Translator Disclaimer
1 August 2010 Roadside Distribution Patterns of Invasive Alien Plants Along an Altitudinal Gradient in Arunachal Himalaya, India
Author Affiliations +
Abstract

Invasive plants have spread all over the world, including the Himalayan region. In 2009, the distribution pattern of invasive alien plants was studied on 38 plots, from 100 to 4200 m, in Arunachal Pradesh and Assam, India. Eighteen invasive alien plants (frequency >5%) from 7 families were recorded, of which 15 species (83.3%) were from North and South America. The most common plants by both frequency and coverage (>50%) were Ageratum conyzoides, Chromolaena odorata, and Mikania micrantha. Species composition changed with altitude. Thirteen species grew in the tropical zone, 10 in the subtropical, 6 in the temperate. and 1, Taraxacum officinale, in the subalpine zone. We suggest that low temperature and snowfall in the highlands may filter nonadapted species from tropical regions and that recent construction and use of roads facilitate the establishment of invasive alien plants. Although several invasive alien plants were regarded as noxious weeds, local residents in the study area mentioned their beneficial uses: A. conyzoides and Solanum carolinense are used as medicine, Galinsoga quadriradiata is used as a vegetable, and Eichhornia crassipes is used to improve fish growth in aquaculture. Information from scientific assessment and local perception of invasive alien plants will assist in the development of appropriate plant resource management plans in Arunachal Himalaya.

Introduction

Many plant species have been either accidentally or deliberately translocated far from their native areas (Khuroo et al 2007). Newly introduced plants, called alien plants (Pysek et al 2004), have various effects on the environment and economy of non-native areas. Some alien species, often cultivated, may provide food, medicine, fuel, or fodder to local communities (Kull et al 2007; Roder et al 2007). Other alien species have negative impacts on agricultural production, forest regeneration, livestock grazing, native vegetation, and ecosystems or human health (Pimentel et al 2000; Sharma et al 2005; Kohli et al 2006). Introduced species with high reproductive rates and the potential to spread rapidly over large areas are regarded as invasive alien plants (Pysek et al 2004).

The Himalayan region has also been invaded by alien plants (Khuroo et al 2007). The vegetation of Arunachal Himalaya is known for its great diversity and endemism (Behera et al 2002; Hegde 2003; Bhagabati et al 2006), and many plants are used for food, medicine, resin, fiber, handicrafts, or cultural rituals (Tag and Das 2004; Tag et al 2008). There have been few studies of invasive alien plants in this region, and information is required for management planning.

Arevalo et al (2005) and Pickering and Hill (2007) report that road construction facilitated plant invasion in mountainous regions and that the distribution pattern of invasive plants along roadsides varied with altitude. Arevalo et al (2005) found the highest number of alien plants at intermediate altitudes between 0 and 2000 m. Pauchard and Alaback (2004) showed that alien species richness was negatively correlated with elevation along roadsides between 280 and 1290 m. Similar patterns of invasion after road construction and distribution with altitude may also apply to the Arunachal Himalaya region.

The present study compiled information on the distribution patterns of some invasive alien plants alongside roads in Arunachal Himalaya and gathered information on cultural perceptions of invasive plants for development of plant resource management.

Material and methods

Study area

Arunachal Pradesh (26°28′–29°31′N; 91°30′–97°30′E) and Assam (24°09′–27°58′N; 89°42′–96°01′E) are located at the eastern end of the Himalayan region at altitudes between 100 and 7000 m. There are 3 seasons per year: a warm and dry summer (March–May), monsoon (June–September), and a cool and dry winter (October–February). About 85% of annual rainfall (3000 mm) occurs during the monsoon season. Mean annual maximum and minimum temperatures are 29.3°C and 19.2°C in Itanagar (200 m), 27°C and 16°C in Along (300 m), 22°C and 12°C in Ziro (1600 m), and 19°C and 5°C in Tawang (3000 m), respectively (Purkayastha 2008).

Vegetation types vary with altitude and climatic conditions, from tropical (below 900 m), subtropical (900–1800 m), temperate (1800–3500 m) to subalpine and alpine (above 3500 m). Rice is cultivated below 2000 m on the plain and valley floor, whereas shifting cultivation is conducted on hillsides up to 2500 m. Livestock, such as yak, yak-cattle hybrids, and sheep, are bred by highlanders and pastured above 3000 m.

There has been regional trade between Tibet and Arunachal Himalaya for centuries (Choudhury 1981; Choudhury 1996). However, Arunachal Himalaya was called the “hidden land,” because access for outside visitors was difficult (Blackburn 2003). After independence in 1947, the Indian government began a development program to construct roads, increase agricultural production, and improve public health (Elwin 1959). Nowadays, tourism is a significant economic activity, and many domestic and foreign tourists visit the region.

Material and methods

A total of 38 roadside plots at 5–30 km intervals were selected (Figure 1) along the Assam national highway (75–250 m) and a state major road in Arunachal Pradesh (200– 4200 m). Twenty-eight plots were in the tropical zone, 6 in subtropical, 3 in temperate, and 1 in subalpine and alpine zones. Strip-shaped plots alongside and parallel to the roads were sampled. Plot sizes varied from 50 m × 5 m to 200 m × 10 m because of variable land use, topography, and roadside vegetation. Between 2 and 5 replicates of a 50-m transect were sampled on each plot.

