Phytosociological Attributes Research Articles

Detailed biogeographical mapping as a useful novel tool for the conservation of endemic taxa: a case of study for Iberian orchids

Background Iberian orchids occur in plant communities designated as habitats of interest in the European Union, particularly in Mediterranean forests. Their ecological importance highlights the need for a deeper understanding of their distribution and ecological requirements in order to develop effective conservation and management policies. Methods This study focuses on the biogeographical mapping and characterisation of five Iberian and Balearic endemic orchid species at district level. Distribution data were collected from existing biodiversity databases and integrated into a Geographic Information System (GIS). In order to assign the correct biogeographical epithet to each taxon, a set of rules and criteria was developed to ensure an objective, simple and universal classification based on the species' distribution areas. Results For each orchid species, the study identified its phytosociological assignment, bioclimatic range and current conservation status. Detailed maps were produced, providing insights into the biogeographical, bioclimatic and phytosociological attributes of these taxa. Conclusions The biogeographical mapping and ecological classification presented in this study provide a basis for effective decision-making regarding the conservation and management of these orchid species. In addition, the results can be used to update their conservation status to better reflect their ecological needs and threats.

Phytosociological study of a Grassland community of Baripada, Mayurbhanj district of Odisha, India: Conservation strategies for floristic diversity

A phytosociological study of the grassland community at Maharaja Purna Chandra Autonomous College (21 º 93’ N; 86 º 76' E) was conducted from July 2022 to July 2023. The study aimed to understand the floristic diversity and propose conservation strategies. A rigorous data collection methodology was implemented using 1 m × 1 m quadrat sampling, and the findings were analyzed and presented using a novel approach. Parameters such as occurrence (+) and non-occurrence (-) of species, frequency, density, abundance, basal area, basal cover, and Important Value Index (IVI) were recorded for 36 species (18 grasses and 18 non-grasses) throughout the research period. The study revealed that certain species, including Chrysopogon acciculatus and Evolvulus nummularius, exhibited high frequency, density, abundance and IVI throughout the research period. Conversely, Eragrostis unioloides and Sida cordifolia showed the lowest IVI during the study. Basal area and basal cover data indicated an inverse relationship between grasses and non-grasses. The total Relative Frequency (RF), Relative Density (RD), and Relative Dominance (RDo.) of the community were consistently around 100 for each month, and the total IVI values were approximately 300 each month. These results underscore the need for effective conservation strategies to preserve the unique floristic diversity of this grassland community. The remarkable phytosociological attributes of this experimental grassland community may be attributed to the topography, soil composition, and climatic conditions of the locality.

Environmental factors determining weed species distribution in organic manure and inorganic fertiliser smallholder maize (Zea mays L.) production

AbstractWeeds are a major concern in crop production, and their environmental plasticity hinders successful control. A phytosociological study assessed weed distribution patterns in smallholder maize (Zea mays L.) production under different climatic and soil factors in the 2020/2021 and 2021/2022 cropping seasons. Thirty‐six maize fields from the Highveld (Mankayane) and the Middleveld (Luve) of Eswatini, were investigated with three fertiliser regimes applied (cattle manure only, cattle manure plus inorganic fertiliser and inorganic fertiliser only). Phytosociological attributes of weed species including density were collected using a 25 m transect placed horizontally at the centre of each field. Climatic factors and soil physiochemical properties considered included altitude, rainfall, temperature, soil texture, soil pH, nitrogen, phosphorus, potassium, calcium, magnesium, copper, iron, zinc and manganese. Fifty‐six weed species belonging to 16 families were recorded. Distance‐based multivariate multiple regression (DistLM) analysis was used to determine the relationship between weed species composition as the dependent variable from the fertiliser regimes and the environmental factors as the independent variable. Eight environmental variables explained 25% variation in species distribution namely; altitude, temperature, nitrogen, phosphorus, potassium, copper, magnesium and percentage silt. At Luve, temperature, copper and magnesium significantly explained weed distribution in all three fertiliser regimes, while phosphorus influenced weed distribution in the manure only regime. At Mankayane, nitrogen affected weed distribution in the manure plus inorganic fertiliser and inorganic fertiliser regimes whereas altitude, phosphorus, potassium, and %silt influenced weed distribution in the manure only and manure plus inorganic fertiliser regimes. The observations suggest that some weed species coexist between fertiliser regimes and study areas while others occur in specific environments only.

