To Collect and Identify Orchid Species from Varied Climatic Zones of Himachal Pradesh for Population and Ecological Analysis

There are some 25,000–35,000 species of orchids in the Orchidaceae family, making it the second biggest group of flowering plants (Mabberley, 1997; De and Singh, 2015; De and Medhi, 2017). The distinctive floral morphology, fluffy minute seeds, and relationship with mycorrhiza are distinctive features of this unusual collection of highly developed monocotyledonous plants. Theophrastus first recognized these plants in 285 BC, and ever since then, their beauty and enormous potential have fascinated humans. In reference to the paired tubers seen in terrestrial orchids, the name "orchis"—meaning "testicles" in Greek—is derived from. Orchids are very global, having been found on almost every continent except Antarctica. Almost every habitat on Earth is home to orchids. Orchids may be categorized as epiphytes, lithophytes, terrestrial, or mycoheterotrophs based on their habits, environment, and chances of survival. According to Cribb et al. (2003), around 73% of orchid species are known to be epiphytic. Epiphytes are plants that live on top of other plants or inanimate things; they get their water and nutrients from the air, stem-flow during rainstorms (Awasthi et al., 1995), and plant detritus. In contrast, you may find ground orchids, or terrestrial orchids, in grassland or woodland habitats. Orchids very often exhibit mycoheterotrophy, a natural phenomenon. Throughout their lives, mycohereotrophs rely on mycorrhiza, which are fungal partners, for growth and development (Leake, 2004).

Among the most prominent groups of monocotyledons in terms of size, diversity, and evolutionary history is the Orchidaceae family, which includes the most commercially significant flowering plants—the orchids. As a matter of fact, they are among the most beautiful plant species; they make up 8-10% of flowering plant species and 40% of monocots. Orchids were originally christened by Theophrastus (370–285 B.C.) in his book Enquiry into Plants, although they were referenced often in ancient Indian (Sushrut Sanhita, Charak Sanhita, Ashtangsangraha–600–200 B.C.) and Chinese (Shen-nung’s Materia Medica) literature (cf. Bulpitt, 2005). The orchid family is known for its intricate flower structures that aid in pollination, its stifled endosperm development, and its abundance of tiny seeds with severely diminished embryos that can only germinate when they form a mycorrhizal relationship.

The medicinal and floricultural uses of orchids are well-documented. Orchids have long been hailed as the crown jewels of the cut-flower industry, thanks to their stunning variety of blooms and their ability to retain their beauty for an extended period of time. Nowadays, floriculture centered around orchids is a thriving industry in many countries, including Australia, Thailand, Japan, Singapore, USA, and Malaysia. Orchids are widely used in traditional medicine for a variety of conditions, such as dysentery, hemorrhage, worm infection, pain, and dendrobium teretifolium. This is due to the orchids' high phytochemical content (Toh, 1994; Husen and Rahman, 2003; Lai et al., 2004; Rao, 2004; Bi et al, 2005; Nayak et al., 2005; Jalal et al., 2008a). Cymbidium hybrid, Epipactis helloborine, and Liparis ovata were the sources of the HIV-inhibitory plant lectins (De Clercq, 1994; Balzarini, 2006). Moscatilin, a phytochemical isolated from Dendrobium loddigesii, shown modest anti-cancer effects in vitro against lung and stomach cancer cell lines (Ho, 2003). In addition to their culinary uses, gums, glues, narcotics, essences, fragrances, and even as poisons, orchids have many more practical uses (Lawler, 1984). Most people know orchids for their fragrant oil, vanillin, which is extracted from the green pods of the Vanilla planifolia plant.

Vélez, Leisberth& Jiménez et. al. (2023) - Orchids are among the most endangered plant species, however they are also among the most numerous and important in tropical ecosystems for things like water balance, nutrient cycle, and biomass. Because of the strong correlation between environmental factors and the variety of these organisms, we postulate that local elevation may affect their abundance. One sandstone plateau in the Cordillera del Cóndor contains a great variety of orchid species, and this research evaluated the diversity of orchid species at altitudes of 1200, 1400, and 1700 meters. For every level, three plots of 0.1 hectare were made. There were twenty-five subplots in all, with eight randomly selected from each plot. In these subplots, every species of orchid was counted and recognized. The results revealed a total of 867 individuals, representing 119 species from 54 genera. At an elevation of 1700 meters, there were 63 species, the most at 1400 meters with 52 species, and the fewest at 1200 meters with 39 species. Different orchid species were found at each of the three altitudes due to the much greater humidity levels at roughly 1700 m. The most promising markers of environmental status in this region were 21 species, including Maxillariagrayi, Elleanthusoliganthus, Maxillariamapiriensis, Stelispittieri, and Stelisortegae. In the sandstone plateau forests of the Cordillera del Cóndor's Shagmi Range, we find that height is the main factor restricting orchid populations.

