The tree species diverseness, distribution and anthropogenetic perturbations along the altitudinal gradients were evaluated in Bhutan ‘s Jigme Singye Wangchuck National Park located in interior Himalayas. The thin information of works species where direction claims high precedence to species preservation necessitated this survey. The research involved 92 forest stock list sample secret plans covering 3.68 hour angle in the park which was conducted along altitudinal gradients across four sites where each site covered 23 sampled secret plans. In the sampled secret plans the perturbation governments were besides registered and the base construction and diverseness of tree species were evaluated capable to different perturbation strengths. Consequence showed the sum of 1276 persons and 144 species belonging to 59 households. Altitude was significantly associated to species distributions and diverseness. Stand construction and species profusion was significantly different in extremely disturbed sampled secret plans while no important differences is detected between the no recorded human perturbations, low perturbations and reasonably disturbed sampled secret plans. Based on our consequences we concluded that environment dramas of import function in determining forest resources status in the park and we suggest that moderate perturbations may non necessitate the direction scheme to except the human activities despite the use of forest resources in JSWNP. However, activities that leads to higher activities may necessitate to integrate sustainable long term scheme that guarantees the sustainable supports of the park people and the preservation of its ain interest.
Biodiversity is indispensable for economic and aesthetic well-being to worlds and stableness for proper operation of the ecosystem ( MEA, 2000 ; Singh, 2002 ; Sagar et al. , 2003 ) . Interest in biodiversity preservation has presently raised issues runing from direct anthropogenetic perturbations to indirect such as clime alteration taking to extinction of species ( Ehrlich and Wilson, 1991 ; Markham, 1996 ; MCneely, 1994 ; Sodhi et al. , 2004 ) . Many sorts of environmental alterations influence the diverseness of species. Therefore, preservation of biodiversity is instead one of the notable issues that require important scientific attempts required to understand this complex phenomenon. Biodiversity preservation, peculiarly forest protection with quantification of forest species diverseness is an of import facet that, provides resources and home grounds for many other species ( Cannon et al, 1998 ; Sagar et Al, 2003 ; Yadav and Gupta, 2006 ) . The turning environmental alteration augmented by human perturbations would happen as hurtful effects on the floristic constructions that might hold wider deductions on ecosystem ( Rai, 1985 ; Sheil, 1999 ) . But to understand this phenomenon from Himalayan ecosystem sing species diverseness and human perturbations is limited. In Bhutan, although more than 50 % of the state ‘s country is under protected system, the floristic diverseness and the human impacts on floristic diverseness due to resources usage by local people in the interior Himalayan ecosystem is missing.
A figure of factors affect the construction, distribution and composing of woody species. The factors could be climate, substrate, topography, natural or human perturbations. In comparatively little graduated tables soil chemical science ( Fu et al. , 2004 ) , topography ( Gould et al. , 2006 ; Yadav and Gupta, 2006 ) , canopy spreads and human perturbations such as farm animal graze, cutting and firing ( Lapkern et al. , 2009 ; Sapkota et al. , 2009 ; Thapa and Chapman, 2010 ) are the of import factors that affects community construction, profusion and diverseness. At a larger graduated table, such as landscapes, clime and lift ( 2001 ; Gould et al. , 2006 ; Zhao et al. , 2009 ) could play a important function in finding species profusion, diverseness and construction.
In the semitropical prohibitionist and warm temperate wood, the available wet plays of import function to species distributions. Elevation, facet, incline and dirt chemical science are the other determiners of local species composing ( Yadav and Gupta, 2006 ; Cielo-Filho et al. , 2007 ) . On the other manus, perturbations be it natural or homo could change the construction of the ecosystem and available resources ( Lindemeyer and Franklin, 2002 ; Zhu and Liu, 2004 cited in Zhu et al. , 2007 ) . Writers argue that the human perturbation could be more destructive than any other natural factors, peculiarly, with respect to stand construction and composing of wood ( ibid ) , nevertheless, our position is that the impacts of human perturbations on biodiversity could depend on the strength of perturbations. Some surveies from Himalayan ecosystem reported the varied perturbations impacts based on the strength of perturbations ( Sagar et al. , 2003 ; Sapkota et al. , 2009 ) .
Many others argue that species diverseness is frequently higher when the perturbation is intermediate strength or frequence ( Collins et al. , 1995 ; Zhu et al. , 2004 ; Zhao et al. , 2009 ) . For case, Collins et al. , ( 1995 ) concluded that perturbation of a suited strength increases the species profusion and that agrees with the Intermediate perturbation hypothesis of Connell ( 1978 ) . However, intensive and drawn-out human perturbations may take to worsen in species diverseness and alteration in species composition finally taking to forest debasement ( Ramirez-marcial et al. , 2001 ; Sagar et al. , 2003 ; Sagar and Singh, 2004 ) . Therefore, the relationship between the perturbation and diverseness has received more attending from natural resource directors in the recent yesteryear ( Lindemeyer and Franklin, 2002 ; Zhu and Liu, 2004 ) . In forest direction, particularly in protected countries ( PAs ) like Bhutan it is necessary to see how human activities augmented with environmental factors affect tree construction and diverseness. When the diverseness and construction of woods are maintained despite the use by human, direction scheme may non necessitate the exclusion of human usage of forest resources.