Phytosociological Studies of the Flora of Dhanamanjuri University Campus in Imphal West District (Manipur), India

Aims: To study the life forms and biological spectrum of the vegetation of Dhanamanjuri University Campus, Manipur to determine its phytoclimate and species diversity. Study Design: The vegetation of the whole university campus was studied and the site selection was made randomly. Place and Duration of Study: Dhanamanjuri University Campus is located at the intersection of 24.82ºN Latitude and 93.94ºE Longitude. The study was carried out from March to September, 2023. Methodology: Life forms were determined in the study area after detailed floristic studies. Vegetation classification on a physiognomic basis as per Raunkiaer’s system as modified by Ellenberg and Mueller-Dombois. Frequency, density, abundance and basal area were calculated for quantitative analysis. Both Shannon- Weiner Index and Simpson index were calculated for diversity studies. The degree of association between two randomly selected species was studied with a simple index of association IASM. Results: The biological spectrum of Dhanamanjuri University Campus consists of 183 plant species belonging to 163 genera distributed over 74 families. Due to predominance of Phanerophytes (54.1%) and Therophytes (22.4 %) over the other life-forms, the study site was assigned to the “Phanero-Therophytic” Phytoclimate. The values of the Shannon- Weiner Index and Simpson Index were found to be 1.5202 and 3.101 respectively. For the degree of association between two randomly selected species χ2 value was calculated to be 0.101 inferring that the two species are not associated with each other, rather they are independently distributed in the site. Conclusion: The current study has described the vegetation of the Dhanamanjuri University Campus, as per Raunkiaer’s terminology as “Phanero-Therophytic” phytoclimate. The study also shed light on various phytosociological attributes of plants growing on the campus, thus shedding more light on the diversity and distribution patterns of the plants growing there.

Effect of invasive species on forest composition in tropical dry forest: a case study of invasion by Gliricidia sepium

Ecological concerns caused by biological invasion have been considered an inevitable threat to global sustainability. The superior competitive ability of invasive plant species (IPS) has an impact on vegetation composition and loss of native flora. Recognising IPS at an early stage would significantly contribute to controlling invasive plants, protecting biodiversity and formulating appropriate strategies. Most of the studies available on invasive plants are descriptive and largely confined to non-woody species. The present study focused on the alien Gliricidia sepium, a tree species, to determine the invasive potential of its distribution in tropical dry deciduous forests of Central India. Forty square plots (25 × 25 m) were laid out at each uninvaded and invaded forest to enumerate phytosociological attributes to determine the impact of G. sepium on vegetation composition and community structure. Higher density (37.2 individuals ha−1), basal area (6.32 m2 ha−1) and importance value index (95.8) contributed by G. sepium clearly showed the suppression of seedlings, saplings and trees of native forest species at the invaded sites in terms of species richness, cover and other attributes as compared to at the uninvaded sites. Further, other invasive attributes such as higher seed production, dieback phenomenon, higher coppicing power and higher growth rate as observed during the study clearly affirmed the early speculation that the species might be invasive. The species has a strong potential to spread vigorously and may gradually become invasive throughout the country as already reported from various parts of India. In the present study area, G. sepium was introduced due to restoration and plantation programmes and our findings indicate its negative impact on the native vegetation. Thus, we strongly recommend the avoidance of this species for both plantation and restoration programmes, especially for Indian forests. The study helps in early recognition and rapid monitoring of G. sepium to control its spread throughout the country.

Soil nutrients determine leaf traits and above-ground biomass in the tropical cloud forest of Hainan Island

