Pinus Roxburghii Sarg Research Articles

Unveiling the ecological alarm: People's perception towards exploring the impact of invasive plants on biodiversity and ecosystem services in the Western Himalaya

This paper presents the insights from both an ecological and people's perception study, aimed at understanding the ecological status of selected two common Invasive Alien Plants species (IAPs), i.e., Ageratina adenophora (Sprengel) King & Robinson and Lantana camara L., and the perspectives of local communities towards their use, status, and influence on biodiversity and ecosystem services as well as controlling measures of these species. For the examination of the distribution and spread of these invasive species in the forests, a quadrat-based phytosociological assessment was conducted in the three dominant forest types [Sal (Shorea robusta Gaertn f.), Chir-pine (Pinus roxburghii Sarg.), and Banj-oak (Quercus leucotrichophora A. Camus)] of Uttarakhand State. However, to assess the perception and awareness of local communities towards these IAPs and their impacts on local biodiversity, ecosystem services, and processes, a questionnaire-based study was conducted in seven villages of the Nainital district, spanning three different vegetation zones: Sal, Chir-pine, and Banj-oak forests. Perception data were gathered from 112 households through questionnaire surveys and interviews with key informants such as teachers, elders, community leaders, and researchers. The results of the ecological assessment indicate that the mid-elevation zone, particularly the Chir-pine forest, is highly prone to species invasion. However, findings from the perception study reveal that the people are aware of these invasive species, and their negative impacts on human and animal health, native biodiversity, ecosystem services, and ecological processes. Interestingly, over the past decade, invasive alien plant species (IAPs) have interfered with forests in the study area, leading to a decline in native species. According to local perceptions, factors such as deforestation, forest fires, climate change, increased transportation, no use of species in daily life, and grazing have contributed significantly to the spread of these IAPs. However, some people use these species as fencing wood, firewood, and for composting, etc. The results of this study indicate that awareness and educational initiatives could play a crucial role in mitigating and managing invasion in the Himalayan region.

Taper functions to predict the upper stem diameter of Chir pine (Pinus roxburghii) in the mid-hills of Nepal

A function that predicts the upper stem diameters of an individual tree is helpful in better quantifying the volume and devising sustainable management of commercially and ecologically important species. This study compares three forms of the taper equation (single, variable-exponent, and segmented) using destructive sample data collected from 80 Chir pine (Pinus roxburghii Sarg.) trees across three adjacent stands in the Mid hills of Nepal. A mixed-effects modeling approach was used to evaluate the 13 different taper functions, selecting the best parameter association with the random effect to avoid overparameterization. Additionally, these models were fitted to minimize errors by modeling correlation structure with continuous autoregressive correlation structure of order 1 (corCAR1) and variance with a power variance function. All models were statistically significant at 5% level in the likelihood ratio test when compared with the models fitted without these error minimization. Furthermore, model performance (root mean square error, mean absolute error, and pseudo-R2) was evaluated using k-fold cross-validation procedure. Although all taper functions described more than 95% of the variation in upper stem diameter prediction, the single-form models of Bennett and Swindel (1972) and Amidon (1984), the variable-exponent model form of Sharma and Zhang (2004), and the segmented model form of Max and Burkhart (1976) explained more than 98% percent of the variability. Residual diagnostics indicated that Sharma and Zhang's (2004) model provided better constant and minimum errors in predicting the upper stem diameter along the 8 to 20 m stem length, whereas other models exhibited higher residual errors. Despite model's better performance, variability along the upper stem diameter prediction would affect its applicability in estimating the volume at any merchantable height of individual trees.

Toxicological assessment of invasive Ageratina adenophora on germination and growth efficiency of native tree and crop species of Kumaun Himalaya.

