteen forest community types were recognized on the basis of dominance (importance value) and described in relation to associated topographic and climatic characteristics. The community types examined, in particular, correlated well with the biotemperature and precipitation.
Dendrochronological studies were conducted based on the data of 41 different mature stands of moi... more Dendrochronological studies were conducted based on the data of 41 different mature stands of moist temperate areas of southern Himalayan and Hindukush region of Pakistan. Wood samples as cores were obtained from 222 trees including those of Pinus wallichiana A.B. Jackson, Abies pindrow Royle, Cedrus deodara (Roxb.) G. Don., Picea smithiana (Wall.) Boiss., and Taxus fuana Nan Li & R.R. Mill., using an increment borer. Age and growth rates of these trees were estimated. Correlations were sought between the diameter / age, diameter / growth rate and age and growth rate on the basis individual stands and on an overall basis. More than 50% correlations were found to be significant. Relationship between the growth rate of dominant conifer species with environmental factors (soil nutrients, edaphic factors and topographic factors) was also sought. In general, they disclosed poor relationships. Growth rate of Abies pindrow showed weak correlation (p<0.1) with salinity, total dissolved salts and water holding capacity while that of Cedrus deodara also exhibited weak correlation (p<0.1) only with total nitrogen of soil. These significant correlations did not show any particular trend of growth and development of dominant conifer species and may be spurious. Pinus wallichiana is widely distributed species in the moist temperate area but its growth rate did not exhibit any relationship with the measured environmental variables. It is shown that largest tree, in terms of diameter, is not necessarily the oldest. Highest growth rate (1.7 ± 0.5 years/cm) was recorded for Pinus wallichiana while slowest growth rate (8.4 ± 0.7 years/cm) was recorded for Cedrus deodara
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Papers by Imran Khan
stands of conifer dominating forests, throughout their natural range, were sampled by point-centered quarter method while
associated understorey vegetation was sampled by circular plots (1.5 m radius) and relevant quantitative attributes calculated
and described. In addition to vegetational sampling, topographic observations were also taken and described in relation to
vegetation description and distribution. Out of the twelve tree species, five conifer species were common in moist temperate
area of Pakistan, including Pinus wallichiana A.B. Jackson (average importance value = 46%), Abies pindrow Royle (43%),
Cedrus deodara (Roxb.) G. Don. (49.6%), Picea smithiana (Wall.) Boiss. (25.2%) and Taxus fuana Nan Li & R.R. Mill.
(6%). Among angiospermic trees, Juglans regia L. attained 9.25 % average importance value. Common understorey species
were: Pteris cretica L., Rosa brunoni Lindl, Berberis lyceum Royal I.C., Hedera nepalensis K. Koch, Rubus biflorus Ham.
ex Sm., Thymus serpyllum L., Rosa webbiana Wall. ex Royle, Rubus ellipticus Smith and seedlings of some tree species.
Thirteen forest community types were recognized on the basis of dominance (importance value) and described in relation to
associated topographic and climatic characteristics. The community types examined, in particular, correlated well with the biotemperature and precipitation.
of southern Himalayan and Hindukush region of Pakistan. Wood samples as cores were obtained from 222 trees including
those of Pinus wallichiana A.B. Jackson, Abies pindrow Royle, Cedrus deodara (Roxb.) G. Don., Picea smithiana (Wall.)
Boiss., and Taxus fuana Nan Li & R.R. Mill., using an increment borer. Age and growth rates of these trees were estimated.
Correlations were sought between the diameter / age, diameter / growth rate and age and growth rate on the basis individual
stands and on an overall basis. More than 50% correlations were found to be significant. Relationship between the growth
rate of dominant conifer species with environmental factors (soil nutrients, edaphic factors and topographic factors) was also
sought. In general, they disclosed poor relationships. Growth rate of Abies pindrow showed weak correlation (p<0.1) with
salinity, total dissolved salts and water holding capacity while that of Cedrus deodara also exhibited weak correlation
(p<0.1) only with total nitrogen of soil. These significant correlations did not show any particular trend of growth and
development of dominant conifer species and may be spurious. Pinus wallichiana is widely distributed species in the moist
temperate area but its growth rate did not exhibit any relationship with the measured environmental variables. It is shown
that largest tree, in terms of diameter, is not necessarily the oldest. Highest growth rate (1.7 ± 0.5 years/cm) was recorded for Pinus wallichiana while slowest growth rate (8.4 ± 0.7 years/cm) was recorded for Cedrus deodara
stands of conifer dominating forests, throughout their natural range, were sampled by point-centered quarter method while
associated understorey vegetation was sampled by circular plots (1.5 m radius) and relevant quantitative attributes calculated
and described. In addition to vegetational sampling, topographic observations were also taken and described in relation to
vegetation description and distribution. Out of the twelve tree species, five conifer species were common in moist temperate
area of Pakistan, including Pinus wallichiana A.B. Jackson (average importance value = 46%), Abies pindrow Royle (43%),
Cedrus deodara (Roxb.) G. Don. (49.6%), Picea smithiana (Wall.) Boiss. (25.2%) and Taxus fuana Nan Li & R.R. Mill.
(6%). Among angiospermic trees, Juglans regia L. attained 9.25 % average importance value. Common understorey species
were: Pteris cretica L., Rosa brunoni Lindl, Berberis lyceum Royal I.C., Hedera nepalensis K. Koch, Rubus biflorus Ham.
ex Sm., Thymus serpyllum L., Rosa webbiana Wall. ex Royle, Rubus ellipticus Smith and seedlings of some tree species.
Thirteen forest community types were recognized on the basis of dominance (importance value) and described in relation to
associated topographic and climatic characteristics. The community types examined, in particular, correlated well with the biotemperature and precipitation.
of southern Himalayan and Hindukush region of Pakistan. Wood samples as cores were obtained from 222 trees including
those of Pinus wallichiana A.B. Jackson, Abies pindrow Royle, Cedrus deodara (Roxb.) G. Don., Picea smithiana (Wall.)
Boiss., and Taxus fuana Nan Li & R.R. Mill., using an increment borer. Age and growth rates of these trees were estimated.
Correlations were sought between the diameter / age, diameter / growth rate and age and growth rate on the basis individual
stands and on an overall basis. More than 50% correlations were found to be significant. Relationship between the growth
rate of dominant conifer species with environmental factors (soil nutrients, edaphic factors and topographic factors) was also
sought. In general, they disclosed poor relationships. Growth rate of Abies pindrow showed weak correlation (p<0.1) with
salinity, total dissolved salts and water holding capacity while that of Cedrus deodara also exhibited weak correlation
(p<0.1) only with total nitrogen of soil. These significant correlations did not show any particular trend of growth and
development of dominant conifer species and may be spurious. Pinus wallichiana is widely distributed species in the moist
temperate area but its growth rate did not exhibit any relationship with the measured environmental variables. It is shown
that largest tree, in terms of diameter, is not necessarily the oldest. Highest growth rate (1.7 ± 0.5 years/cm) was recorded for Pinus wallichiana while slowest growth rate (8.4 ± 0.7 years/cm) was recorded for Cedrus deodara