In Bhutan the 72.5 % of the entire land country is covered by wood ( RGOB, 2002, 2003 ; Gurung, 2008 ) . About 52.0 % of the woods cover, out of the sum of 72.5 % , is represented by PAs and Jigme Singye National Park ( JSWNP ) represents approximately approximately 10 % of the entire proportion. JSWNP is the 3rd largest national park in Bhutan centrally located and screens sub-tropical, temperate to alpine zone lifting from 300 m in the South to 500 m in the North. Surveies by Ohsawa ( 1999 ) and Wangda and Ohsawa ( 2006 ) in Bhutan Himalaya, concluded that the laterality construction changed from multi-dominant to mono dominant community with addition in height. Wangda and Ohsawa ( 2006 ) besides concluded that the past perturbations lead to the uni-modal type of regeneration where as sporadic type of regeneration in instance of little graduated table perturbations. However there is small information sing the environment, forest relationship every bit good as forest people interactions from the national Parkss in Bhutan.
In JSWNP switching cultivation, aggregation of wood merchandises and associated farm animal croping were extremely practiced by local people to supplement their subsistence based supports ( Siebert et al. , 2008 ) . The presence of occupants in the park and their close linkages with natural resources are a beginning of struggles. Past research in the JSWNP was concerned chiefly with human-wildlife struggles and attitudes of local people related to this job ( Wang and Macdonald, 2006, Wang et al 2006a, Wang et al 2006b ) . The local ‘s subsistence based supports is farther constrained by the preservation policy that restricts forest merchandises use ( Wang et al. , 2006a ) . In add-on the preservation activities in the park are in recoil since 2006 due to the fiscal crisis as donor financess dry up ( Kuenselonline, 2009 ) . At this interest, how local people adjust with the turning restraints to their supports is a great concern. JSWNP has been selected for this research because it is a flagship country for preservation owing to its location, geographical fluctuations and presence of high diverseness of works species claimed to hold medicative and economic importance ( RGOB, 2002 ) . There are turning literatures sing the preservation and factors associated with the anthropogenetic perturbation from the people populating in and around the Parkss and elsewhere. The surveies sing socio-economic position, their support options, forest resources use, bio-physical conditions of forest resources and the preservation schemes are highly of import for pulling sustainable direction scheme. However, there is really thin information sing the tree diverseness, distributions and their relationships to anthropogenetic perturbations and environmental variables. The deficiency of information sing the impacts on forest resources by local communities through farm animal graze and aggregations of wood merchandises necessitated this research.
The aims of the present survey was to: ( 1 ) papers the floristic features and distributions forms in JSWNP, ( 2 ) assess the effects of environmental factors to corner species construction and composing, and ( 3 ) evaluate the different perturbation governments and their grades of perturbation on species composing. The item information sing diverseness and perturbation governments would supply the footing to find the nature and distributions of biodiversity resources of the part being managed. The information is really much necessity to put the preservation schemes in the national park like Bhutan where most of the local people are dependent on park resource. Has at that place been any quantitative flora studies done in this park before? If non, that is a reasonably good justification as good? ? ?
The survey country is located in cardinal Bhutan ( Fig.1 ) within the co-ordinates of 27012’N, 0900 08 ‘ Tocopherol, ( West ) , 270 26’N, 0900 23’E ( North ) , 270 15’N, 0900 35 ‘ E ( East ) , 270 02 ‘ N, 0900 20 ‘ E ( South ) ) with heights runing from 200~5000 m a.s.l. It is the 3rd largest national park of Bhutan and is spread over an country of 1723 sq km covering five Dzongkhags ( territories ) and 11 gewogs ( sub-districts ) .
Fig. 1.1 Location of JSWNP in Bhutan
The park comprises a assortment of home grounds with huge piece of lands of primary woods ; it is home to about 395 bird species, seven of which are listed among the globally endangered species. Park flora scopes from sub-tropical in the South to temperate and alpine in the North. Harmonizing to Ohsawa ( 1987 ) Bhutan is divided into six bunchs of altitudinal sections and in six bunchs five flora zones are identified. The flora zones are based on the similarity in floristic composing and dominant species ( Table 1.1 ) . These woods are largely undisturbed owing to its geographical location within the Inner Himalayas ( Ohsawa, 1987 ) .
Table 1.1: Description of flora boundary in Bhutan
& lt ; 1000 m
Sub-tropical/ Warm -temperate
Beginning: Ohsawa, M. ( ed. ) Life Zone Ecology of Bhutan Himalaya, 1987.