The present study was designed to assess the allelopathic potential of invasive weed Ageratina adenophora leaf extracts on seed germination and seedling development efficiency of native tree [viz. Quercus leucotrichophora A. Camus (Oak) and Pinus roxburghii Sarg. (Pine)] and crop [(Triticum aestivum L. (Wheat) and Lens culinaris Medik. (Lentil)] species of Kumaun Himalaya. Pot experiments were conducted in the glasshouse of the Botany Department, D.S.B. Campus, Kumaun University Nainital, following a Completely Randomized Block Design (CRBD) with three treatments (C1-25%, C2-50%, and C3-100% of aqueous leaf extract) and one control, each with five replicates. The experiment lasted one year for tree species and continued until the seed maturation phase for crop species. Parameters such as seed germination proportion, root and shoot measurements, biomass, and crop productivity traits were recorded accordingly. Our bioassay results indicated that the inhibitory effect of leaf extracts on the measured traits of the selected native species was proportional to the applied extract concentrations of A. adenophora. Overall, lentil among crops and oak among tree species exhibited more inhibition compared to wheat and pine, respectively. At the highest concentration, reductions of 44%, 34%, 36%, and 24% in biomass production capacity were recorded for wheat, lentil, pine, and oak, respectively, while wheat and lentil productivity decreased by up to 33% and 45%, respectively. These results suggest that water-soluble allelochemicals produced by A. adenophora may impede the establishment of selected crop and tree species in agroecosystems and forest ecosystems invaded by this weed species. However, further studies on the characterization of phytochemicals and their specific role in seed germination and growth are warranted. Furthermore, the allelopathic potential of A. adenophora can be explored for the preparation of biopesticides and nature-friendly option to improve soil health, crop productivity, and reduce environmental pollution and management of this invasive weed.

Climate and humans interact to shape the fire regime of a chir pine (Pinus roxburghii) forest in eastern Bhutan

BackgroundChir pine (Pinus roxburghii Sarg.) forests are distributed in the dry valleys of Bhutan Himalaya. In the past, these forests have been heavily influenced by human activities such as grazing, burning, resin tapping, and collection of non-timber forest products. Bhutan’s Forest Act of 1969, which shifted forest management from local community control to centralized governmental control, greatly restricted these activities. To understand the implications of the Forest Act on the chir pine forests, we used tree-rings and fire scars to reconstruct the fire history of a chir pine forest in eastern Bhutan. This provided an opportunity to characterize the fire regime before and after the Forest Act of 1969 was implemented and assess the scale and magnitude of changes that have occurred.ResultsWe developed a 120-year chir pine fire chronology from nine sites within a single forested landscape. Between 1900 and ~ 1970, fires were small and patchy. When fires occurred, they were limited to one to two sites within the larger study area. After 1970, there was a distinct shift in fire activity, with fires in 1985, 1989, 1996, 2000, and 2013 burning > 90% of sample plots. Fire activity was positively associated with La Niña conditions (wetter, cooler) in the preceding year. This is likely the result of increased accumulation and connectivity of fuels on the forest floor in wetter years. ConclusionsPrior to 1970, the fire regime in the studied chir pine landscape in eastern Bhutan was dominated by patchy, low-intensity fires indicating that the fire regime was fuel limited. After 1970, fires became larger and more frequent. This shift was associated with the enactment of the Bhutan Forest Act in 1969, which regulated grazing and implemented a policy of strict fire exclusion in government-reserved forests. This likely led to a large buildup of fuels, particularly after La Niña years. Historical patterns of grazing and low-intensity fires prior to the Forest Act kept fuel loads low and disconnected. The cessation of most human activities in these forests after 1969 resulted in an increase in fuel loads and connectivity within the landscape. This has greatly reshaped fire regimes in the chir pine forests of eastern Bhutan over the past half century.

