Floristic diversity and vegetation analysis of the community forests of South-West Haryana, India

Haryana is a landlocked state in northwest India with a geographical area of 1.3% of the country. As the development is concerned, the state has well-developed agricultural as well as industrial sectors. However, the state has poor forest/tree cover compromising only about 3.62% of its total geographical area according to India State Forest Report, 2019. The area under forest and trees is an important indicator of its environmental condition. In the mid-1970s, worldwide research interest arose into the interrelation between people and trees which led to the establishment of the definitions of the term ‘community forestry [1,2]. Learning the significance of community forests, virtually all countries around the world are working in the field of community forestry [3].


INTRODUCTION
Haryana is a landlocked state in northwest India with a geographical area of 1.3% of the country. As the development is concerned, the state has well-developed agricultural as well as industrial sectors. However, the state has poor forest/tree cover compromising only about 3.62% of its total geographical area according to India State Forest Report, 2019. The area under forest and trees is an important indicator of its environmental condition. In the mid-1970s, worldwide research interest arose into the interrelation between people and trees which led to the establishment of the definitions of the term 'community forestry [1,2]. Learning the significance of community forests, virtually all countries around the world are working in the field of community forestry [3].
The importance of forests can be estimated by the fact that they provide half a billion with substantial livelihoods, from which millions of rural people living in poverty depend on community forests for their sustenance in this developing world. It is also found evident that community forests also provide various benefits along with plenty of livelihoods such as biodiversity conservation and carbon storage [4,5]. With contradiction to the forest products required by the ever-increasing population, the availability of forest resources is scarce. Inclusive of this, the non-sustainable means of resource extraction used by the people, due to lack of knowledge and ignorance among them causing the hazardous effects on the community forests. The species of an ecosystem are very important because their activities are essential processes that support and maintain those environments [6].
In Haryana, a small portion of land is occupied by community forests that are mainly present in the south-western region of the state. As, due to the presence of subtle soil moisture and water availability in the rest of the state, the area lately under community forests has now been converted into agricultural land. Hence, community forests are mainly confined to only a few districts in Haryana i.e., Hisar, Bhiwani, Fatehabad, Jhajjar, Sirsa, and Mahendergarh. Thus, the community forests of Haryana are very significant for study. Also, no study has been reported on these ecosystems by other workers from Hisar, Bhiwani, and Fatehabad.
Keeping this and the benefits as well as rapidly degrading conditions of community forests in mind, the present study revolves around the community forests of these three districts of Haryana. During this study, various parameters like Density, Basal area, IVI, and Diversity indices (Shannon-Weiner, Simpson, Pielou, and Margalef) were estimated to analyze the ecological conditions of the flora of selected community forests.

Study Site
The present investigation was carried out in community forest ecosystems of Daya village (Hisar), Dhangar village (Fatehabad), and Bhera village (Bhiwani) of south-west Haryana (Figure 1). These sites are located in the arid regions of Haryana and are influenced by the local steppe climate. There is a little rainfall during the year. The average temperature of Bhiwani is 25.2°C with annual precipitation of 465 mm. The average temperature of Hisar is 25.1°C with about 459 mm of precipitation falls annually. While the average temperature in Fatehabad is 24.9°C with an annual rainfall of 390 mm.
The selected community forests are natural ecosystems having significant biodiversity as well as a certain level of disturbance due to activities performed by local people like grazing of animals, tree felling for obtaining fuelwood, etc. The area occupied by the three community forests i.e., Daya village (Hisar), Dhangar village (Fatehabad), and Bhera village (Bhiwani) is 50 ha, 35 ha, and 22 ha respectively. Due to the lack of literature on the community forests of Haryana, the present study was carried out as an initiative in this direction.

Vegetation Sampling
For analyzing vegetation composition and plant diversity, the quadrat method was used in the selected community forests at the three sites, i.e., Daya village (Hisar), Bhera village (Bhiwani), and Dhanger village (Fatehabad), by sampling 10 quadrats of 20×20m, randomly placed. The trees occurring within in each quadrat were quantized. The circumference of trees was measured at 1.37 m height above the ground. The shrubs and herbs were observed within sub-quadrats of size 5×5m and 1×1m respectively placed further within 20×20m quadrats.

Analysis of Vegetation Composition
The density (D), basal area (B.A.), and important value index (IVI) of the flora of selected sites were analyzed following Phillips, 1959 [7], and Mishra 1968 [8]. The importance value index (IVI) was calculated using Curtis and McIntosh, 1951 [9]. Along with this, disturbance status was also analyzed by calculating the Frequency class distribution pattern given by Raunkiaer, 1934 [10].

Population Structure of Tree Species
The population structure of trees was determined by girth class measurement and it was done according to NRSA Manual, 2008 [11].

