Journal of Threatened Taxa | www.threatenedtaxa.org | 26 November 2022 | 14(11): 22086–22097

 

ISSN 0974-7907 (Online) | ISSN 0974-7893 (Print) 

https://doi.org/10.11609/jott.7861.14.11.22086-22097

#7861 | Received 01 February 2022 | Final received 16 November 2022 | Finally accepted 20 November 2022

 

 

A comparative analysis of the past and present occurrences of some species of Paphiopedilum (Orchidaceae) in northeastern India using MaxEnt and GeoCAT

 

Debonina Dutta 1  & Aparajita De 2

 

1,2 Department of Ecology and Environmental Science, Assam University, Silchar, Assam 788011, India.

1 deboninadtt@gmail.com, 2 aparajitade.ecology@gmail.com (corresponding author)

 

 

 

Editor: Pankaj Kumar, Kadoorie Farm and Botanic Garden Corporation, Hong Kong S.A.R., P.R. China.            Date of publication: 26 November 2022 (online & print)

 

Citation: Dutta, D. & A. De (2022). A comparative analysis of the past and present occurrences of some species of Paphiopedilum (Orchidaceae) in northeastern India using MaxEnt and GeoCAT. Journal of Threatened Taxa 14(11): 22086–22097. https://doi.org/10.11609/jott.7861.14.11.22086-22097

 

Copyright: © Dutta & De 2022. Creative Commons Attribution 4.0 International License.  JoTT allows unrestricted use, reproduction, and distribution of this article in any medium by providing adequate credit to the author(s) and the source of publication.

 

Funding: DBT (BT/ENV/BC/01/2010 & 23rd March 2012).

 

Competing interests: The authors declare no competing interests.

 

Author details: Debonina Dutta is currently pursuing her PhD. Her research interest includes the study of few selected species of Paphiopedilum genus in northeastern India and their conservation using biotechnological tools. Aparajita De is a professor. She has specialized in forest ecology, RS, and GIS applications in forest ecology and ethnobiology.

 

Author contributions: DD carried out the fieldwork and drafted the manuscript. AD provided guidance to conduct the field surveys and has reviewed and corrected the manuscript.

 

Acknowledgements: We would like to express our sincere gratitude to Department of Ecology and Environmental Science, Assam University, Silchar and The Botanical Survey of India, Eastern Regional Circle. We are grateful to the Department of Biotechnology, Govt. of India for providing financial support for the study. We are thankful to the director, BSI, Dr A.A. Mao and we convey our special regards to Dr N. Odyuo, head of office, BSI, Eastern Regional Circle, Shillong. We are thankful to Dr. Dibyendu Adhikari, principal scientist, National Botanical Research Institute for critically going through the manuscript and suggesting improvements. We are also thankful to the Dr D.K. Agarwala, BSI Gangtok. We are thankful to Miss Dukmit Lepcha, Bantei Thyrniang, M.A.M. Saikia, and Dr. Batskhem Myrboh, assistant professor, Synod College, for helping us in our field study. We duly acknowledge the following scientists who provided herbarium related information: Dr. R.K. Gupta, in-charge, Central National Herbarium, Kolkata; Dr. Anup Chandra, head, Botany Branch, Forest Research Institute, Dehradun.

 

 

 

Abstract: Members of the genus Paphiopedilum are well known for their long-lasting unique flowers. They are becoming rare due to over-collection and habitat loss because of human disturbances and deforestation. The present study aimed to compare the past and present occurrences of the genus Paphiopedilum in northeastern India using MaxEnt and GeoCAT. A historical occurrence model (HOM) was prepared using secondary data, and an actual occurrence model (AOM) was constructed with primary field data. The HOM and AOM revealed that bioclimatic factors, topography and precipitation play a significant role in the survival of Paphiopedilum populations in northeastern India in both the current and historical distributions. The other vital environmental variables were elevation (h_dem), mean diurnal range (bio_2), annual mean temperature (bio_1), temperature annual range (bio_5) and annual precipitation (bio_12). The results showed a sharp decline in the extent of occurrence and the area of occupancy of Paphiopedilum in the study area. The extent of occurrence and area of occupancy for HOM were 170,972 km2 and 18 km2. For the AOM, they were 125,315 km2 and 12 km2, respectively. The HOM model indicated that Paphiopedilum was earlier growing sporadically. On the other hand, the AOM result indicates that it is presently growing sparsely in isolated pockets that are more prone to extinction. Paphiopedilum can be conserved successfully using an integrative conservation approach, comprising ecological modeling techniques to search for additional locations, ex situ propagation techniques, and possible reintroduction in selected areas. 