Tree-ring climate response of chir-pine (Pinus roxburghii Sarg.) in the sub-tropical forest, western Nepal

Tree-ring climate response of chir-pine (Pinus roxburghii Sarg.) in the sub-tropical forest, western Nepal

Forecasting of Resin Yield and Number of Blazes of Naturally Regenerated Chir Pine (Pinus roxburghii Sargent) in Himachal Pradesh by Using Single Exponential Smoothing Method

The present investigation entitled “Forecasting of resin yield and number of blazes of naturally regenerated chir pine (Pinus roxburghii Sargent) in Himachal Pradesh by using single exponential smoothing method” was carried out during the year 2020-2022. The secondary information was collected regarding the resin yield and number of resin blazes w.e.f. 2005 to 2022 from Himachal Pradesh State Forest Department. Exponential smoothing is a particular moving average technique applied to time series data and to produce smoothed data to make forecast. In exponential smoothing, one or more smoothing parameters are to be determined explicitly and those choices determine the weights assigned to the observations. Forecasting with the help of various linear and non-linear models is on the assumption that the series is stationary. Often time series is found to be non-stationary which means they are integrated and can be made stationary by differencing the time series. To check the stationarity of the number of blazes and resin yield, Augmented Dickey Fuller test was used. The results indicated that data was not approaching stationarity even after taking third difference. So, the prerequisite condition of ARIMA model is that the data should be stationary and if the time series data does not contain trend and seasonal components, Single Exponential Smoothing model was used. The Single Exponential Smoothing model was found to be best fit for the prediction of number of blazes and resin yield as per the high value of , low value of MAPE and Normalized BIC.

Effect of forest fire on soil properties and natural regeneration in Chirpine (Pinus roxburghii) forests of Himachal Pradesh, India

Abstract. Sharma Y, Gupta T, Gupta RK, Sharma PP. 2023. Effect of forest fire on soil properties and natural regeneration in Chirpine (Pinus roxburghii) forests of Himachal Pradesh, India. Asian J For 7: 125-132. Forest fires have a significant impact on the physical environment, such as land cover, land use, forest ecosystems, and biodiversity. The present study was carried out to quantify the effect of forest fire on soil properties and natural regeneration of Chirpine (Pinus roxburghii Sargent) forests in Himachal Pradesh, India. Data collection was conducted at six different sites in three forest divisions, namely Solan Forest Division, Hamirpur Forest Division and Dehra Forest Division during the year 2020. Burnt and unburnt forests were selected at each site and were compared with each other to study the effect of fire. The results reported that electrical conductivity, pH, available nitrogen, available phosphorus, available potassium were higher in burnt forests when compared to unburnt forests of the studied sites whereas organic carbon (%) was lower in burnt forests as compared to unburnt forests. Seedling density of trees was found higher in burnt forests whereas sapling density was found higher in unburnt forests. This indicates that fire is good for regeneration but frequent fires can be detrimental for the survival of seedlings. Frequent forest fires need to be prevented and that can be done mainly by social awareness and developing strategies for use of pine needles in farming practices and commercial use in paper, pulp and wood industries.

Dynamics of Ice Nucleation along the Central Himalaya, Skardu, Pakistan

Freshwater resources are precipitation and ice nucleation, which are vulnerable in environmental density with increasing human population and anthropogenic inclined indulgence, leading to the threat of complete disappearance of ice cover. Regarding global prospects, the Himalayas have grave significance regarding ice resources, and Pakistan's dependency upon fresh water from ice covers is more than 70%. Investigation of ice nucleation in the central Himalayas and Skardu regions in Pakistan indicates that abiotic factors like pH and temperature and biotic factors like bacterial presence in sediments or soil, ice meltwater, stream water and plants play a vital role in ice nucleation. Vegetation is the best habitat for bacteria with movement of 50 to 500 culturable cells/m2/sec (Suzuki et al. 1993, Morris et al. 2004 and Goodnow et al. 1990). Application of Vali's formulation c(T)= {ln (No) – ln (No -N(T))}/A for ice nucleation per bacterial cell shows biotic factors are more significant than abiotic factors. Trees like Cedrus deodara (Roxb.ex D. Don) (common name Diar) family name is Pinaceae showed the most significant tendency among the studied variables for ice nucleation, with ln c(T)= -14.84 as compared to Pinus roxburghii Sargent (botanical name) Chir (common name) Pinaceae (family name) ln c(T) = -15.9. Ice nucleation per cell (ln c(T)) in ice meltwater, stream water and sediment were -16, -15 and -15.14, respectively. P.H.PH range was near to neutral value (7) with the highest 8.4 in deposits and the lowest 7-making range of 1.4. The lowest mean monthly temperature in January from 2000 to 2022 is -12.6 oC (2013), while the warmest mean low temperature is -6.2 oC (2022), as per PMD. These temperature ranges are ideal for heterogeneous ice nucleation, as 50% of drops were frozen in the sample taken from the plants at a temperature of -10 °C. In comparison, stream water showed 35% frozen drops in this study. The research methodology following bacterial tests (H2S and Gram tests) and evaluation of abiotic factors like pH, temperature, wind direction indicates more impactful are biotic factors and low temperature for heterogenous ice nucleation.

