Investigating the floristic diversity indices of plant species in district Charsadda, Khyber Pakhtunkhwa, Pakistan

The floristic study carried out during 2017-2019 revealed that, district Charsadda comprised total of 146 plant species belonging to 58 families and 127 genera. The leading families were Asteraceae with 14 species (9.58%), Poaceae 12 species (8.21%), Solanaceae 8 species (5.47%) and Cucurbitaceae 7 species (4.79%). Apiaceae, Brassicaceae, Lamiaceae, Moraceae, Papilionaceae contribute by 5 species each (3.42%), Chenopodiaceae, Rosaceae having 4 species each (2.73%), Amaranthaceae, Euphorbiaceae, Malvaceae, Polygonaceae, Pteridaceae contributed by 3 species each (2.05%), Alliaceae, Arecaceae, Asclepiadaceae, Cyperaceae, Ebinaceae, Equisetaceae, Fabaceae, Genetaceae, Geraniaceae, Mimosaceae, Myrtaceae, Oleaceae, Pinaceae, Rhamnaceae, Rutaceae contributed by 2 species each (1.36%). The rest of the 27 families contributed by 1 species each (0.68%). The most dominant life form was therophytes having 66 species (45.20%), Microphanerophytes 22 species (15.06%), and Chaemophytes 18 species (12.32%). Hemicryptophyte 14 species (9.58%) Nanophanerophyes 10 species (6.84%), Geophytes 9 species (6.16%), Megaphanerophytes 4 species (2.75%) followed by Mesophanerophytes having 2 species (1.36%). Leaf size spectra of the flora showed that the most dominant leaf size class were microphyll having 54 species (36.98%), nanophyll 32 species (21.91%), mesophyll 29 species (19.86%), leptophylls 17 species (11.64%), megaphyll contributed by 8 species (5.47%) followed by macrophyll which represent 5 species (3.04%) and the one species is aphyllus. The dominant therophytic life form showed that the flora of the area is under severe anthropogenic activity. This study not only gives information about the flora of Charsadda but can provide a baseline for future studies and plantation of this area.


Introduction
A huge number of plant species are yet to be uncovered by the botanist. Therefore, the floristic report is the only source to get botanical information about the area and it may help in starting for detailed study [1].
The word floristic is derived from flora which means to list all types of plant species or plant taxa within specific geographical area [2]. To improve conservation stratagems for plants of any area, it is necessary to have a comprehensive floristic record of the area centred on collection and correct documentation [3]. Floristic study is a very important for ecological sustainability and conservation of plants for an area. Floristic research is one of the most effective method to manage proper and protection of plants [4]. The documentation of the local plants with the description of an area is very necessary, because it can provide informa tio n throughout the time about distributio n, occupancy, growing season and species rigidity of the available plants [5]. Floristic study also provide information about new species in a specific area, so by that way we can also analysis about migrated plants species [5]. Furthermore, the documentatio n of the plant species of the specific area is play chief role in environmental science respect to climate change [6]. Respect to climate change, Life form spectrum may also provide information about plant species, population size and their distribution over the area [7]. The life forms of plants are different in every zone on the basis of altitude. Three types of climates can be seen on earth, which includes phanerophytic in tropic, therophytic in desert and hemicryptophytic in cold temperate zone [8]. This system of grouping of life forms is broadly accepted and it's has been globally followed. The present study was started to report the floristic composition and its ecologica l characteristics of district Charsadda. District Charsadda is located in the west of Khyber Pakhtunkhwa province of Pakistan. It is bounded by district Malakand on the north, district Mardan on the east, district Peshawar on the south and district Mohmand on the west. It is situated on Latitude of 34.150N and Longitude of 71.730E (Fig. 1) [9]. The district cover an area of 996 square kilometres and it is divided into 2 tehsils and 46 Union Councils. It is situated 282 meters above sea level in elevation.
The predominant language is Pashto, spoken natively by 99.4% of the total population [10]. Temperature is variable from place to place, the coldest month of year is January, in which the average temperature is 5-10 ºC, while June is the hottest month in which the temperature raised up to 44 ºC. The average rainfall is 82 mm per year. The most precipitation fall in the month of august [11].

Figure 1. Map of district Charsadda (study area)
The main crops of the area are wheat, sugarcane, maize, tobacco, rice and several weeds [12]. Most of the area contains sandy, loamy and salty soil [13]. The

Phanerophytes
Most of the species are shrubby and tree, whose perennating buds are borne on aerial shoot reaching a height of at least 25 cm or more above the ground surface.

Data analysis
The data is analysed with Microsoft excel 2019.

Results and Discussion Floristic and ecological attributes
The flora of district Charsadda consisted of 146 plant species, which is belonging to 58 families. In this study, family Asteraceae was the dominating family having, 14 [16][17][18][19], in which the Asteraceae and Poaceae were leading families in their study work. Seasonal variation of vegetation shows that highest numbers of species i.e. 126 species, were found in summer followed by spring i.e. 108 species and autumn 73 species. While, compere to summer, less number of species can be seen in winter season i.e. 64 species (Fig. 3). Most of the herbaceous flora has varied distribution pattern in differe nt seasons. The summer and spring flora is high in number than autumn and winter [20-22].  Raunkiaer (1934) proposed the term "Biological Spectrum" to express both lifeform and distribution of flora and the phytoclimate under which the prevailing lifeforms evolved. The life-form study is thus an important part of vegetation description, ranking next to floristic composition. This study is an important part of the vegetatio n description, ranking next to floris tic composition [23]. Life form and leaf size spectra indicate a climatic and human disturbance of a particular area [24]. The life form and leaf size spectra are benefic ia l attributes that have been broadly used in vegetation description. Furthermore, it is traditionally being used to describe world vegetation types at the community level [8].

Biological spectrum
The life form differences in various societies make up the basis of their structure. Diffe re nt classification of the life forms there, but among them, Raunkiaer 11.2%), followed by nanophanerophytes (10 spp., 8%), while in autumn, the dominant species were microphanerophytes (22 spp., 30.55%) followed by therophytes (15 spp., 20.83%), nanophanerophytes (10 spp., 13.88%), chameophyes (9 spp., 12.5%). The winter is the same as autumn the dominant species were microphaneophytes (22 spp., 34.37%) followed by therophytes (11 spp., 17.18%), nanophaneophytes (10 spp., 15.62%), chaemophytes (9 spp., 14.06%) (         In district Charsadda harsh winter creates unfavourable conditions which resulted in the abundance of these life forms. The locality also confronting a number of threats in the form of overgrazing, soil erosion, construction and agricultura l extension. These factors combined with anthropogenic pressures are a serious threat to local biodiversity. Therefore, proper conservation strategies are the need of the hour to conserve this natural wealth for the generation to come.