Analysis of Species Diversity Indices
The plant species diversity (H') was measured using the Shannon and Wiener equation [12] and concentration of dominance (Cd) was determined by Simpson's index [13]. Equitability (E) was also calculated for the given vegetation using Pielou [14]. Whereas, Species richness (d) was calculated by Margalef's index [15].

Vegetation Composition
A total of 76 plant species including trees, shrubs, climbers and herbaceous plants were recorded in the community forest of the given three sites. The number of species was greater in the community forests of Daya, Hisar (54) as compared to that of the community forests of Bhera, Bhiwani (50), and Dhanger, Fatehabad (27). A total of 7 tree species were recorded in the community forest at Daya, which was dominated by Salvadora oleoides (IVI-71.47) followed by Prosopis juliflora (IVI 43.45), Acacia leucocephala (IVI 43.40) and Acacia nilotica (IVI 40.45 In the case of ground floor vegetation, a total of 33 herb species were found in the community forest at Daya village having IVI values ranging from 0.79 to 51.39, dominated by Peristrophe bicalyculata (IVI-51.39). Whereas Dactyloctenium aegyptium was found to be dominant with an IVI value of 25.89 at Bhera among the total 29 species of herbs recorded from there. In the community forest of Dhanger village, 17 herbs were recorded of which Peristrophe bicalyculata was found to be dominant with IVI value of 143.31.
In the case of climbers Tribulus terrestris (IVI-127.48) was dominant at Daya. Cucumis melo (IVI-165.13) was dominant at Bhera and at the community forest of Dhanger, Hedera helix (IVI-173.53) was found to be dominant.
The distribution pattern of plant species was also analyzed by dividing value of abundance by frequency and calculating the ratio of the two. The maximum number of plant species were found to show a contiguous pattern of plant distribution i.e., A/F ratio>0.050. Regular distribution was found completely absent while only three plant species were found to have random distribution i.e., Acacia nilotica and Prosopis cineraria in Bhera village community forest and Salvadora oleoides and Prosopis cineraria in Dhanger village community forest (A/F ratio=0.025 to 0.050).

Species Diversity Indices
The species diversity indices i.e., H', Cd, E, and d were also calculated for the flora of given community forests. The value of H' was found to be maximum for Bhera village community forest, followed by community forests of Daya village and Dhanger village respectively. Other than this, concentration of dominance i.e., Cd was observed maximum for Dhanger village community forest, followed by Bhera village community forest and Daya village community forest respectively. The value of E was found to be greatest for Dhanger village community forest, followed by Daya village community forest and Bhera village community forest respectively. While, the value of d was found to be maximum for Daya village community forest, followed by Bhera village community forest and Dhanger village community forest respectively.

Frequency Class Distribution
When frequency class distribution of different plant species in Daya village community forest was plotted on a graph it showed that maximum percentage of the total number of species is found in the frequency class 1-20% and the minimum number of species and minimum percentage of the total number of species are found in the frequency class 61-80% (Figure 2a). In the case of Bhera village community forest, the maximum percentage of the total number of plant species is found in the frequency class 21-40% while the minimum number of plant species and minimum percentage of the total number of plant species are found in the frequency class 41-60% ( Figure 2b). While at Dhanger village community forest, the maximum percentage of the total number of plant species was obtained by frequency class 1-20%, and the minimum percentage of the number of plant species was shown by frequency class 41-60% (Figure 2c).
A certain level of disturbance was recorded in all three community forests, as the frequency distribution curve was not found to be J-shaped as suggested by Raunkiaer (1934). A J-shaped curve of frequency distribution indicates that the ecosystem is intact with no signs of disturbance which was not deliberated for the three community forests indicating ecosystem disturbance in the given community forests.

Population Structure
The population structure of tree species in different community forests was also calculated (Figures 3-5) by assigning them to the girth classes as per to NRSA manual (2008). In the present study it was found that in the community forest of Daya village, the maximum number of tree species was found in the lowest girth class i.e., 0-30cm, such as Morus alba, Prosopis juliflora and Azadirachta indica. While in Bhera forest the maximum number of tree species was found to be in the girth class of 31-60cm and 61-90cm like Morus alba, Prosopis cinereria, and Pongamia pinnata. While in Dhanger forest Acacia nilotica, Prosopis cineraria, and Salvadora oleoides were found to belong to the girth class of 61-90 and 121-150.

Pearson Correlation Analysis (PCA)
Pearson correlation was also calculated for the three community forests (Table 1). It was found that density showed a positive correlation with the A/F ratio, Simpson index (Cd) and Margalef index (d) while it was found to be negatively correlated with the basal area (BA), Shannon Weiner index (H') and Pielou index (E). Other than this, BA was found to be positively correlated with E while negatively correlated with all other parameters i.e., D, A/F ratio, IVI, H', Cd, and d. H' was found to be positively correlated with E and negatively correlated with all the other parameters i.e., D, A/F ratio, IVI, H', Cd, and d.