A quantitative flora study was carried out in JSWNP from June 2008 to November 2008 and 100 sample secret plans were surveyed indiscriminately running along the altitudinal gradients. We used Arcview GIS version 3.3 package to bring forth maps and for the sample secret plans to be surveyed was indiscriminately generated based on the co-ordinates obtained from the map. During the study, sample secret plans were determined utilizing GPS ( Global Positioning System ) with an interval of 100 m along the altitudinal gradients. In instance of unaccessible secret plans such as secret plans located at drops and stone out harvests sample secret plans were shifted from left to compensate or from top to bottom by 50 m. Field probes were carried out along the altitudinal gradients at four sites ; Ada-Pataley, Dovan-Jigmechhoeling, Korphu-Trong and Tangsibji-Langthel. The determination to take four transects were based on the geographical apparatus or landforms observed during reconnaissance study.
For the arboreal bed, woody persons of all tree species with diameter at chest tallness ( dbh ) larger than 10 centimeter, tree tallness utilizing SUNTOO clinometers, canopy coverage utilizing hypsometer were recorded within each sample secret plan of 20m X 20m quadrates. Vegetation crown screen was estimated utilizing per centums graduated tables. For the bush all the woody persons with dbh smaller than 10 centimeters and bigger than 2.5 centimeters were measured. The herbaceous stratum were counted based on the species occurred. The size of the sub-plots for bush and herbaceous stratum were determined as 5m X 5m and 1m Ten 1m sapling secret plans nested within the trying secret plans for trees. For designation of species the terminology followed Flora of Bhutan ( Grierson and Long, 1983-2001 ) , Flowers of the Himalaya ( Polunin and Stainton, 1984, 1997 ; Gardner et al. , 2000 ; Manandhar, 2002 ) .
In each secret plan and sub-plot the place was determined by GPS and several environmental factors were recorded such as ; lift, incline, slope way, Slope place, dirt deepness of upper skyline ( A ) and soil deepness of lower skyline ( B ) . The incline way ( E, S, W, N, NE, SE, SW, and NW ) and slope place ( runing from 0-5 from pes to the top of mountain ) were recorded as categorical variables ( Zhu et al. , 2007 ; Zhao et al. , 2009 ) .
The effects of perturbations on the works diverseness were evaluated based on the ocular observations noted along the lift gradients at the sample secret plans. Prior to the start of the stock list, we discussed the anthropogenic every bit good as natural perturbations with local wood users. All the woods in the interior Himalaya are subjected to natural or anthropogenetic perturbations governments which are of changing strengths. They are natural and anthropogenetic or both. The natural perturbations include landslides, dirt eroding and temblors. The anthropogenetic perturbation classs were defined as: deforestation, graze, lopping of tree subdivisions for fresh fish and fuel wood, remotion of foliage and wood litter from the forest floor. Although both types of perturbations affect ecosystem stableness and retard the sequence procedure ( Todaria et al. , 2010 ) but for the intent of this research merely anthropogenetic perturbations were taken into history. The anthropogenetic perturbations ( Rao et al. , 1990 ; Veetas, 1997 ; Sagar et al. , 2003 ) such as “ discerping for fuel wood and fresh fish, combustion, farm animal graze, aggregation of assorted merchandises such as forest floor biomass, fruits, fibres and medicative workss ” and switching cultivation and perturbation strength were registered along the lift gradient. Based on the ocular review of the indexs, we calculated a perturbation Impact Factor ( DIF ) as the entire appraisal ( Sagar et al. , 2003 ; Sapkota et al. , 2009 ) .
The perturbation and perturbation strength were registered along the lift gradient. The perturbation indexs were recorded in comparative footings as undisturbed ( UD ) ; low disturbed ( LD ) ; reasonably disturbed ( MD ) and extremely disturbed ( HD ) ( values runing from 0 to 3 ) . The perturbation index was described as the ratio of the peculiar index to sum of all the indexs in sampled secret plans ( Zhao et al, 2009 ) .
The Importance Value Index ( IVI ) was calculated which is defined as the amount of the comparative denseness, comparative frequence and comparative laterality following Curtis and Mcintosh, 1951 ; cited in Kent and Coker, 1995. We calculated Basal Area ( BA ) from DBH ( Diameter at Breast Height ) of the species and summed up the BA. The per centum proportion of each species were calculated as comparative Basal Area per centum ( RBA % ) . We used calculated RBA to find species Dominance step ( Ohsawa, 1984 ) . The site degree analysis was besides assessed to find the dominant and co-dominant species of each site were performed on the footing of comparative basal screen. This method followed the Sagar et al. , ( 2003 ) with “ the species holding highest comparative basal screen was defined as dominant and that holding the 2nd highest comparative basal screen was defined as co-dominant species ” .
The Shannon diverseness index ( H ‘ ) was calculated for each secret plan utilizing the undermentioned equation ( Magurran, 1998 ) .
where PiA is the proportion copiousness of ith species of each species in the sample and S equals the entire figure of species in the sampling secret plan.