Anti-arthritic potential of ethyl acetate fraction of <em>Pinus roxburghii</em> Sargent stem bark in Freund's complete adjuvant induced arthritis in Wistar rats

Traditional and folk medicine regularly make use of the Pinus roxburghii Sargent (Pinaceae) plant. Unfortunately, there is a lack of data on this plant's potential anti-arthritic effects.Pinus roxburghii Sargent ethyl acetate stem bark has anti-arthritic properties in Wistar rats with arthritis produced by Freund's Complete adjuvant. As a positive control, diclofenac was administered. To define the anti-arthritic activity, the influence on pain perception parameter, haematological parameters, the effect on rheumatoid factor, CRP, and serum parameters were evaluated.In this study, the ethyl acetate fraction of Pinus roxburgii Sargent was found to significantly inhibit pain perception parameters at doses of 250 and 500 mg/kg. Serum levels of RF, NO, and CRP were significantly lower in the Pinus roxburghii Sargent group compared to the disease control group. In disease-free rats, Pinus roxburghii Sargent significantly raised RBC and lowered WBC, both of which point to a suppressive effect on inflammatory mediators. The number of inflammatory cells had decreased, as seen by histopathology. Several imaging parameters, including spur formation, joint spacing, bone erosion, etc., were significantly reduced in a radiological assessment.In this study, authors noted that Pinus roxburghii Sargent had a direct effect on slowing the progression of arthritis, reducing inflammation and synovitis, and protecting arthritic joints from cartilage and bone deterioration. Stem bark extract of Pinus roxburghii Sargent has been shown to have anti-arthritic action based on clinical, biochemical, and histological analysis. Yet more research is required to pin down the precise mechanism of action.

Analysis of chemical properties of thermally treated Pinus roxburghii Sargent wood

Effects of thermal modification were determined relative to chemical parameters of Pinus roxburghii. Thermal modification of wood was carried out at 80, 120, 160, and 200 °C for 2, 4, and 6 h. The chemical properties were different for different temperatures and different heating time. All parameters were similar except for cold water soluble extractives. Among the chemical properties studied, the maximum mean value of cold water extractives (8.20%), hot water soluble extractives (12.7%), holocellulose content (71.8%), and ash content (1.46%) were recorded at 120 °C, whereas the maximum mean values of alcohol benzene soluble extractives (13.9%) and lignin content (33.7%) were observed at 200 °C. The minimum mean value of cold water soluble extractives (5.82%), hot water soluble extractives (9.27%), holocellulose content (65.8%), and ash content (1.03%) were found to be at 200 °C, while the highest value of alcohol benzene soluble extractives 12.2% (control) and lignin content (28.0%) were found to be at 80 °C.