Africa is home to a wide variety of ecosystems, according to Bakayoko, A. et al. (2022). Despite being home to the world's second-largest forest reserve, its flora has received little attention due to a lack of funding for botanical prospecting investigations. Not many families have had their members investigated extensively; for example, the Orchidaceae are mostly unknown. The purpose of this research is to add to our understanding of this family by examining its distribution and use throughout continental sub-Saharan Africa. West Africa, Central Africa, Southern Africa, and East Africa were the four main areas used for the orchid flora investigation, excluding South Africa and North Africa. The literature review provided the groundwork for this research. In order to narrow our focus, we reviewed literature on orchids, local floras, and distribution maps from the studied regions. We managed to compile a list of 1,373 species from 88 different genera. According to the findings, out of the four phytogeographic zones, Central Africa has the most species (708), followed by Southern Africa (637), and East Africa (583). Among the world's regions, West Africa has the fewest species, with 413. The list of uses is somewhat extensive. Orchids are most often used as decorative plants, in food, and in pharmacopoeia. Tanzania, Zimbabwe, the Democratic Republic of the Congo, Mozambique, Zambia, Malawi, Rwanda, Angola, Gabon, Central African Republic, Uganda, Burundi, and Kenya were among the nations where endemism was confirmed.

Vitt, P., Taylor, A., Rakosy, D. et al. (2023), Global conservation prioritizing for well-studied species, such birds, mammals, and amphibians, is based on quantitative estimates of endemism, evolutionary uniqueness, and extinction hazard. Nevertheless, the majority of the world's taxa do not have access to such data. An example of this is the Orchidaceae family, which is known for its extreme diversity and global reach yet has few data on its evolutionary history and potential dangers. We provide a framework for defining conservation priorities using phylogenetic and taxonomic criteria of uniqueness and rarity according to the number of regions and the area of habitation. The Neotropics are characterized as hotspots for richness for 25,434 orchid species with distribution data (89.3% of the Orchidaceae), whereas New Guinea is characterized as a hotspot for evolutionary uniqueness. Several islands are found to have several rare and unusual species. Although there are fewer monotypic genera in orchids than in other Angiosperms, a greater number of taxonomically unique orchid species are located in only one area. We locate 278 species that need conservation efforts right now, and we find that over 70% of those species are not protected in ex-situ collections at botanical gardens nor have an IUCN conservation assessment. Our research sheds light on orchid hotspots and species that are critically endangered, while also providing a foundation for future studies of other taxa with less data.

Morato and Danielle (2023) - The genus Euglossini includes the orchid bee as one of its subspecies. The variety and quantity of these bees are often higher in areas with more plant cover. The researchers in this study set out to figure out what effect deforestation has on euglossine bee populations in the Rio Branco municipality area of Acre State and the neighboring regions. Ten randomly selected forest sections of varying sizes were classified as either rural or urban for the purposes of the research. Bee samples were collected between 2005 and 2006. Of the 3,675 bees that were gathered, 36 were of different species and 4 were of different genera. When comparing bee populations in urban and rural areas, no statistically significant difference was found. An indicator of bee variety and abundance was the index of edge in fragments. Additionally, species richness might be reliably predicted by the projected connectedness. The faunal composition of pieces was more comparable when there was a significant degree of similarity in the landscape structure of those pieces.

Guy Chiron (2019) - Species endemism and species richness are two complementary concepts that are often used to assess biodiversity. When used to demarcate protected areas, they may prove to be useful tools. The present inquiry is based on these beliefs, which are based on the Baptistonia genus of orchids, which are peculiar to the Brazilian Atlantic Forest. From the species richness investigation, we can determine that there is one highly rich location (the Serra do Castelo, ES) and six wealthy places in general. There are three of these areas where the endemism index is more than 1. When it comes to protecting biodiversity, the eight spots on the list are crucial. Hierarchical endemism links across nine phytogeographical zones are evaluated using a parsimony analysis of endemicity. By examining the genus Baptistonia's phylogenetic connections, this study verifies two things: (a) the southern Atlantic Forest is home to two major endemism centers, and (b) the Serra do Castelo seems to represent the genus's center of diversification.

The location of the present research in the state of Himachal Pradesh. The location in the northwest Himalayas, with its undulating terrain and heights ranging from 350 to 7000 meters above sea level, lies between the coordinates of 30°22′ and 33°12′ North latitudes and 75°47′ and 79°04′ East longitudes. From 2010 to 2013, researchers in Himachal Pradesh conducted periodic field surveys to identify orchids in four distinct climate zones: subtropical, warm temperate, cold temperate, subalpine, and alpine. A total of 78 locations spread over nine districts were sampled, with elevations ranging from 643 to 3979 meters. The data collection was carried out in 30 quadrats per location, with 10 1×1 m quadrats placed inside each transect at a distance of around 50 m. The data used to compile the findings in the following chapter came from at least 120 and no more than 180 quadrats. The moisture content of soil was determined by Oven dry method (Allen et al., 1974). 10g of freshly collected soil sample was kept in a hot air oven at 105ºC for 24 hrs. Genetic similarities and distances were calculated between all pairs based on the method of Sneath and Sokal (1973). Isoenzyme genotypes of different morphotypes were compared at each locus to find out genetic variability.