The species distribution and their relationship to environmental variables in JSWNP were analyzed utilizing Canonic Correspondence Analysis ( CCA ) ordination and generated diagrams utilizing CANODRAW 4.5. CCA measures the relationship between the environmental and species informations, which is a signifier of direct gradient analysis, and is more appropriate for surveies that focuses on analyzing the relationships between floristic composings constrained by environmental variables ( Leps and Smilauer, 2003 ) .
The Mann-Whitney U trial used to compare the each possible independent forest brace to place the differences in the average dbh of tree species between the disturbed secret plans and undisturbed secret plans ( Siegel, 1956 cited in Ramirez-Marcial, 2001 ; Sapkota et al. , 2009 ) .
1400 persons of trees with dbh & gt ; 10 centimeter and 533 persons of bush and saplings & gt ; 2.5 centimeter of dbh. Entire species 152 recorded from 4.335 hour angle sampled country.
Dominance ( Cm2 ha-1 )
The IVI of the flora was analyzed harmonizing to the boundaries following Ohsawa, 1987.
Altitude ( m )
Sub-tropical/ Warm -temperate
Tree Species Composition in JSWNP
Consequences from our field study in four sites in a sum of 92 forest stock list secret plans yielded a sum of 1276 roots, 144 species and 59 households ( Table 1.2 ) . The highest denseness of roots is found in Ada-Pataley site and the least in Korphu – Trong site. The highest diverseness is recorded from Dovan – Jigmechhoeling site although there is non much fluctuation in the diverseness of species across sites.
On the footing of comparative basal screen, the four sites differed in the combination of dominant and co-dominant species. Ada-Pataley site exhibited Pinus roxburghii as the dominant and Albizzia lebbeck as the co-dominant species. The of import Value Index ( IVI ) besides showed Pinus roxburghii as the most of import species, while at Dovan – Jigmechhoeling site Castanopsis hystrix is the dominant and most of import species and Ostodes paniculatus showed as co-dominant species. In Korphu – Trong site Lithocarpus elegans is the dominant where as Quercus lanata is the co-dominant species. The IVI analysis showed Litsea monopetala and Castanopsis tribuloides as the most of import species at Korphu – Trong site. In Tangsibji – Langthel site Pinus wallichii exhibited dominant and most of import species and Quercus lamellosa exhibited co-dominant species.
Overall analysis showed, Pinus wallichii, Pinus roxburghii and Castanopsis hystrix as the three most dominant and most of import species in JSWNP. Thus, the site wise analysis indicated the different community associations. For e.g ; Ada-Pataley site exhibited Pinus – Albizzia community ; Dovan – Jigmechhoeling site represented Castanopsis-Ostodes community ; Korphu – Trong site represented Lithocarpus-Quercus community while that at Tangsibji-Langthel exhibited Pinus-Quercus community.
Table 1.2 Tree species construction sum-up of four sites in JSWNP
No of sampled secret plans
Entire Stem count ( a‰?10 centimeter DBH )
No of species ha-1
No of households ha-1
Entire Mean DBH ( centimeter )
Density ( no of persons ha-1 )
Average tallness ( m )
Mean Basal Area ( m2/ha-1 )
Simpson ‘s Index ( D )
Shannon Index ( H )
Structural features of tree species in JSWNP
Consequences showed about 34.2 % of the trees with dbh category 15.1 to 25.0 centimeter and included maximal trees in this category ( non shown in tabular array ) . The highest figure of persons with a dbh scope of 15.1 to 25 centimeter was found in Ada-Pataley site ( about 13 % ) while Korphu – Trong and Tangsibji-Langthel site showed least per centum of trees within the dbh scope of 35.1 to 45.0 centimeter. Similarly, maximal trees were represented in the height scope of 5.1 m to 10.0 m with 35.7 % of the entire trees. Merely 5.7 % of the trees were represented in the height scope of less than five metres ( Table 1.3 ) .
Table 1.3 Height and dbh category for trees of four sites along the altitudinal gradients in JSWNP, Inner Himalayas, Bhutan. Percentage of the entire figure of persons of trees in parenthesis
Height ( m )
& lt ; 5
& gt ; 20.1
dbh ( centimeter )
Frequency ( Internet Explorers )
& lt ; 15
65 ( 5.1 )
161 ( 12.6 )
50 ( 3.9 )
41 ( 3.2 )
& gt ; 45.0
47 ( 3.7 )
364 ( 28.5 )
& lt ; 15
42 ( 3.3 )
112 ( 8.8 )
75 ( 5.9 )
35 ( 2.7 )
& gt ; 45.0
71 ( 5.6 )
335 ( 26.3 )
& lt ; 15
39 ( 3.1 )
74 ( 5.8 )
53 ( 4.2 )
30 ( 2.4 )
& gt ; 45.0
76 ( 6.0 )
272 ( 21.3 )
& lt ; 15
62 ( 4.9 )
90 ( 7.1 )
89 ( 7.0 )
30 ( 2.4 )
& gt ; 45.0
34 ( 2.4 )
305 ( 23.9 )
73 ( 5.7 )
456 ( 35.7 )
372 ( 29.2 )
202 ( 15.8 )
173 ( 13.6 )
Speciess distributions and impact of environmental factors
The consequences of the direct gradient analysis ( CCA ) showed that there is consecutive lessening in the characteristic root of a square matrixs along the first four axes. The characteristic root of a square matrixs for the first axis showed highest value, which indicates that, the representation of first axis with highest proportion of the species composing and distribution as a map of environmental factors ( Table 1.4 ) . The CCA showed a low cumulative per centum discrepancy of species informations that was explained on the first two CCA axes ( Table 1.4 ) . However, the species -environment correlativity was higher for the first two canonical axes ( 0.967 and 0.831 ) , which indicates a strong influence of environmental factors to species composing and distribution. The i¬?rst axis explained about 31 % of the discrepancy of species-environment relationship, and the 2nd about 13 % . The Monte Carlo trial showed high association between lift and species distributions ( P & lt ; 0.01 ) .