Ecological Wood Anatomy of Pinus roxburghii in Central Nepal

Pinus roxburghii Sarg. is a gymnosperm tree belonging to the family Pinaceae having extensive distribution in Bangladesh, Bhutan, China (Tibet), India, Nepal and Pakistan. In Nepal, it is found in subtropical region at an elevational range from 500 to 2700 m asl. The aim of the present study is to determine the ecological variation in wood characters and non-anatomical characters such as diameter at breast height (DBH), tree height and altitude. Nine wood block samples were collected from the outermost part of the trunk of three matured canopy trees at three different localities between 1100 and 1350 m above sea level from central Nepal. Correlation and regression analysis were carried out to study variation in wood anatomical characters. Multiple regression analysis was done using non-anatomical factors as independent variables and anatomical features as dependent variables. Quantitative wood characters were found to be affected by change in ecological factors but not on its qualitative wood characters. Tracheids length as well as tracheid’s pit significantly varies with altitude. A weak correlation was found between wood anatomical characters and non-anatomical parameters. Tracheids length exhibited negative correlation whereas tracheids pit exhibits positive correlation with altitude. Since tracheids are the main conducting tissues in xylem of pines, decreasing length and increasing pit size of tracheids is of ecological importance. This study will help in identifying how wood characters are adapted in response to change in ecological factors as well as help to predict ecological factor disturbances.

Influence of vegetation types on soil physical and chemical properties, microbial biomass and stoichiometry in the central Himalaya

Soil physical and chemical properties and microbial biomass dynamics are significantly related to vegetation types. However, how different vegetation types influence the soil and microbial dynamics remains poorly understood. The aim of the present study is to assess the influence of vegetation types on soil physical properties (bulk density (BD), porosity, moisture, texture, and water holding capacity), chemical properties (soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), soil pH and electrical conductivity (EC), and SOC, TN and TP stocks), microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), microbial biomass phosphorus (MBP), and stocks as well as soil and microbial biomass C: N: P stoichiometry within three soil depth (0–10 cm, 10–30 cm and 30–60 cm) in central Himalaya. Five vegetation types, namely oak (Quercus leucotrichophora A. Camus) forest, Chir-pine (Pinus roxburghii Sarg.) forest, deodar (Cedrus deodara (Roxb.) G.Don) forest, Sal (Shorea robusta (Roth) forest) and one was abandoned agricultural land was selected for the present study. Principal component analysis (PCA) and correlation analyses were performed to evaluate the relationship among physical, chemical, and microbial characteristics and stoichiometry. ANOVA revealed significant differences in soil physical and chemical properties, microbial biomass, and stoichiometry due to vegetation types (P < 0.001), soil depths (P < 0.001), and vegetation types × soil depth interaction (P < 0.001). The results showed that the SOC, TN, TP, MBC, MBN, and MBP contents decreased with soil depths. MBC, MBN, and MBP contents were significantly and positively related to SOC, TN, and TP contents. Oak and deodar forests had the highest, SOC, TN, TP, MBC, MBN, and MBP contents, compared with other vegetation types. Sal forest soil (0–10 cm) had the highest SOC: TN, and SOC: TP ratios. Different vegetation types have different soil properties and stoichiometry, implying their different soil C, N, and P stocks. Thus our findings can help in developing a promising guideline for sustainable management strategies and soil management in long run.

Allelopathy effects of invasive alien Ageratina adenophora on native shrub species of chir pine forest in the central Himalaya, India

ABSTRACT Ageratina adenophora Spreng. is one of the most troublesome invasive species that has invaded various forest ecosystems in the central Himalaya. The chir pine (Pinus roxburghii Sarg.) forests in the region facing a high risk of invasion and loss understory diversity of native species. The present study comprehends the allelopathy effect of the invasive species A. adenophora residues bioassay (extract) and soil amendment against two co-occurring native shrubs viz Berberis asiatica Roxb. Ex DC. and Rubus ellipticus Sm. in a laboratory and natural forest conditions. Results revealed that a higher concentration (4% and 8%) of A. adenophora leaf, root and shoot extract have significantly inhibited (23% to 76%) and low concentration (1%) did not inhibit the seed germination, root and shoot length of B. asiatica and R. ellipticus. Furthermore, 8% (w/w) A. adenophora residue (leaf, root and shoot) amendments with the natural soil also showed significant inhibition effects (13% to 37%) on seedling growth and biomass of both the test species. Weekly A. adenophora leaf residue amendment showed higher inhibition in shoot elongation than root and shoot amendment during the experiment period. The study demonstrated that A. adenophora extract and residue amendment have strong allelopathic effects on woody shrub species and indicating allelopathy played important role in the successful establishment and rapid spread of A. adenophora in the understory of chir pine forests.