Identifying soil characteristics associated with the plant’s resource use and acquisition strategy at different scales could be a crucial step to understanding community assembly and plant strategy. There is an increasing trend that plant functional properties can be an important driver of ecosystem functioning. However, major knowledge gaps exist about how soil abiotic properties, shape species diversity, above-ground biomass (AGB) and plant functional diversity in the Bawangling tropical forest (TCF) of Hainan island. Hence we hypothesized that plant functional traits and above-ground biomass would be strongly associated with soil abiotic factors given their direct relationship to soil resource acquisition and use. Here, we used 12 plant functional traits (FTs), above-ground biomass (AGB), and five soil nutrients in the Bawangling tropical cloud forest of Hainan Island by using a polynomial regression model and multivariate correlations to show relationship and identify how plants allocate their limited resources to adapt to their surroundings. Various phytosociological attributes were assessed and an Importance Value Index (IVI) value was calculated for each species to determine the dominant species. More than half of the total variations could be attributed to interspecific variations in H, DBH, LA, LMA, and LDW. From a taxonomic perspective; we found that species-level variance was more significant for plant functional traits and soil nutrients like TN, AP, TP, and OM. On the other hand, variation in specific stem density (SSD), leaf thickness (LT), leaf phosphorus (LP) and leaf soluble sugar (LS) was an exception for these tendencies. Among soil nutrients, soil nitrogen and phosphorus significantly impact the species and functional traits. Furthermore, the soil AN and TP we also found to have a comparatively strong positive relationship with above-ground biomass (AGB) as compared with other soil nutrients. The morpho-physiological functional traits showed a trade-off between conservative and acquisitive resource usage. These variations suggested that the relationships of functional traits, AGB, and species with soil nutrients mainly AN and TP in tropical cloud forests can directly affect the growth, reproduction, and survival of the species and are beneficial for the species co-existence and maintenance of biodiversity.

Effects of land use types and environmental factors on woody species diversity in agricultural landscapes of Jimma Ganati District, Western Oromia, Ethiopia

Nowadays agricultural expansion and the concurrent climate variability jointly jeopardized global biodiversity in general and plant species diversity in particular. Assessing current diversity status of different land uses is a proxy for anticipating their individualistic resilience against future climatic variability. Here we explored woody species composition, diversity, distribution, and indicator species across five agricultural land uses. For this we employed a systematic sampling design to collect phytosociological attributes of woody plant species from 103 plots in four landscapes at a regular distance following transect lines. For comparative diversity analysis, we used linear mixed effects model using the lmer function and subsequently, post hoc pairwise comparisons with the emmeans function of R software. To visualize species composition dissimilarities between the land uses, we applied NMDS ordination based on Bray-Curtis dissimilarity index and subsequently, adonis2 () function (R software) was used for testing its significance and pair-wise PERMANOVA analysis. Linear regression model and multiple regression model by Envfit function was used to test the effect of environmental topographic variables on the species distribution. The result indicated that, 104 woody plant species belonging to 52 families were collected, in which significant differences in species richness and composition among the five land use types were showed. The result reveal that, forest is with the most diversified species assemblage followed by home gardens. However, grazing land is the least in species diversity. Among topographic variables, elevation gradient shows significant influence on diversity and species compositional dissimilarity among the five agricultural land uses in which 38 species were significantly contributed to the dissimilarity of species composition. Species richness and woody stem abundance declines with increasing elevation. However, slope and aspect does not show significant effect on these attributes analysis. Indicator species assessment (IndVal.) showed that, 20 species were significantly (P ≤ 0.001) associated with at least one of the five land use classes in agricultural landscape. In sum, this study highlights that, changes in woody species diversity, composition and spatial patterns are the responses to types of land uses of varying disturbance intensities and topographic elevation as a proxy to different environmental factors.

Population Structure and Regeneration Dynamics of Tree Species in Banj Oak Forests of Tehri Garhwal, Western Himalaya

Forest regeneration is a natural process of forest resource reclamation through production of young ones (saplings and seedlings). Tree species show variable regeneration potential in different associations and response to natural and man-made factors. Banj oak (Quercus leucotrichophora A. Camus), one of the important forest forming tree species in western montane Himalaya, is facing regeneration failure in different locations. The present study attempted to assess the population structure and regeneration of Q. leucotrichophora and associated tree species in five different stands (sites) of a less explored region (Tehri Garhwal, Uttarakhand, Western Himalaya). To investigate the phytosociological attributes, ten sampling quadrats (400 m2) were laid in random sampling manner in each forest stand for surveying tree layer, 2 sub-quadrats (25 m2) for saplings, and 5 sub-quadrats (1 m2) for seedlings in each sampling quadrat. Among the studied forest stands, tree species richness ranged 8 to 11 (8.8±1.3), total stem density (ind/ha) 750 to 950 (846±85.6), and total basal area (m2/ha) 18.68 to 29.18 (24.1±3.9). Based on abundance data the banj oak showed ‘good’ regeneration statuses (density of seedling > saplings > adult trees) in all forests. The distribution of adult tree individuals into different size classes (DBH classes) also indicate ‘good’ regeneration pattern (higher density in lower size classes and gradual decrease in density towards higher classes or forming a reverse J-shaped pattern). However, majority of the banj oak associated species (e.g. Prunus cerasoides, Pyrus pashia, Rhododendron arboreum, etc.) represented ‘fair’ regeneration statuses (seedlings > or ≤ saplings ≤ adult trees). Overall, the results of this study shed light on the positive prospects for Q. leucotrichophora regeneration and the importance of sustainable coexistence between human communities and these vital forest ecosystems.