Orchid species studied in different localities

From 2010 to 2013, a total of 39 orchid species belonging to 23 genera were gathered in Himachal Pradesh for the purpose of this research (Table 1).

Table 1: Orchid Species Collected from Himachal Pradesh (2010–2013)

Ten different tribes and three distinct subfamilies make them up (Cameron et al., 1999). The tribe Cypripedieae only had one species, Cypripedium cordigerum, representing the Cypripedioideae family. In the family Orchidoideae, there were twelve genera and twenty-four species: Androcorys, Brachycorythis, Dactylorhiza, Dithrix, Goodyera, Habenaria, Herminium, Pecteilis, Peristylus, Platanthera, Satyrium, and Spiranthes. The tribes Cranichideae and Diseae were furthermore included. In contrast, fourteen species belonged to 10 genera in the family Epidendroideae, which included the following: Crepidium, Cymbidium, Dienia, Epipactis, Eulophia, Gastrochilus, Gastrodia, Liparis, Oreorchis, and Rhynchostylis (Fig. 1).

Figure 1. Numerical strength of different subfamilies in terms of tribes, genera and species

New to the state flora are two species of Orchidoid, Habenaria aitchisonii and H. pubescens. The 78 locations around the state were included in the collection, and the altitude range was from 643 to 3979 meters. Out of all the places that were examined at the moment, Taradevi (Shimla) has the most diversity. The largest genus was Habenaria, which had nine species. Fifteen genera with one species each were represented, including Androcorys, Brachycorythis, Crepidium, Cymbidium, Cypripedium, Dactylorhiza, Dienia, Dithrix, Gastrochilus, Gastrodia, Pecteilis, Peristylus, Rhynchostylis, Satyrium, and Spiranthes (Fig. 2).

Figure 2. Numerical strength of different genera in terms of species

Species habits, distribution pattern and habitats

The ground-dwelling habits of all species except two were documented in Table 1: Gastrochilus calceolaris and Rhynchostylis retusa. The leafless mycoheterotrophic life form was shown by two terrestrial species, though: Cymbidium macrorhizon and Gastrodia falconeri.

Orchids in the study region had a wide variety of distribution patterns, each reflecting the specific climate needs of the plant species. The cold temperate (1800-3000m) and warm temperate (900-1800m) climates were home to the vast majority of the species, including both mycoheterotrophs. In most cases, they emerge during or just after monsoon rains, produce fruit and flowers, and then die off as winter draws near. Rhizomes, pseudobulbs, and tubers were some of the organs they used to endure bad times for a long time. These two epiphytic species grow best on broad-leaved trees with fissured bark and are thus limited to the subtropical to mild temperate zones (up to 1800 m).

Geographical affinities of the species

The orchid species studied presently showed greater affinities with those of adjacent areas and none of these was found to be endemic to the state of Himachal Pradesh. All of them are on record from different parts of northwest Himalaya and adjoining plains.

Table 2: Frequency, Density and Abundance of Orchid Species

Three species (Androcorys monophylla, Goodyera biflora, Oreorchis indica) are restricted in distribution to Northwest Himalaya, whereas the others extend their distribution to other adjacent regions as well. All of the species find distribution in adjoining state of Uttarakhand. Twenty-five species occur in Jammu and Kashmir and one of them (Spiranthes sinensis) in the adjacent plains of Haryana. Thirty-three species occur in the Central (Nepal) Himalaya, 36 in Eastern Himalaya/ Northeast India, and ten species find distribution in the southern (peninsular) region of the country; two of which (the epiphytic Gastrochilus calceolaris and Rhynchostylis retusa) are well reported from Andaman and Nicobar Islands. As many as 20 species extend to Bhutan, six to Bangladesh, 23 to Pakistan, four to Afghanistan, 10 to Myanmar, 19 to China, and 14 to Thailand (Fig. 3).

Figure 3. Geographical affinities of orchid species

Flowering and fruiting periods

All of the presently studied orchids possessed beautiful flowers (Figs. 4). Majority of them came into flower during the months of July (28 species) and August (26 species). The number of species in bloom progressively declines towards both sides of these months; none of the species was observed in flowering during the months of November, December, January and February. Fruit formation took one to one and a half month after the beginning of flowering; maximum fruit set (26 species) was seen during the month of August. The fruit set was not found similar in all of the presently studied species and it ranged between 60-90% in majority of cases. The lowest (26.45%) fruit set was seen in Crepidium acuminatum and the highest (96.26%) in Rhynchostylis retusa. Fruit dehiscence and seed dispersal was complete before the onset of winter season.