Variations in Soil Organic Carbon Stocks under Different Land-Use Categories in Subtropical Ecosystems of Kashmir

Abstract Quantification of soil organic carbon (SOC) stocks in different land uses holds vital significance because of its implications regarding carbon sequestration as the largest terrestrial carbon pool. The current study was conducted to quantify and compare SOC stocks in forest land, agricultural land, and barren land-use categories in the subtropical ecosystems of the Himalayan foothills in Kashmir. Results showed the highest SOC value in the forest soil (75 ± 11.1 Mg C ha−1) followed by agricultural soil (58 ± 7.0 Mg C ha−1) and barren land (44 ± 6.5 Mg C ha−1). SOC stocks in different land uses showed broad variations with values as high as 106 ± 11.3 Mg C ha−1 (forest soils) and as low as 14.1 ± 7.1 Mg C ha−1 (barren land). The forest SOC values responded significantly to species composition with the highest values in Pinus roxburghii Sarg. pure stands as compared with broad leaved forests. Multivariate ordination analyses revealed that the variations in SOC stocks were significantly correlated with vegetation type, altitude, and soil bulk density. The study has identified anthropogenic disturbances as a major factor deteriorating local SOC stocks and recommends immediate soil restoration efforts to enhance the ecological significance of soils as vital regional carbon sinks.

Assessment of Biomass Storage, Net Accumulation and Carbon Sequestration in Chir-Pine (&lt;i&gt;Pinus roxburghii&lt;/i&gt; Sarg.) Dominated Community Forests of Kumaun Himalaya in relation to Climate Change

The present study deals with the vegetation analysis, biomass storage and carbon sequestration at three different aspects of Van Panchayat (Community) forest sites around Nainital district of Kumaun Himalayas. All three aspects, viz; south-east (SE), east (E) and south (S) of Van Panchayat forests are dominated by Pinus roxburghii Sarg. The density of trees across all aspects of community forests varied from 450 to 670 individuals ha -1 . The basal area values reported varied from 31.16 to 56.32 m 2 ha -1 . The species diversity across aspects ranged from 0.440 to 1.389, 1.656 to 2.319 and 1.962 to 3.152 for trees, shrubs and herbs, respectively. Total biomass storage values of trees across all aspects ranged from 155.83 to 333.77 t ha-1. Net biomass accumulation by trees was 10.53 t ha -1 yr -1 on SE aspect (Chir-Pine forest), 8.05 t ha -1 yr -1 on E aspect (Chir Pine forest) and 7.96 t ha -1 yr -1 on S aspect (Chir-Pine forest). Net annual carbon sequestration of trees varied between 3.54 and 4.36 t C ha -1 yr -1 . The density, biomass storage, net annual biomass accumulation as well as carbon sequestration values reported are higher on SE aspect. It can be predicted that South-East aspect (mixed aspect) plays a significant role in forest growth and maturity as compared to East and South (singal) aspects. In general, strong rules and regulations and effective enforcement must have minimized degradation and deforestation of forests in this Van Panchyat. This will certainly help in increasing forest cover and reducing carbon emission which will lead to minimise rise in CO 2 level of the atmosphere.