Understory diversity and forest soil properties in different forest stands in Northern Chhattisgarh, India

The present study deals with the understory structure, diversity, and soil macro and micronutrients in various forest stands of the Duldula forest in northern Chhattisgarh. Forest stands include four natural (dense, moderately dense, regenerated, and degraded forests) and one plantation (teak). Stratified random sampling methods were used to evaluate the phytosociological attributes of shrubs, climbers, and herbs in various forest stands. Soil samples were analyzed for macro and micronutrients at two different depths (0–10 cm and 10–20 cm). A total of 14 shrubs, 17 climbers, and 30 herb species representing 9, 8, and 12 families, respectively were recorded from various forest stands. The total density value of shrubs, climbers, and herbs ranged between 600 and 1760 individuals ha−1, 320–5240 individuals ha−1, and 356,000–684,000 individuals ha−1, respectively for different forest stands. Shannon index values for shrub, climber, and herb ranged between 0.78–2.88, 1.68–2.45, and 2.57–3.59, respectively. The soil of the study area was found to be acidic in nature with moderate levels of organic carbon (%), macro, and micronutrient status. Considering the total density value of various forests stands highest number of shrubs, climbers, and herbs were recorded in degraded forests which indicates the process of degradation facilitates the growth of understory vegetation in comparison to tree species. In most cases, the soil attributes were higher in dense forests. This, therefore, indicates that sustainable management of the soil is essential for the restoration of degraded forests to a natural condition.

Species Diversity, Phytosociological Attributes and Regeneration Status of Pench Tiger Reserve, Maharashtra, India

Aims: Pench Tiger Reserve (PTR) is known for its rich biodiversity comprising of tropical deciduous forests as their primary forest type. Tropical deciduous forests are enriched with economically important species. They serve as habitat areas for most of the wild animals for their food and shelter. So, a phytosociological investigation was carried out in PTR to know the information on plant cover dynamics related to human activity, climate change, and all other factors affecting plant development.
 Place and Duration of Study: Pench Tiger Reserve (PTR), June 2021 to December 2022.
 Methodology: The study was carried out by laying out 47 sample plots in the PTR by dividing Tiger Reserve into 7 ranges. The plot size was 0.1 ha with 31.62 m x 31.62 m quadrats. Varied diversity indices such as Simpson, Shannon–Weiner, species evenness, and IVI were calculated according to standard formulae. Carbon stock, vegetation analysis and IVI value of each species were calculated and analysed.
 Results: A total of 102 species, comprising 90 genera and 44 families, were reported. The dominant family in the study area was Leguminosae, followed by Malvaceae and Poaceae. The Shannon–Weiner index was 2.92 and the Simpson index was 0.103, indicating moderate diversity with less dominance of trees, saplings, and herb layer in the area. Top five species holding highest IVI value are Tectona grandis (66.20), Lagerstroemia parviflora (20.44), Chloroxylon swietenia (19.91), Lannea coromandelica (18.35), and Terminalia tomentosa (16.62).
 Conclusions: As a part of long–term monitoring programme for the tree communities in the Pench Tiger Reserve, the current study has generated baseline data that will be used to evaluate the current ecological effects of ongoing and future climate change.