In the Intra-set correlativity of the environmental factors, the first axis was positively correlated with Elevation, dirt deepness A and Carbon content of the dirt. The 2nd and the 4th axis were negatively correlated with secret plan location. Similarly, 3rd axis was positively correlated with secret plan incline but negatively correlated with deepness of the top dirt and secret plan facet. Fourth axes showed negatively correlated with deepness of the top dirt. Therefore, lift was the most of import environmental factors and played of import function in species composing and distribution, followed by dirt deepness, Carbon content and secret plan location.
Based on the CCA ordination diagram the species were divided into four groups ( Fig 1.2 ) . The group I included some of the species such as Persea clarkeana, Aesculus glabra. , Acer hookeri, Viburnum erubescens and others showed positive correlativities to depth of the top dirt ( A ) . Group II included some of the species with positive correlativities to the ratio of dirt Calcium and Magnesium and the species include Garcinia pedunculata, Juglans regia, Sloanea dasycarpa, Eugenia Taiwan and others. Group III species showed negative correlativities lift and dirt deepness such as Eleocarpus lanceifolius, Ostodes paniculata, Pinus roxburghii and others and these species showed positive correlativities to plot incline because these species normally grow at the borders and steep inclines on the hills and besides at the steep inclines of the narrow vales. Group IV represents high lift vegetations such as Rhododendron botanical garden, Daphniphyllum himalayense, Lyonia ovalifolia, Quercus lamellosa and others ( Fig. 1.2 ) .
Fig. 1.2 The CCA ordination diagram for the influence of environmental gradient on species composing. Arrows represent the environmental factors and their lengths indicate the strength of the environmental consequence on species composing. Arrows to the right and left of the Y axis represent positive and negative correlativities respectively.In the fig 1.2 above merely the most correlative species are shown with inclusion regulations of 5 % through undertaking scenes in CANODRAW.
Table 1.4 The characteristic root of a square matrixs and intraset correlativities for CCA of the environmental factors
1 2 3 4 Entire inactiveness
Eigenvalues: 0.709 0.302 0.270 0.264 16.758
Species-environment correlativities: 0.967 0.831 0.835 0.808
Accumulative per centum discrepancy
of species informations: 4.2 6.0 7.6 9.2
of species-environment relation: 31.2 44.5 56.3 67.9
Sum of all characteristic root of a square matrixs 16.758
Sum of all canonical characteristic root of a square matrixs 2.275
Elevation ( m ) 0.978 -0.011 0.115 0.091
Soil depth A ( centimeter ) 0.540 0.112 -0.431 -0.694
Soil deepness B ( centimeter ) 0.465 -0.242 -0.378 -0.409
Calcium: Mg -0.011 0.333 0.365 -0.178
Carbon ( % ) 0.508 -0.305 -0.298 0.141
Aspect ( Category ) 0.075 0.238 -0.469 0.300
Plot Location ( Category ) -0.195 -0.546 0.211 -0.534
Slope ( grades ) -0.061 -0.050 0.492 -0.326
Tree species diverseness along the lift gradient
The Shannon Wiener Index ( H ‘ ) was calculated and illustrated against the lift gradient and the fluctuation showed bimodal curve and the peak value occurred along the lift zone centered around 1800 m a.s.l. ( Fig. 1.3 ) . The diverseness indices were lower after 500 m a.s.l.till about 1000 m a.s.l. and so once more showed lower diverseness around 1300 m a.s.l. so showed changeless lessening after 2100 m a.s.l.
Fig. 1.3. Relationship between the diverseness index ( H ‘ ) and the lift gradient.
Consequence of forest resources use by local people to species composing
During our family study, we asked local people to rank the forest resources based on the demand and penchant based on their day-to-day usage. Our purpose was to measure which among the forest merchandises are used largely in rural small towns inside the park and besides to measure which among the forest usage is associated most often to forest in the park ( Table 1.5 ) .