Frequent burning in chir pine forests, Uttarakhand, India

BackgroundSubtropical coniferous forests of the lesser Himalaya provide critical ecosystem services but fire regimes have received limited scientific attention. We reconstructed fire regimes using tree-ring methods in a chir pine (Pinus roxburghii Sarg.) forest of Uttarakhand, India. We cross-dated tree-ring samples with fire scars from 36 trees at three sites near rural villages between 1535 and 1848 m elevation.ResultsFires were highly frequent (mean fire intervals all <6 yr) but of low severity, so most mature trees of this thick-barked species survived numerous burns. Fire scars occurred primarily in the dormant period to the middle of early wood formation in tree-rings, consistent with fire season records. Despite the high fire frequency, fires were mostly asynchronous among the three sites, indicating a bottom-up pattern of local ignitions. We observed that resin tapping of the pines interacted with surface fire by allowing fire to burn into the wood of some tapped trees and weaken their structural integrity to the point of breakage.ConclusionsOngoing frequent surface fire regimes linked to human land use are prominent disturbance factors in chir pine forests. Given that these forests support substantial human populations and form part of the watershed for many more people, the effects of anthropogenic fire and interactions with resin-tapping merit further investigation at landscape to regional scales. We suggest developing a research network in Himalayan forests as well as more broadly across southeast Asian pine forests to track interacting disturbances and their ecological and social implications.

Functional traits, growth patterns, and litter dynamics of invasive alien and co-occurring native shrub species of chir pine forest in the central Himalaya, India

Across the continents, plant invasion is identified as one of the main threats to ecosystem functioning and stability. The main objective of this research was to evaluate the differences in the functional traits between invasive alien (Ageratina adenophora (Spreng.) and Lantana camara L.) and native (Berberis asiatica Roxb. Ex DC., Pyracantha crenulata (D. Don.) M. Roemer and Rubus ellipticus Sm.) shrub species of chir pine (Pinus roxburghii Sarg.) forest in the central Himalaya. Three 0.5 hectare chir pine forest stands were selected and individuals of similar diameter were tagged for comparative studies of leaf traits, growth pattern, and biomass accumulation in structural organs of each invasive alien and native species. Our one-way ANOVA and Tukey’s post hoc test results showed that both the invasive alien species have significantly (p < 0.05) higher SLA, LWC, total chlorophyll content, foliar nutrient (N and P), RGR, LMR, SMR, nutrient uptake, and nutrient use efficiencies than native species. Leaf litter decomposition rate and nutrient release were also significantly (p < 0.05) higher in both the invasive alien species. Native species, R. ellipticus, shared some of the traits, such as leaf area, chlorophyll content, RGR, LAR, LMR, and nutrient uptake efficiency with invasive alien species. The majority of traits differed among invasive alien and native species, implying that the success of invasive alien species is best described by being functionally distinct from native species. These findings indicate that invasive alien species had advanced functional traits which may be playing an important role in a rapid spread in the central Himalaya.

New Approach for Using of Mentha longifolia L. and Citrus reticulata L. Essential Oils as Wood-Biofungicides: GC-MS, SEM, and MNDO Quantum Chemical Studies.

Background: Fungi growing on wood cause deterioration of stored food materials or discoloration of the wood itself, and the search for new and safe bioagents is recently needed. Methods: Essential oils (EOs) from aerial parts from Mentha longifolia L. and Citrus reticulata L., analyzed by gas chromatography-mass spectrometry (GC-MS), were tested for their antifungal activity by the vapor method against four common fungi, Aspergillus flavus, A. niger, A. fumigatus, and Fusarium culmorum, and confirmed by SEM examination as the oils applied on wood samples. Results: The most abundant compounds identified in the EO from M. longifolia were menthone and eucalyptol; in C. reticulata EO, they were β-caryophyllene, β-caryophyllene oxide, and β-elemene. EOs from M. longifolia and C. reticulata, at 500 and 250 µL/mL, showed potent antifungal activity against A. flavus and A. fumigatus, with 100% fungal mycelial inhibition growth (FMIG). C. reticulata and M. longifolia EOs, at 125 µL/mL, observed FMIG values of 98% and 95%, respectively, against A. fumigatus. M. longifolia EO, at 500 and 250 µL/mL, showed potent activity against A. niger, with 100% FMIG. F. culmorum completely inhibited (100% FMIG) EOs from M. longifolia and C. reticulata applied at 500 µL/mL. Pinus roxburghii Sarg. Wood, treated with M. longifolia at 125 µL/mL, showed inhibition zone values of 7.33 and 21.33 mm against A. flavus and A. niger, respectively. Conclusions: Both oils possessed good wood-biofungicide activity with the vapor method, as clearly shown by the SEM examination. These activities suggest their possible use as natural wood preservatives.