Study of Plant Diversity in Red Sanders Park in Chittoor District of Andhra Pradesh, India

The study deals with the assessment of plant diversity in Red Sanders park in Chittoor district of Andhra Pradesh, India. A total of nine species of trees belonging to six families with 1625 individuals, 25 species of shrubs belonging to 18 families with 2,042 individuals and 40 species of grasses and herbs belonging to 14 families with a total of 1,016 individuals were encountered. Quadrat size of 400 m2 were established for trees, 100 m2 for shrubs, 20 m2 for grasses and herbs. In terms of IVI, Pterocarpus santalinus was found to be the most dominant tree species, chromolaena odorata was found to be the most dominant shrub species and Bothriochloa ischaemumwas found to be the most dominant grasses and herb species. The result of the phytosociological aspects in all four sites concluded that for trees, Site-IV showed the highest value for Shannon-Weiner Diversity Index (H) (1.73). For shrubs, Site-I showed the highest value for Shannon-Weiner Diversity Index (H’) (2.52). For grasses and herb, Site-III had a Shannon-Weiner Diversity Index (Hˈ) of 2.62. The quantitative analysis of diversity and phytosociological attributes of tree species recorded from the present study may provide baseline information for formulating a working plan for conservation and management strategies for the forest.

PAT: Phytosociology Analysis Tool

Researchers quantify vegetation characteristics using phytosociology studies. The data collected from vegetation surveys, such as tree girth and height measurements, are used to calculate various phytosociological attributes like frequency, density, basal cover, important value index, etc. In general, they are calculated using an Excel spreadsheet and a lengthy mathematical process. There are a few open-source or free software available to compute some of these parameters. However, they are not user friendly for most researchers. Also, these software primarily doesn’t compute basic phytosociological attributes. In view of these constraints and to ease researchers work, we have developed a simple tool, “PAT” Phytosociology Analysis Tool,” that computes the maximum attributes from the field collected vegetation data. The PAT GUI is simple. PAT computes results using standard formulas after users upload a csv file in the required format. Users can download the table's results and figures in PNG format.

Distribution Pattern and Management Strategy of Invasive Weed Parthenium hysterophorus L. in Gorakhpur, India

Background: Parthenium hysterophorus L. (Family Asteraceae, local name Chatakchandni), an invader weed, assumes importance and poses a problem because of its nuisance value. The present study accounts for its population structure, community relation and its probable association with neighbour species within the major grassland vegetation types of the region. Materials and Methods: For the study of population status, phytosociological characters, neighbour relations of Parthenium and its contribution to the two major grasslands’ the managed and natural were calculated by the standard sampling methods. Results: Highly disturbed or completely cleaned sites may be fast colonized and aggregated by Parthenium, as evident from the values of its phytosociological attributes. In natural grassland, however, the number of species as the nearest neighbour of Parthenium was quite high. Parthenium was found to occur at all different stages of growth and at every stage of its life cycle throughout the year. In the months of July, November and March, a much greater number of individuals were in the seedling stage. Conclusion: Since there is no lapse period between seed dispersal and germination, effective management may be exercised only before they enter the reproductive phase. Since there is no mode of asexual regeneration in this species, manual elimination must be held at juvenile stage to get an area rid of this noxious weed.

Effect of polyethylene sheet colour and in situ solarization durations on the phytosociological structures of the predominant weeds in humid environment of southern Nigeria.

High humidity favours the proliferation of a wide range of weed species. Studying the phytosociological attributes of weeds in a humid area provides insight into the dynamism and relative importance of each weed species peculiar to the area which is very important in understanding crop-weed interrelationships and highlights the bases for effective management stratages. An experiment was conducted in 2019 and 2020 cropping seasons at the Department of Crop Science Teaching and Research Farm, University of Calabar, to identify the predominant weeds in the farm area and assess their responses to polyethylene colour and soil solarization duration. The experiment was a factorial combination of two polyethylene colour (black and transparent) and five in situ soil solarization durations (0, 8, 12, 16 and 48 weeks), laid out in randomized complete block design (RCBD) with three replications. Data were collected on the phytosociological characteristics of the weeds on four weekly intervals up to the twentieth week. The predominant weeds identified in the experimental area were Eragrostis ciliaris L., Cynodoon dactylon L., Panicum maximum Jacq., Axonopus compressus Beav., Kyllinga bulbosa Beav. and Kyllinga erecta Schum., Gloriosa superba L., Ipomoea involuncrata P., Calapogonium mucunoides Desv., Aspillia bussei O. Hoff, Ageratum conyzoides L., Phyllantus amarus Schum., Caldum bicolor Vent., Triumfeta rhomboidea Jacq., Cleome rutidosperma DC., Euphorbia heterophylla L., Mitracarpos villosus DC., Oldenladia. herbacea L. The relative density of Caladum bicolor was higher across the treatment in both years, reaching up to 37.7 % in the plot solarized for 16 weeks using black polyethylene, followed by P. maximum with upto 18.40 % in 2019 and Gloriosa superba (20.50 %) in 2020. The highest Important Value Index was recorded by Caladum bicolor reaching up to 28.7 % in the plot solarized for 16 weeks using black polyethylene. The lowest species variation was recorded in the plots solarized for 16 to 48 weeks irrespective of the polyethylene colour. In situ solarization of up to sixteen weeks using black polyethylene effectively controlled majority of the weed species in both years and is recommended for effective weed suppression in cassava farms in humid environment.