Table 1.5 Forest merchandise usage ranks by local people in JSWNP
Responses ( % )
Leaf litter and fresh fish
Weaving and basketry
Poles for fencing and supplication flags
*Total responses are more than 264 ( N=264 ) as multiple replies were recorded.
Based on the above mentioned utilizations of the forest resources, perturbation factors were investigated along the lift gradients. Consequences showed that among the perturbation governments, grazing/trampling accounted for highest frequence registered from trying secret plans followed by tree fell and leaf litter aggregation and others ( Fig. 1.4 ) . The maximal graze incidences were recorded at Korphu-Trong site. Some plots we come across had groundss of Tseri farming. This was confirmed with the aid of local ushers. Livestock graze and tree fell indicates that local people are dependent on the park wood for fuel wood, edifice stuffs and farm animal raising ( see Table 1.5 ) .
Fig 1.4, Frequency of the human perturbation factors ( estimated comparative factors based on ocular observations ) across four sites in JSWNP
The perturbation index showed first extremum at 750 m a.s.l. This is due to most of the colonies are located at lower height within the vales of JSWNP and they use the nearby wood. Some small towns located at higher lift where the 2nd extremum occurred at 1750 m and the 3rd at 2250 m ( Fig. 1.5 ) .
Fig 1.5 The relationship between the perturbation index and the lift gradient.
Differences in forest secret plans status ( & gt ; 10 centimeter DBH ) with perturbation strength
The 92 stock list secret plans for tree species were laid down across the four sites in JSWNP and the figure of roots, mean DBH and the denseness of trees per hour angle were assessed. Based on the above recorded perturbation regimes the forest secret plans inventoried were classified, based on the ocular observations, as really low disturbed or no disturbed, low disturbed, moderate disturbed and extremely disturbed forest secret plans. Mann Whitney brace wise trials showed that there was a important difference ( p & lt ; 0.05 ) in the average DBH between the extremely disturbed secret plans and the other of low, Moderate or not disturbed secret plans ( Table 1.6 ) .
Table 1.6, Comparison of forest diverseness and construction in different strength of perturbation
Trees & gt ; 10 centimeter DBH
No of roots
Discussion and Decision
Among the four sites in JSWNP, Korphu – Trong site showed the highest average dbh while that of Dovan – Jigmechhoeling exhibited highest figure of species ha-1 and Ada- Pataley site exhibited the highest root denseness ha-1. Most of the mountain inclines and vales along the Ada – Paraley site are directed towards south and most of the inclines receive comparatively higher rate of radiation. This consequence is supported by the fact that the structural features of species at Ada – Pataley site showed higher root denseness with shorter tallness and this could be likely the dirts are dry comparative to other sites. Korphu – Trong site showed largest figure of trees ( 76 % ) with the height scope of 20 m and more. Korphu – Trong site is represented by moist dirt and with most of the inclines are directed towards the nor’-east, North and Northwest and comparatively soil wet content is higher than the Ada-Pataley site. However, Dovan -Jigmechhoeling showed higher diverseness compared to the other three sites. Researchers ( Bratton, 1976 ; Yadav and Gupta, 2006 ) reported the micro site heterogeneousness like dirt wet and dirt alimentary concentration due to landscape heterogeneousness that affects species distributions. The consequence of incline is reported by Yadav and Gupta ( 2006 ) , in the Sariska Tiger Project, India where the forest floor is found to be different on incline confronting different waies. The inclines confronting west were somewhat xeric status and represented maximal woody species. Similarly most of the east facing inclines in JSWNP are by and large drier and represented by Pinus rocburghii and Woodfordia fruticosa where as vales were normally dominated by Ostodes paniculata, Duabanga grandiflora and Alnus nepalensis in the lower heights.
In footings of overall ecological laterality with across sites the high importance value species are different, although, the altitudinal fluctuation is about similar on all sites. The secret plan waies and secret plan places across site might hold affected the species laterality and codo-minance. The findings of Pinus roxburghii as the dominant species are consistent with the findings of the Wangda and Ohsawa ( 2006 ) in their surveies in dry vales inclines of the Bhutan Himalaya. Pinus roxburghii could happen every bit low as 500 m to 2500 m lift in the interior Himalayas. The difference in of import species across site showed similarity with the surveies by Reddy et al. , ( 2008 ) in Andhra Pradesh, India and Zhu et al. , ( 2007 ) from the secondary woods in montane part of northeasterly China.
Over all analysis of the species distributions in JSWNP showed that Castanopsis hystrix, the most dominant species followed by Pinus roxburghii, Duanbanga gramdiflora, Pinus wallichii, and Ostodes paniculata severally. Relatively cooler environment with most of the inclines being north confronting along the Korphu – Trong and Dovan – Jigmechhoeling provided contributing environment for the cool wide leaved forest species like Castanopsis hystrix. Therefore the most frequent happening as recorded was Castanopsis hystrix ( 22 % ) . However, frequent vales and complex land signifiers have created micro-environment leting the species of lower lifts to happen even at the higher height. Ostodes paniculata ( 17 % ) , Lithocarpus elegans and Schima wallichii both accounted for 16 % in their distributions.