 

Keywords: Ecological niche modeling, environmental variables, lady slipper orchids, orchid conservation.

 

 

 

Introduction

 

Predictive habitat distribution models are being used extensively in ecology as they can statistically relate the geographic distribution of species or communities to their environment (Guisan & Zimmermann 2000). These models correlate known species occurrence with climatic data available for relevant areas to determine the boundaries of the multidimensional range of the species. By projecting such conditions onto geographical space, one can predict the potential distribution of the target species. These techniques are applied in a wide variety of studies to: 1. predict the distribution of rare, threatened, or invasive species (Serra et al. 2012; Silva et al. 2013, 2014; Deka et al. 2018), 2. optimize future faunal/floristic surveys (De Siqueira et al. 2009), and 3. inform the establishment of future protected areas (Nóbrega & De Marco Jr 2011).

Studies related to species distribution models have been conducted for the family Orchidaceae by many workers (Kolanowaska & Konowalik 2014; Kolanowska & Busse 2020). Orchids are one of the most threatened group of plants as their complex life history makes them particularly vulnerable to global environmental change. There are more than 1,200 genera of orchids reported in India (Misra 2019; Singh et al. 2019; Schuiteman 2022). The present study tries to model the current distribution of the genus Paphiopedilum, family Orchidaceae in northeastern India, and compare it with the historical occurrence data depicting its distribution in the past. The genus Paphiopedilum is highly preferred in the horticultural market for its exotic, large flowers on small plants (Cribb 1998). A few species are regarded as threatened or even extinct in the wild due to over-collection from natural areas and large-scale illegal trade (Long et al. 2010). The genus Paphiopedilum is listed in Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES 2022).  All the species under the genus Paphiopedilum found in India come under the category of Vulnerable to Critically Endangered according to the IUCN Red List of Threatened Species (IUCNredlist.org/2021-3) (Table 1). Due to its high horticultural importance (Zhen et al. 2006), the genus faces extensive collection pressure from the wild. This, along with the rapid degradation of its habitat has led to the drastic reduction in the population of the genus (Cribb 1998).

Nine species of Paphiopedilums have been reported from India: Paphiopedilum druryi (Bedd.) Stein, growing at an altitudinal range 1,400─1,550 m, Paphiopedilum fairrieanum (Lindl.) Stein growing at 200─1,200 m, Paphiopedilum venustum (Wall. ex Sims) Pfitzer at 500─1,500 m, Paphiopedilum wardii (Summerh.) at 1,200─2,500 m, Paphiopedilum villosum (Lindl.) Stein at 1,300─2,200 m, Paphiopedilum insigne (Wall. ex Lindl.) Pfitzer at 1,000─1,500 m, Paphiopedilum charlesworthii (Rolfe) Pfitzer at 1,200─1,600 m, Paphiopedilum spicerianum (Rchb.f.) Pfitzer at 300─1,400 m and Paphiopedilum hirsutissimum (Lindl. ex Hook.) Stein at 200─1,800 m. Eight species are found in the eastern Himalaya and northeastern India, and one in southern India (Hajra & De 2009; Chowdhery 2015). All the species of this genus found in northeastern India have been reported to grow at altitudes of 200─2,200 m. Several species of Paphiopedilum are found growing in shady vertical/ limestone cliffs at varying altitudes (Averyanov 2007; Averyanov et al. 2014; Gurung et al. 2019).