Study on the major gardenland weeds in the Vayalogam soil series of southern Tamil Nadu

Weeds are a major issue in crop production, accounting for more than 45% of yield loss. As a result, timely and appropriate weed management practices should be used to achieve good crop stand and yield. Knowledge of the major weeds is extremely helpful in selecting appropriate weed management practices. This study was conducted during 2022 at Agricultural College and Research Institute, Madurai to identify the major weed flora in the Vayalogam series of Tamil Nadu. Fifteen crops viz., maize, sorghum, pearl millet, finger millet, barnyard millet, foxtail millet, blackgram, greengram, cowpea, gingelly, groundnut, safflower, cotton, tobacco and sunnhemp were sown and various observations on the weed phytosociological attributes were recorded. The results revealed the major weed flora present and the crop which was least and highly susceptible to weed infestation. Phytosociological attributes of weeds viz., density, frequency, relative density, relative frequency, importance value index and summed dominance ratio, identified Trianthema portulacastrum as the major weed and millets and pulse crop showed greater tolerance to weeds growth due to quicker growth in the Vayalogam soil series of southern Tamil Nadu. Hence, millets and pulses can be grown in these areas with minimum weed management practices.

Elevational pattern, structure, and regeneration status of woody taxa along a semi-disturbed timberline ecotone in northwestern Himalayas

The composition, structure, and patterns of vegetation undergo a noticeable shift along the elevational gradient, and this is regulated by various abiotic variables, primarily the elevation and edaphic characteristics. The present study investigated the change in community characteristics of woody vegetation along a vertical gradient from 2800 m till 4000 m in parts of upper Bani Wildlife Sanctuary in Jammu and Kashmir. In all, 40 woody species were recorded including 11 trees and 29 shrubs with a distinctive hump shaped pattern that becomes steeper with the rising elevation. Quercus semecarpifolia Sm. and Betula utilis D.Don. exhibited a wide elevational range (3000–3500 m asl), eventually forming the climatic climax along southern and northern aspects. The diversity and phytosociological attributes peaked at intermediate elevation with H¯=1.74 recorded for trees and H¯=2.48 observed for shrubs. The average density and basal cover for trees and shrubs ranged between 75.50 Nha−1 & 20.09 m2ha−1 and 69.31 Nha−1 & 4.50 m2ha−1, respectively. The species turnover rate was recorded high in case of trees (0.11–0.77) and low for shrubs (0.17–0.29). A modest density of 114 seedlings ha−1 and 249 saplings ha−1 was recorded across the forest types. The low seedling (0.22) and sapling (0.48) per tree ratio indicated a low regeneration performance anticipating a very slow upslope movement of the tree line. This may result in population decline of a few select species in future, necessitating effective monitoring and management intervention for which these findings will be helpful.

Spatial Distribution and Invasion Potential of the Naturalized Downy Thorn Apple (Datura innoxia): Evidence from Classification and Ordination

The present study aimed to assess the spatial distribution and invasion potential of naturalized Datura innoxia Mill., a member of the family Solanaceae, across elevation, edaphic, and climatic gradients in invaded communities of semiarid regions in northern Pakistan. The species’ phytosociological attributes, diversity indices, and biotic and environmental factors were assessed in 21 sites (210 plots) and categorized into three elevation groups separated by Ward’s agglomerative cluster. The vegetation was dominated by annual species, which facilitated the naturalization and invasion of alien species. The groups were dominated by D. innoxia, having different codominant species Parthenium hysterophorus L. in Group I, Medicago denticulata in Group II, and Parthenium hysterophorus in Group III; however, the third codominant species of groups I and III were different. In addition, Canonical correspondence analysis (CCA) unveiled that abiotic factors such as elevation (r = −0.65), mean yearly temperature (r = 0.79), annual yearly humidity (r = 0.76), and day length in hours (r = 0.79) and biotic factors such as cultivated fields (r = −0.83) and traffic density (r = 0.70) were strongly correlated on canonical axes, revealing their vital importance in determining vegetation structure. The study concluded that this naturalized species propagated efficiently in the present environmental conditions and if these conditions prevailed, the species would be established as an invasive species. Therefore, control of this naturalized species is critically important, including their exploitation for medicinal and phytochemical utilization, which will enhance the protection of native populations.