Environmental variables showed important effects to corner species distributions in JSWNP. A Monte Carlo substitution trial showed lift as the extremely important among all the environmental variables ( Table 1.4 ) . The species profusion is affected by lift gradient. There was an happening of higher root denseness and the higher diverseness at the in-between lifts ( Fig 1.3 and 1.6 ) . The CCA analysis showed six environmental factors that is impacting the flora distribution and the factors would be: lift & gt ; dirt deepness & gt ; Carbon content & gt ; Plot location & gt ; facet. The alteration in flora types along the altitudinal gradient, based on the CCA consequence, is much greater than other environmental factors, although the part of the other factors to the distribution in flora types is evident ( Fig. 1.2 ) . Therefore, the height could be impacting on the flora distribution at regional graduated table. The other environmental factors nevertheless tended to hold little impact on flora distribution and it could be in localised landscape graduated tables and is consistent with the determination of Kang et al. , ( 2007 ) on the Helan Mountain, China. This could be because of complex landforms and microclimate heterogeneousness as described by Ohsawa ( 1987 ) as “ Inner Himalaya ” which is described as the complex heterogenous parametric quantities where similar environment could be noted at varied lift. The spacial heterogeneousness could be due to difference in the dirt wet and foods.
The consequence of the assorted hill inclines on the species is besides different. The incline scope with 6 – 10 grades showed the maximal root denseness with 401.8 roots ha-1 and slopes with 10 – 15 grades inclines showed maximal figure of species in norm of 8 species per secret plan. Plot aspect drama of import function in determining the works distribution and composing as it is associated with the solar radiations and the wet content ( Yadav and Gupta, 2006 ) . In JSWNP root denseness South -east confronting inclines had the highest average figure of works species ( 10 ) followed by south – West ( 8 ) and so west confronting inclines. However, the west facing inclines had the highest root denseness ( 500 stems ha-1 ) followed by south – E facing inclines ( 412.5 stems ha-1 ) . The North and the south facing inclines had about the same figure of species which is consistent with the findings of Yadav and Gupta ( 2006 ) .
In JSWNP, most of the east facing inclines are dry and largely dominated by chir pine forest whereas west facing inclines are normally cooler with damp environment. In secret plan location the secret plans in the back incline recorded the higher average figure of species than others ( average figure of 7 spp ) nevertheless, secret plans located on the shoulder were recorded the highest root denseness ( 431.9 stems ha-1 ) . Therefore, the diverseness form of the works species is determined by the topography and the incline direct which is evident in JSWNP, Bhutan. The JSWNP is located in the part of interior Himalayas as classified by Ohsawa ( 1987 ) , which is characterized by the deep vale and mountains with inclines of varied grades and complex landforms. The flora distribution shows distinguishable parts of sub-tropical and temperate types and normally larger infinites of ecotone parts.
The tree diverseness showed higher extremum at the mid lifts ( Fig. 1.3 ) . The extremum for diverse species might hold occurred due to transitional zone of flora that starts altering from sub-tropical or warm temperate to chill temperate ( See Ohsawa, ( erectile dysfunction ) 1987 ) . Another possibility could be likelihood of little human perturbations along this lift scope. The tree diverseness is observed low at around 900 m a.s.l because at this lift normally covered by Chir Pine wood. Besides most of the locations around 800 m a.s.l. and 1300 m a.s.l are inhabited by human colonies where nearby woods are extremely utilised and due to this the forest have degraded and in some instances the monotypic species were observed. For case, secret plans located in sokshing country comprised chiefly of Quercus griffithii and in extensively grazed countries have non-palatable species.
JSWNP is located in the cardinal Bhutan surrounded by colonies on all sides. Most of the people are dependent on the natural resources of the park in add-on to the local people populating inside the national park. Local people are non merely depending on the wood for graze and foliage litter aggregation but besides on fuel wood and lumber. Our family study on the forest resources use by local people indicated that lumber for edifice houses is non used every bit on a regular basis as fuel wood but that better quality and more wood is required for this intent. But other utilizations such as supplication flags and edifice impermanent huts, for fencing the harvests in order to guard it from wild life depredation and to build impermanent sheds for farm animal. Therefore, significant Numberss of immature trees are felled seasonally. There were besides studies of droping excessively many trees for usage of for supplication flags and has become one of the forest related issues in Bhutan ( Kuenselonline, 2009 ) . This usage of the forest resources by local community creates perturbations to corner species diverseness and constructions. The tree diverseness is lower in the secret plans near to the colonies where it is extremely disturbed. However, the diverseness is higher in the countries with history of Tseri cultivation. The secret plans with record of Tseri cultivation showed diverse species with smaller sized roots and shorter highs. This observation agrees with the findings of Schmidt-Vogt ‘s findings where the greater species diverseness was observed in woods of northern Thailand with incidences of swidden agriculture ( 1998 ) . Other than the Tseri cultivation in JSWNP, the community uses extended forest resources ( see Table 1.5 ) . The Intermediate perturbations hypothesis of Connell ( 1978 ) suggests that the diverseness of species might be higher in the countries with little perturbations.