The present work deals with the following objectives: estimation of the past and the present distribution status of some Paphiopedilum orchids in northeastern India, estimation of changes in the area and the extent of occurrence of Paphiopedilum spp. (if any), and determination of the environmental variables that are vital to the distribution of the genus.

 

Study area

Northeastern India comprises the eastern part of the Himalayan range, intercepted by plains, valleys, and hilly terrains (Yadava 1990). Our study was carried out in Meghalaya, Mizoram, Arunachal Pradesh, Sikkim, Nagaland, and Assam (Figure 1). The following species of Paphiopedilum were recorded in the present study, viz, P.  spicerianum, P. venustum, P. insigne, P. fairreanum, and P. hirsutissimum.

 

 

Materials and Methods

 

Study design

Ecological niche models (ENM) were prepared using maximum entropy modelling (MaxEnt) of species geographic distributions (Phillips et al. 2006). The version 3.3 of MaxEnt was used for the current study. We executed two models for our study. Past and present data were divided into historical occurrence points and actual occurrence points. Model 1 was executed using the Historical occurrence points. Historical occurrence data of Paphiopedilum were obtained from the recorded historical data such as herbarium records (Kew Herbarium catalogue 2022; Museum National D histoire Naturelle 2022; GBIF 2022; Natural History Museum 2022) and published literature (Table 2). We have named it as historical occurrence model (HOM) in this paper. Model 2 was executed using the actual occurrence data (Table 3). Therefore, model 2 is referred to as the actual occurrence model (AOM).

The results obtained from the ecological niche model were verified in the study area during the period of 2015─2021. The details of the historical presence sites and actual presence sites are given in the Table 2 & 3. Based on the ENM observations, the area of occupancy (AOO) & extent of occurrence (EOO) of historical and actual occurrence data of Paphiopedilum were estimated. The estimation of AOO & EOO were performed using Geospatial Conservation Assessment Tool (GeoCAT), calculated at a 1 km2 area cell size. Figure 2 gives the details of the study design.

 

Data collection

Historical data were collected from various herbaria (both offline and online) and literature sources. Occurrence data of Paphiopedilum was obtained from herbaria of the Botanical Survey of India, ERC, Shillong (Assam), Global Biodiversity Information Facility (GBIF), Central National Herbarium (CAL), Forest Research Institute, Dehradun (DD), Botanical Survey of India, Arunachal Pradesh Regional Centre (ARUN), Natural History Museum (NHM), Museum National d’Histoire Naturelle (MNHN) and Kew herbarium (KEW) (Table 2). The previous occurrence reports were also noted from the literature survey (Pradhan 1971; Pradhan 1975; Pradhan 1976, 1979; Kataki et al. 1984; Bose et al. 1999; Lucksom 2007; Misra 2007; Russel 2008a,b; Mao 2010; Bhattacharjee et al. 2018). The records obtained from literature reviews were used for cross-referencing with the reported locations of herbarium collections. Further the herbaria collections having location information (nearby village name or landmark) were tagged and digitized with the help of Google Earth following Milagros & Funk (2010).

AOM was prepared from the primary data. The primary data were collected from field visits to respective localities of different states (Table 3). The field surveys were conducted by snowball sampling method (Spreen 1992; Johnson 2014). The flowers of each species growing on the cliff were identified using a binocular. Geo -coordinates of the location were recorded using GPS (Garmin etrex 20) and the habitat features were recorded. The accessible sites were thoroughly surveyed for a closer view of the habitat.

 

Environmental variables

The dataset for ENM include NDVI (Normalized differential vegetation index), bioclimatic variables, and hydrological variables (i.e., slope, aspect, topography, and elevation). A total of 12 environmental variables were selected for the study.  Table 4 shows the list of the final selected variables for the present study.