Response of understorey vegetation in chir pine forests to prescribed burning in Shiwalik region of Himalaya

Aim: The present investigation was carried out to understand the impact of controlled/prescribed burning on understorey vegetation in chir pine (Pinus roxburghii) forests of Shiwalik region to manage the summer fire damage. Methodology: Chir pine forest areas of two hectares (ha) each were selected at three sites in Shiwalik region of Himalaya for prescribed burning. Each forest area was delineated into three plots of which one plot was burnt during mid-winter in the year 2017 (B1) and another plot burnt twice (B2) during 2017 and 2018 whereas the third was kept unburnt plot (C) in each site. The phytosociological attributes of understorey vegetation were studied in November, 2018. The difference in density of shrubs (plants 25 m-2) and herbs (plants m-2) in unburnt (C), once burnt (B1) and twice burnt (B2) was analyzed through critical difference (CD). Results: Total density (plants 25m-2) of shrubs ranged from 7.15 to 12.95 in unburnt (C), 3.90 to 8.40 in once burnt (B1) and 2.25 to 4.65 in twice burnt (B2) plots whereas total density (plants m-2) of herbs varied from 25.83 to 44.95 in unburnt (C), 33.20 to 75.92 in once burnt (B1) and 29.31 to 90.93 in twice burnt (B2) plots. The density of shrubs was significantly higher in unburnt plots (C) as compared to burnt plots and vice versa for herbs. The Shanonn Wiener Index (H) ranged from 1.76 to 2.39 for shrubs and 2.32 to 3.15 for herbs. Interpretation: The density of herbs was higher in burnt plots and it was vice versa for shrubs. The prescribed burning enhanced diversity of herbs while shrubs diversity decreased with burning.

Phytosociology and Diversity Assessment of tree species of Northern Delhi Ridge Forest

The interaction of biodiversity with the physical environment is the bedrock of sustainable development.The world’s forests covered more than 4 billion hectares, accounting for 31% of total land area or 0.6 ha percapita. Tropical forests in India, which are mostly deciduous, are poorly understood in terms ofphytodiversity, phytosociology, and quantification regimes. Ridge forests of Delhi are of great interest forbiodiversity management in the city. Phtyodiversity inventories set a baseline for other forest managementstudies and initiatives. The Northern Delhi Ridge also known as the Kamla Nehru Ridge the study area forthe current work, is located in Delhi, India, one of the significant biodiversity rich areas in the Delhi, tostudy the phytosociological attributes of tree species from the sampled inventory of different tree taxa. Thestudy revealed that average tree density per hectare for the Northern ridge forest as 322 trees/ha.

Assessment of composition and spatial dynamics of weed communities in agroecosystem under varying edaphic factors

Weeds are important components of the agroecosystems due to their role as primary producers within the farming systems, yet they are considered as major constraints to crop production. A phytosociological study was conducted to assess the composition and spatial distribution of existing weed species under the influence of various edaphic factors in the 15 wheat fields. Quadrat method was applied and different phytosociological attributes including abundance, density, and frequency were estimated by randomly laying down 10 square-shaped quadrats of size 1m2 in each wheat field. A total of 34 weed species belonging to 17 families and 30 genera were explored from 150 quadrats. Fabaceae and Asteraceae were ubiquitous plant families. Various edaphic factors such as; soil texture, electrical conductivity, soil pH, total dissolved solids, nitrogen, calcium carbonate, organic matter, NaCl, calcium, phosphorous, potassium, sodium, and zinc were determined. Pearson's correlation was employed to correlate weeds and the potential edaphic variables. The results depicted that most of these weed pairs' associations correlated positively. Simultaneously, the abundant weed species including Trifolium repens, Coronopus didymus, and Urtica dioica showed a positive correlation with most of the investigated ecological variables.