An ecological appraisal of Pinus roxburghii Sarg. (Chir pine) and Shorea robusta Gaertn. (Sal) plantations in Doon valley

The present study focused on phyto-sociological and physico-chemical attributes of soil in Pinus roxburghii (Chir pine) and Shorea robusta (Sal) plantations in a reserved estate of New Forest, Dehradun. A total of 33 plant species comprising of 18 trees, 10 shrubs and five herbs were recorded from the study area. The tree density, in chir pine was lower 950 individuals/ ha as compared to 1073 individuals/ ha in sal vegetation. In saplings, high density was observed for Syzygium cumini (20 individuals/ 100m2) in sal followed by Broussonetia papyrifera (19 individuals/100m2) in chir pine plantation. Lantana camara, marked its presence with highest density (49 individuals/100 m2) in chir pine followed by Clerodendrum infortunatum (18 individuals/100 m2) in sal plantation. Higher tree basal cover (51 m2/ha) was recorded in sal than chir pine (19 m2/ha). Similarly, the tree diversity in sal was recorded higher (1.68) as compared to chir pine (1.51) plantation. Contrarily, sapling diversity was higher (2.81) in chir pine as compared to sal (2.52) plantation. Herbaceous flora was completely absent in sal plantation. Analysis of size class distribution revealed that sal trees (~ 29%) attained 21-30 cm diameter whereas chir pine trees (68%) were under 11-20 cm diameter class mainly due to preferred growing zone of the species and habitat suitability. The soil under chir pine was slightly acidic (5.98) with sandy loam texture. Soil was comparatively good with higher soil organic carbon (2.71%) under sal plantation mainly due to high humus deposition. It is suggested to restrict wide spread of Lantana camara in chir pine plantation for the better growth of the species and enhance nutrient availability.

Water Relations of Two Adjacently Growing Tree Species Shorea Robusta Gaertn-and Pinus Roxburbhii Sarg-in the Lower Himalayan Region

Water potential (predawn and mid day), water potential components (osmotic potential at full and zero turgor, relative water content), soil water potential and leaf conductance were measured for two adjacently growing tree species Shorea robusta Gaertn and Pinus roxburghii Sarg. at an elevation of 1370m. The stands were open and the density of S. robusta was 212 trees/ha and of P. roxburghii was 141trees/ha. Presence of high number of saplings indicates both the species were regenerating well in the site despite human disturbance. S. robusta maintained relatively high predawn water potential even in summers (above -0.50MPa) and P. roxburghii showed low predawn water potential in early summer and summer season (above-1.4 MPa). P. roxburghii maintained a relatively small daily change in water potential during early summer and summer season (0.33MPa and 0.27MPa) indicating greater ability of the species to close its stomata as drought intensifies. The values of osmotic potential at full and zero turgor remained more or less constant for S. robusta from monsoon to winter and then declined during early summer. P. roxburghii showed a gradual decline in osmotic potential values from monsoon to winter season. Chir-pine has the ability of invade and grow on sites that are water stressed which can be related to its capacity to show high osmotic adjustment.. The most negative values of soil water potential were in early summer in both years. The morning and afternoon conductance was lowest during early summer and highest in autumn season.