The environmental variables were applied with principal component analysis (PCA) to avoid multi-co linearity (correlation among the variables that could create redundancy in models) (Chaudhary et al. 2021). The bioclimatic layers in ASCII format were used with a resolution of 30 ARC seconds for this study. The variables for the area of interest were obtained by masking the bioclimatic rosters with the boundary of northeastern India using ArcView. Highly correlated variables were excluded by performing a Pearson correlation test of variables exhibiting a value of r <0.9 (i.e., 90%). A total of 12 environmental variables were used post correlation (Table 4).

 

 

Results

 

A total of 40 specimens were obtained from various herbaria in India and other countries (Table 2). During the present study, we located five species of Paphiopedilum in different sites of the study area (Table 3). They were P. spicerianum, P. insigne, P. fairreanum, P. venustum, and P. hirsutissimum. A total of 16 actual occurrence sites were recorded for the five species. Image 1 shows the habitat of a few Paphiopedilum species. The two ecological niche models were executed based on this data and the results obtained are given as follows.

 

Historical occurrence model and actual occurrence model

Two models were obtained using the historical occurrence data and actual occurrence data. The ENM models are represented in Figure 3. Model 1 or HOM represents the historical occurrence distribution of Paphiopedilum, and model 2 or AOM represents the actual occurrence distribution of Paphiopedilum in northeastern India.

 

AUC and jackknife interpretation

The model calibration test for Paphiopedilum yielded satisfactory results for both models. The red line shows the ‘fit’ of the model to the training data, and the blue line indicates the ‘fit’ of the model to the testing data (Figure 4). The area under the curve (AUC) value of each model aids in the assessment of the model quality. In the jackknife of AUC, the blue line depicts the real test of the predictive power of the MaxEnt model. An AUC value above 0.9 (closer to 1.0) indicates a good model performance. The AUC values for HOM (AUCtest = 0.972 ± 0.015) and AOM (AUCtest = 0.942 ± 0.015) therefore indicated that the model performance was good in both cases.

The significance of environmental variables on each model was assessed by interpretation of the jackknife of AUC (Figure 5). The contribution of the environmental variables on the model build was assessed from the percent contribution of variables and permutation importance (Table 5). Among all the variables, bio_2 (mean diurnal range) and bio_1 (annual mean temperature) were the most influential variables in the build of HOM as evident from the percent contribution of the variables in model build. The variable bio_2 contributed 46.6% and bio_1 contributed 19.3% respectively on HOM (Table 5). According to the internal jackknife of AUC for HOM, bio_1 (annual mean temperature) has the highest contribution to the model, followed by h_dem (elevation) (Figure 5). Jackknife of AUC shows the contribution of environmental variables in both models. The variables collectively contributed 100% to the HOM. Aspect (h_aspect) and topographic index (h_topoind) contributed 19.1% and 0.7% (Table 5). Considering the permutation importance, bio_5 contributed the highest (55.3%) to the model, followed by h_dem (27. 5%) and bio_2 (8. 9%) (Table 5). The variable bio_2 was the most influential environmental variable in the model build of HOM.

The percent contribution of variables in the model build of AOM revealed that bio_12 (annual precipitation) and bio_2 (mean diurnal range) were most influential in the model build. Bio_12 contributed 41.9% and bio_2 contributed 29.1% to the model build. The variable bio_2 was followed by bio_5 (max temperature of the warmest month) that contributed 24.4%, and h_topoind contributed 3.9% to the AOM. Considering the permutation importance, bio_5 contributed 53.1%. Jackknife of AOM infers the highest contribution of h_topoind and bio_14 (precipitation of driest month), followed by bio_2 (mean diurnal range) and bio_12 (annual precipitation). Amongst the bioclimatic factors, bio_12 showed the highest contribution to the build of AOM (Table 5).

 

Potential habitat areas and actual habitat areas of Paphiopedilum spp.

Figure 3 shows the Ecological niche model for HOM and AOM. The figure depicts the probable habitats in different colours. Areas in red are the highest potential areas for the distribution of Paphiopedilum. Yellow represents areas with medium potential whereas the low potential areas are represented by green; 40 secondary occurrence records (historical occurrence records) were recorded from literature and herbarium sources (Table 2). However, the field survey results revealed 16 actual occurrence records of the Paphiopedilum spp. in the study area (Table 3).