In instance of JSWNP with respect to diverseness, the figure of woody species at the lower lifts was found to be lower and increased to mid lifts and so once more decreased while traveling to higher lifts. When the perturbations factors were assessed, the consequence showed that most of the mid-elevations secret plans were reasonably disturbed. It is found that the sampled secret plans with low and reasonably disturbed secret plans showed higher root denseness whereas extremely disturbed secret plans showed lower root denseness. Therefore, it could be due to intercede perturbation compared to low lifts and this is in consistence with the findings of Zhao et al. , ( 2009 ) in the Baishuijiang river basin China and Yadav and Gupta ( 2006 ) at the Sariska Tiger Project in India. It could be argued that the woody species distributions in the JSWNP were the looks of perturbation – diverseness form which is called the ‘Intermediate -Disturbance Hypothesis ‘ ( Robert and Giliam, 1995 ) . In JSWNP most of the forest resources use other than nearby colonies, are used seasonally where migratory graze is usual pattern. Besides most of the forest resources use involves seasonal crops that would promote some species to set up and ease addition in figure of species in reasonably and low disturbed countries. However, in countries with high perturbation some species may merely acquire nonextant that do non digest higher perturbations. The diverseness and evenness of species showed diminishing tendencies with increased incidences of graze, as reported by Alados et al. , ( 2004 ) in the Mediterranean graze ecosystems. However, families who were on a regular basis involved in forest resources harvest mentioned that they observed addition in the land vegetation and bush species in the countries with lessening in tree species. The village population of people and farm animal could be besides associated to forest resources debasement and alteration. For case, Karanth et al. , ( 2006 ) found that larger small towns with higher figure of families and population densenesss have higher impacts on the woods. But deficiency of alternate resources aggregation country could be instead of import to reason with than merely the population densenesss.
The tree denseness, species profusion and radical country were significantly higher in the interior countries of Bardia National Park, Nepal, where the human intervention was comparatively less ( Thapa and Chapman, 2010 ) . This agrees with the consequences from JSWNP in Bhutan where the tree denseness and radical country were significantly different in disturbed secret plans and besides the trees with lower dbh were found to be subjected to higher lopping. However, reasonably disturbed and low disturbed forest trying secret plans showed more stem denseness and bigger mean dbh with lower species diverseness. The species recorded showed dominant. For case most of the disturbed secret plans in Dovan and Korphu site showed largely presence of Castanopsis hystrix which is tolerant to disturbance. The species which can digest human perturbations would go dominant where as other intolerant species will extinct in the countries with frequent perturbations ( Sagar, et al. , 2003 ; Yadav and Gupta, 2006 ; Sapkota et al. , 2009 ) . Changeless aggregation of fuel wood, cutting of trees for fence and edifice stuffs, graze, foliage litter and trample can well change species regeneration capacity ( Pandey and shukla, 1999 ; Sapkota et al. , 2009 ) and in JSWNP the average dbh and root denseness were found to be comparatively lower and significantly different in secret plans with higher strengths of perturbations, therefore, it could be argued that the human impacts with higher strength has impacted the species regeneration capacity.
The consequences of the present survey indicated that forest in JSWNP is affected by human intervention but frequent and coincident multiple impacts are responsible for differences in forest status. Environmental variables evidently have higher proportion of impacts to species profusion and denseness where different phases of works growing would hold specific environmental demands. These changing characters may besides react otherwise to human perturbations at different growing phases in works life. We concluded that the human impacts evidently affected the tree species diverseness and densenesss in JSWNP, nevertheless, direction should supervise the strength of human activities so that some direction scheme may be required to except some hurtful activities. We agree with the peak value of diverseness indices at the in-between lifts of our survey nevertheless whether it is strictly based on the Intermediate – perturbation hypothesis or the mid lift consequence. However, we recommend farther surveies to narrate the precise decoupling effects of environmental and human influence to species profusion, diverseness and structural traits on the interior Himalayas forest ecosystems.
Restrictions of this survey is that our informations represent a cross sectional survey, a snapshot of forest structural traits and distribution features. This survey merely provides the first manus basic thoughts of species features nevertheless it is hard to reason where we stand in footings of forest alteration that existed due to historical perturbation variables. Further probes on the regional forms of tree diverseness and the consequence of perturbations are extremely recommended to clear up these relationships and besides features of general community property as indexs along the perturbation gradient and constitution of perturbation threshold degree in JSWNP is extremely recommended. Precedences for preservation should non be based on the peculiar species entirely. It is peculiarly of import in the context of the turning concerns with respect to forest resources utilize by local people and the precedences to protect the species of preservation importance in the national park where the impacts of clime alteration is besides a turning concern.