DISCUSSION
Phytosociological studies are crucial for understanding the studies of any ecosystem. It also helps in understanding species interactions, ecosystem processes as well as services and change exerted by the external forces like various natural and anthropogenic disturbances. Many phytosociological studies have been accomplished in the forest ecosystems of Haryana [16][17][18]. In an ecosystem, plant species assemble in a particular manner and hence can help in vegetation mapping or quantification and evaluation. Thus, information regarding the floristic composition of natural ecosystems and habitat types becomes a key component for improving the long-term management of natural resources [19][20][21]. In the present study, it was found that the community forest of Daya site, Hisar is rich in plant diversity as revealed by its vegetation analysis in comparison to the other two sites i.e., Dhanger site in Fatehabad and Bhera site in Bhiwani district. The findings of the current study are equivalent to that of different ecosystems under tropical climates [22,23]. In the study, a total of 76 plant species belonging to 37 families were recorded from all three sites (Table 2-4). Similarly, Sahu et al., 2012 [24] recorded 57 species in dry deciduous forests of Eastern Ghats. Studies from the tropical dry deciduous forest in Sagar district reported a total of 36 trees, 8 shrubs, and 34 herbs [25]. Whilst a total number of 29 tree species belonging to 17 families were recorded across six sites from the tropical dry deciduous forests of Central India [26] and 14 tree species under 10 families were reported from Amarkutir, tropical dry deciduous forest of West Bengal [27].
The basal area of a tree is the circumference occupied at breast height (cbh) and is an important attribute to quantify the  vegetation structure and site quality [28]. In the present study, the basal area of the plant species varied significantly across the three sites Daya, Bhera and Dhanger village community forest. The basal area of trees in the three sites was found to be 23.739 m 2 /ha, 23.1048m 2 /ha, and 4.357m 2 /ha respectively, suggesting that the stand structure is quite healthy in all three sites. The values obtained are nearly in conformity with studies reported from some other workers [27,29,30]. The basal area of shrubs during the present study was calculated as 4.7449 m 2 /ha, 0.3857 m 2 /ha, and 0.5094 m 2 /ha for Daya, Bhera, and Dhanger  Bhera and Dhanger site respectively. The high-value of B.A. in Daya site is due to the high density of Capparis decidua which was absent in the other two sites. The results suggest that the diversity and distribution of understorey species are scarce, thus require more attention and in need of management.
Tree density also varies from 15.0 to 462.5 in the present study (Tables 2-4). So much variation may imply that the land is not being fully utilized by the tree stand. The species diversity depends upon adaptations of species and increases with the stability of the community. The Shannon-Weiner (H') index of trees for all three sites varies from 1.23 to 1.902 which falls in the range of 0.67 to 4.05 reported in tropical forests of the Indian subcontinent [29][30][31][32][33][34]. On the other hand, the concentration of dominance (Simpson's index) in the present study is out of the reported range of 0.08-0.27 in other forests [26,30]. In the present study, Cd for tree species varies from 0.156 to 0.323 for all three sites. However, Cd for herbs was found to be much lower while higher for shrubs and climbers, as compared to tree species in all three sites. This indicates the dominance of species in shrubs and climbers while diversity among trees and herbs. The value of Pielou index, E for trees was found to range between 0.85 to 0.977 and seen to follow the trend reported during the study of other workers [18,32]. The Margalef richness index for tree species occurred in the range of 0.32 to 23.72 for other tropical forests [26,29,33] for the two sites only i.e., Daya and Dhanger villages. Bhera site exhibited much higher values of 31.43 as compared to two other sites. With these values of diversity indices, it shows how the sites have lost tree species under the influence of man-made and ecological factors. In the present study, none of the sites showed the J-shaped curve as proposed by Raunkiaer (1934). The Inversed J-shaped curve is typical of well-developed forests with a broad range of tree sizes [35]. Invariably, none of the sites had the typical J-shaped curve which may reflect various degrees of disturbance in these sites.

CONCLUSIONS
In the last two decades, the popularity of community forests has grown as reflected in the ratification of community forests related programs, policies, and laws. But, the community forests of Haryana are still lacking in gaining the attention of the state government. The present study sites were found to possess a significant amount of floristic composition and diversity in different strata. The Daya village community forest was found to be better flourished and diverse followed by Bhera and Dhanger village community forests respectively. But anthropogenic activities such as tree felling for fuelwood, grazing, encroachment, etc. create high pressure on these ecosystems leading to depletion in their state. Hence, steps should be taken in the field of community forest ecology to improve the fundamental quality of these ecosystems for their sustainability as well as their living flora and fauna. Some further studies are also warranted in this field to attain more knowledge regarding the community forestry in Haryana including level of disturbance and impact of grazing as well as spread of invasive plant species in them for the sustainability and management of these ecosystems.