 

EOO & AOO of the genus Paphiopedilum

HOM shows the distribution regions of Paphiopedilum in Assam, Mizoram, Meghalaya, Sikkim, Arunachal Pradesh, Nagaland, and Manipur. However, according to AOM, the distribution of Paphiopedilum is found in all the states of northeastern India, found in HOM except Assam (Table 6). The EOO and the AOO for HOM of Paphiopedilum were 170,972 km2 and 18 km2. EOO and AOO for the AOM were 125,315 km2 and 12 km2.

 

 

DISCUSSION

 

Ecological niche modeling has efficiently predicted the potential population areas of the genus in this study. The high AUC values for training and testing (˃ 0.90) infer the high efficiency of the niche model to differentiate between presence and absence areas for the species.

In the Table 6, a comparison between the historical presence sites and actual presence sites obtained through ENM survey is presented. This comparison revealed the high predictive value of the model. It, therefore, provides a check on the accuracy and reliability of the ENM model in the present study.

 

Significant environmental variables determining the distribution of Paphiopedilum

According to the jackknife model and the percent contribution of variables in model build, the parameter bio_2 (mean diurnal range) shows the highest contribution to the build of HOM (Table 5). The variable bio_2 infers to the mean of monthly temperatures (max temperature-min temperature). It contributes 46.6% to the model build of HOM, indicating the high importance of the mean temperature in the growth of the orchids of this genus.

In the AOM, bio_12 is the most significant variable in the jackknife interpretation of the model (Figure 5). The variable bio_12 indicates the annual precipitation in the model build. The bio_12 variable is followed by bio_2 (mean diurnal range) and bio_5 (max temperature of the warmest month). These results indicate that temperature and rainfall are two important contributors that determine the availability of the members of genus Paphiopedilum. The field observations also correlate the importance of precipitation and temperature requirements of Paphiopedilum.

All the species of this genus found in northeastern India are found between an altitude of 200─2,200 m, which shows importance of h_dem (digital elevation model) being one of the highest contributing variables of the internal jackknife of HOM (Figure 5, Table 5). Similarly, mean temperature, mean diurnal range, max temperature of the warmest month and annual precipitation play a significant role in the model execution of Paphiopedilum in both HOM and AOM.

Other workers have also studied the dependence of the survival, reproduction, and germination of different plant species on temperature and precipitation. For instance, Wilkie et al. (2008) reported the influence of low temperatures (vernalization), seasonal variations in temperature, photoperiod, and water stress on the flowering of plants (Wilkie et al. 2008). In another study, inadequate temperature conditions during endodormancy compromised flowering or led to erratic and longer flowering duration with morphological disorders and flower necrosis (Rodrigo & Herrero 2002).

 

AOO, EOO concerning the past and present distribution of Paphiopedilum

Comparison of both models shows that the species distribution of Paphiopedilum has undergone a sharp decline over the past two decades. Field observations also indicate highly fragmented populations. All the species of this genus have very few individuals in the study area. A reduction in the extent of occurrence (EOO) and area of occupancy (AOO) was observed in the AOM compared to the HOM. During the field survey no species was located in the earlier reported sites of Assam (Table 6).

The reduction in AOO could be due to factors like over-collection, climate change, urbanisation, unplanned development, and habitat fragmentation. An increased frequency of large-scale disturbances caused by extreme weather events is known to cause increasing gaps and an overall contraction of the distribution range, particularly in areas with relatively low levels of spatial cohesion (Paul & Wascher 2004).

Effects of habitat fragmentation on the persistence of populations and species play a major role in conservation biology (Reed & Frankham 2003). Limitations of plant species dispersal also affect plant colonization (Olivier et al. 2002). Small population sizes, lead to decreased population fitness and eventually make the small population sizes more vulnerable to extinction (Reed & Frankham 2003; Reed 2005, 2008). The field studies revealed that the populations of Paphiopedilum had very few individuals. The habitat was also highly fragmented. These factors are further exacerbating the risk of extinction of the genus.

It was observed that Paphiopedilum grew in the rock crevices of east-facing slopes of the habitats situated in the hilly terrains (Image 1). They also grew in the space between tree roots and rock layers of the habitat substratum. The prolonged filling of the conjoining rock fissures between the rock crevices and tree roots by the dry leaves and soil organic matter of the forests provide an excellent growth medium for these orchids in the otherwise soil-deprived cliff sides (Phillips 2017).

 

 

Conclusion

 

In this study, the present status of Paphiopedilum in northeastern India has been determined using ENM-based surveys combined with historical data. The herbarium data provided location history from 1857 onwards (Table 2), while the field data helped in the present assessment of the genus. There was a significant reduction in the EOO and AOO in the actual model as compared with the historical model. The results of the model reveal that temperature and precipitation are the highest contributing factors determining its availability. We were unable to locate the plants in many locations that were earlier mentioned by previous workers. Therefore, it can be inferred that change in the temperature and precipitation patterns in many locations have led to its scarcity.  However, this inference needs to be further corroborated with detailed records of the climate parameter.

These orchids are becoming increasingly rare mainly due to over collection from the wild, rising urbanization causing habitat destruction and also global warming (Swarts & Dixon 2009; Seaton et al. 2010; Barman & Devadas 2013; Ye et al. 2021). Favorable climatic conditions, access to wild habitat sites, and a conducive environment are important for the survival of plants (Hulme 2005; Ballantyne & Pickering 2015; Wraith & Pickering 2018; Li et al. 2020; Ye et al. 2021). The comparison of environmental requirements of the distribution of Paphiopedilum over the years imparts an understanding of the adaptability of these orchids with changing environmental conditions. The dwindling population size of the various species under the genus is increasing the risk of extinction of the already sparse populations in the study area. The over-collection of the Paphiopedilum flowers from the wild for its high market demand results in further habitat loss. Forest road constructions and urbanization also cause further degradation of the Paphiopedilum habitats in different areas of Northeast India. Such reasons have caused the Paphiopedilum orchids to become increasingly rare with time.

Ex situ conservation techniques for mass production of the species with higher market demand could reduce collection pressure on already dwindling wild populations in northeastern India. Paphiopedilum orchids are being propagated elsewhere in the world using various techniques (Huang 1988; Hong et al. 2008; Ng & Saleh 2011). Various individuals have been reintroduced into other suitable habitats by various workers in China (Yang et al. 2020; Gao et al. 2020). Since, in situ conservation is not a viable approach in many locations due to their habitat degradation and other developmental pressures, reintroduction into potential habitats will aid in conservation of the species. We recommend that reintroduction of Paphiopedilum orchids should be conducted on a large scale by both government and non-governmental agencies in northeastern India. We recommend the conservation of Paphiopedilum orchids using an integrative conservation approach of ecological niche modeling to search for additional locations, ex situ propagation techniques, and possible reintroduction in selected areas. Such schemes can be helpful to meet the market demands of Paphiopedilum orchids and boost the conservation of wild populations in northeastern India.

 

 

Table 1. The threat category of genus Paphiopedilum (IUCN: Ver.2021─3)

Name

Threat category

Population trend

P. druryi

Critically endangered

Decreasing

P. fairrieanum

Critically endangered

Decreasing

P. venustum

Endangered

Decreasing

P. wardii

Endangered

Decreasing

P. villosum

Vulnerable

Decreasing

P. insigne

Endangered

Decreasing

P. charlesworthii

Endangered

Decreasing

P. spicerianum

Endangered

Decreasing

P. hirsutissimum

Vulnerable

Decreasing

 

 

Table 2. Historical occurrence records of Paphiopedilum spp.

 

Species

Year

Location

Herbarium source

1

P. fairreanum

1857

NA

Royal Botanic garden, Kew

2

P. insigne

1859

Mount Khasia, Meghalaya

Museum National d’Histoire Naturelle

3

P. venustum

1893

Sonai, Assam

Natural History Museum

4

P. venustum

1893

Sikkim Himalaya

Natural History Museum

5

P. insigne

1894

Cherrapunjee, Meghalaya

Central National Herbarium, Kolkata

6

P. insigne

1899

Shella, Meghalaya

Central National Herbarium, Kolkata

7

P. insigne

1899

Jaintia hills, Meghalaya

Central National Herbarium, Kolkata

8

P. insigne

1899

Jaintia hills, Meghalaya

Bavarian Natural History Collections (SNSB-GBIF)

9

P. venustum

1899

Lingzah Tolung,North Sikkim

Naturalis Biodiversity Center (GBIF)

10

P. venustum

1899

Sikkim

Harvard University Herbaria (GBIF)

11

P. fairreanum

1941

Rohlu, Sikkim

Central National Herbarium, Kolkata

12

P. insigne

1944

Smit, Meghalaya

Natural History Museum

13

P. venustum

1952

Cherrapunjee, Mount Khasia, Meghalaya

Naturalis Biodiversity Center (GBIF)

14

P. venustum

1952

Khasia hills, Meghalaya

Museum National d’Histoire Naturelle, ,

15

P. fairreanum

1957

Dirang dzong, Arunachal Pradesh

Central National Herbarium, Kolkata

16

P. hirsutissimum

1962

Khasi hills,  Meghalaya

Central National Herbarium, Kolkata

17

P. villosum

1963

Cultivated plant

Central National Herbarium, Kolkata

18

P. spicerianum

1972

National orchidarium

BSI-ERC, Shillong

19

P. fairreanum

1974

Tenga Valley, Arunachal Pradesh

BSI-ERC, Shillong

20

P. insigne

1974

Mount Khasia, Meghalaya

Natural History Museum

21

P. insigne

1974

Mount Khasia, Meghalaya

Museum National d’Histoire Naturelle

22

P. insigne

1975

Khasia Mountains

Royal Botanic Garden, Kew

23

P. villosum

1976

Lunglei, Mizoram

Forest research Institute, Dehradun

24

P. fairreanum

1978

Jameri, Arunachal Pradesh

Forest research Institute, Dehradun

25

P. venustum

1984

Khasya hills, Meghalaya

Royal Botanic Garden, Kew

26

P. venustum

1984

Sikkim Himalaya

Royal Botanic Garden, Kew

27

P. venustum

1993

Khasia hills, Meghalaya

Museum National d’Histoire Naturelle

28

P. hirsutissimum

2006

Maram, Manipur

BSI-ERC, Shillong

29

P. insigne

2016

Sohra, Meghalaya

iNaturalist (GBIF)

30

P. fairreanum

2017

Arunachal Pradesh

Wildlife Institude of India (GBIF)

31

P. venustum

2019

East Khasi Hills, Meghalaya

University of Michigan Herbarium (GBIF)

32

P. hirsutissimum

2019

Senapati, Manipur

University of Michigan Herbarium (GBIF)

33

P. hirsutissimum

NA

 NA

Royal Botanic Garden, Kew

34

P. fairreanum

NA

Rupa bridge, Arunachal Pradesh

Central National Herbarium, Kolkata

35

P. fairreanum

NA

Gochum, Rupa

BSI-ERC, Shillong

36

P. insigne

NA

Khasiya mountains

Royal Botanic Garden, Kew

37

P. villosum

NA

Sairep, Mizoram

BSI-ERC, Shillong

38

P. insigne

NA

Khasi hills, Meghalaya

Central National Herbarium, Kolkata

39

P. spicerianum

NA

Cachar, Assam

Central National Herbarium, Kolkata

40

P. hirsutissimum

NA

Naga hills. Nagaland

Central National Herbarium, Kolkata

 

 

Table 3. Actual occurrence records of Paphiopedilum spp.

 

Species

State

Locality

District

1.

P. spicerianum

Mizoram

Lengpui

Mammit

2.

P. insigne

Meghalaya

Laimotsiang

East Khasi Hills

3.

P. insigne

Meghalaya

Latara

East Khasi Hills

4.

P. insigne

Meghalaya

Mawlyndiar

East Khasi Hills

5.

P. insigne

Meghalaya

Mawlyndiar (Liewla)

East Khasi Hills

6.

P. insigne

Meghalaya

Sohra (Nohkalikai)

East Khasi Hills

7.

P. venustum

Arunachal Pradesh

Dirang

West Kameng

8.

P. venustum

Meghalaya

Sohra

East Khasi Hills

9.

P. fairreanum

Arunachal Pradesh

Dirang

West Kameng

10.

P. fairreanum

Arunachal Pradesh

Dirang

West Kameng

11.

P. fairreanum

Arunachal Pradesh

Tenga

West Kameng

12.

P. fairreanum

Arunachal Pradesh

 

Rupa

West Kameng

13.

P. venustum

Sikkim

Upper Dzongu

North Sikkim

14.

P.hirsutissimum

Nagaland

Tobu

Mon

15.

P.hirsutissimum

Nagaland

Meluri

Phek

16.

P. venustum

Sikkim

Mangan

North Sikkim

 

 

Table 4. List of environmental variables.

 

Variable

Description

1.

Bio_1

Annual mean temperature

2.

Bio_2

Mean Diurnal Range (mean of monthly (max temp – min temp))

3.

Bio_3

Isothermality (P2/P7)*(100)

4.

Bio_4

Temperature Seasonality (standard deviation *100)

5.

Bio_5

Max temperature of the warmest month

6.

Bio_12

Annual precipitation

7.

Bio_14

Precipitation of Driest Month

8.

Bio_15

Precipitation of Seasonality (coefficient of variation)

9.

h_dem

Digital elevation model

10.

h_ topoind

Topographic index

11.

h_aspect

Aspect

12.

h_slope

Slope

 

 

Table 5. Percent contribution of variables in model build.

Percent contribution of variable in Historical occurrence model

Percent contribution of variables in Actual occurrence model

Variable

Percent contribution

Permutation importance

Variable

Percent contribution

Permutation importance

bio_2

46.6

8.9

bio_12

41.9

0

bio_1

19.3

0

bio_2

29.1

43.1

h_aspect

19.1

6.6

bio_5

24.4

53.1

h_dem

6

27.5

h_topoind

3.9

3.8

bio_14

4.3

0.2

bio_14

0.7

6.7

bio_5

3.7

55.3

bio_15

0

0

h_topoind

0.7

1.3

h_slope

0

0

bio_12

0.3

0

h_dem

0

0

h_slope

0

0

h_aspect

0

0

 

 

Table 6. Comparison between historical occurrence data and actual presence data.

Species

State

Locality

Source

Nearby Positive sites as per field findings

P. spicerianum

Mizoram

Mammit district

Literature review

Present

Assam

Cachar, Sonai river Bank, Barak river bank, Narpuh WS.

Literature review

Herbarium data

ENM depiction

Not found

P. fairrieanum

Sikkim

Tinkitam

Literature review

Previously presence reported. Habitat Destruction due to ongoing agricultural practices (Jhum cultivation)

P. insigne

Meghalaya

Cherrapunjee, Mawsynram, East Khasi hills

Literature review, Herbarium data, ENM depiction

Present

P. venustum

Sikkim

Beh, Tong, Sanklang (Sikkim)

Literature Review, Herbarium data

Present

Meghalaya

Jaintia Hills

Literature Review, Herbarium data

Not found

P. fairreanum

Arunachal Pradesh

Gacham village, Rupa, Tenga valley

Herbarium data

Present

P. fairreanum

Arunachal Pradesh

Jameri village

Herbarium data

Absent

P. villosum

Mizoram

Sairep, Theiriat, Lunglei

Herbarium data, ENM depiction

Present

P. hirsutissimum

Manipur

Maram

Herbarium data

Not found

 

 

For figures & images - - click here for full PDF

 

 

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