FIGURE 1

Map of 38 roadside plots in Arunachal Himalaya. (Map by Y. Kosaka)

i0276-4741-30-3-252-f01.tif

The abundance of alien species was recorded on a qualitative scale (Pauchard and Alaback 2004): A, abundant (present in >25% of the transect length); C, common (10–25%); I, intermittent (< 10%); and R, rare when only 1 group of individuals was present. Species abundance was determined by the maximum value recorded along the transects within the plot. A subjective percentage cover value was assigned to each of the qualitative abundance classes (Pauchard and Alaback 2004): A  =  50, C  =  25, I  =  10 and R  =  1. The location and altitude of the plots were recorded by global positioning system (GPS; Garmin GPSmap 60Cx).

Additional habitats of invasive alien plants were recorded (arable field, grassland, settlement area, water body) through direct observation and field interviews. In North Lakhimpur, Along, and Ziro, 3–5 knowledgeable local residents were asked when they first detected invasive alien plants, the habitat in which they were detected, the mode of introduction, harmful effects, and beneficial uses. A literature survey of known harmful effects or beneficial uses was completed for each plant identified. Data on species of Cyperaceae and Poaceae were not collected, because many individuals of these species were not in flower during the survey period, and accurate identification requires inflorescence.

Relative abundance and frequency were calculated for recorded species, and data were analyzed by detrended correspondence analysis (DCA) (Hill and Gauch 1980). Species compositional gradients among the plots were detected by PC-ORD version 5. The ordination matrix contained 37 plots (1 plot lacked alien species) and 18 species. Species with frequencies of ≤5% were excluded from analysis because minor species may cause unnecessary noise. The correlation between plot score in DCA axis 1 and elevation was tested by linear regression.

Alien plant species were determined as those not native to the eastern Himalayan region. The nomenclature, origin, growth form (Khuroo et al 2007), mode of reproduction, and mode of dispersal were recorded by following Harada et al (1993), Takematsu and Ichizen (1987, 1993, 1997), and Weber (2003).

Results

Characteristics of invasive alien plants in Arunachal Himalaya

A total of 18 invasive alien plants (frequency >5%) were recorded on 38 plots (Table 1). The dominant family was Asteraceae (9 species) followed by Fabaceae (3) and Verbenaceae (2). Most species originated in South America (13); others originated in North America (2), Europe (2), and Africa (1). Nine species also grew in arable fields, 3 in grassland, 3 in settlement areas, and 2 in water bodies. Ten species only reproduced by seed, 1 species by vegetative reproduction, and 7 species by both seed and vegetative reproduction. Aside from direct or indirect anthropogenic intervention, common dispersal modes included anemochory, endozoochory, and ombrohydrochory. Bidens pilosa also depends on epizoochory and Ipomoea carnea and Eichhornia crassipes are dispersed by hydrochory. Although most species were unintentionally introduced into this region, 4 species were intentionally introduced for beneficial uses (Table 2).

TABLE 1

Summary of the invasive alien plants in Arunachal Himalaya. (Table extended on next page.)

i0276-4741-30-3-252-t01.gif

TABLE 2

Harmful effects and beneficial uses of invasive alien plants recorded in Arunachal Himalaya and other regions.a)

i0276-4741-30-3-252-t02.gif

Species composition by altitude

The 37 plots were arranged along DCA axis 1 (eigen value [EIG]  =  0.85) in order of altitude (R  =  0.92, P < .001), whereas DCA axis 2 (EIG  =  0.36) was slightly related to record location, Arunachal or Assam (Figure 2).

FIGURE 2

DCA diagram of plots classified by altitude and location in Arunachal Himalaya. Five areas in 4 altitude zones correspond with vegetation zones.

i0276-4741-30-3-252-f02.tif

The number of species per plot varied from 2 to 8 in the tropical zone, from 3 to 8 in the subtropical zone, from 3 to 6 in the temperate zone, and only 1 species in the subalpine zone (Figure 3). The number of species per plot had no significant correlation with altitude (R  =  0.36) (Figure 3).

FIGURE 3

Number of species per plot at different altitudes in Arunachal Himalaya.

i0276-4741-30-3-252-f03.tif

The highest number of species (13) grew in the tropical zone, followed by the subtropical (10), temperate (6), and subalpine zones (1) (Figure 4). Parthenium hysterophorus, Ipomoea carnea, Crotalaria pallida, Mimosa pudica, Cuphea carthagenensis, and Stachytarpheta dichotoma grew only in the tropical zone. Ageratum conyzoides, Ambrosia artemisiifolia, Bidens pilosa, and Solanum carolinense grew in the widest range of habitats, from tropical to temperate zones. Except for these 4, species growing in the subtropical zone were recorded up to 1600 m, whereas species found in the temperate zone occurred above 1600 m. Few temperate zone species grew above 3000 m. Only 1 species, Taraxacum officinale, was recorded on the mountain pass at 4200 m, the highest plot in the present study (Figure 4).

FIGURE 4

Altitudinal range of invasive alien plants found in Arunachal Himalaya.

i0276-4741-30-3-252-f04.tif

Harmful effects and beneficial uses of invasive alien plants

Among 18 alien plants recorded, harmful effects were identified on crop production (14 species), livestock grazing (7), human health (4), water drainage (2), forest regeneration (1), and native vegetation (1), whereas beneficial uses were recorded as medicine (12), vegetable (4), fodder (2), hedge plant (2), fish growth (1), fallow plant (1), fish poison (1), manure (1), soil protection from erosion (1), and ornament (1).

Discussion

Distribution patterns of invasive alien plants

Most (83.3%) of the invasive alien plants in the Arunachal Himalaya region originated in North and South America (Table 1). A. conyzoides, B. pilosa, Galinsoga quadriradiata, and P. hysterophorus have been reported from Nepal (Manandhar 2002) and Kashmir Himalaya (Khuroo et al 2007), and these species may be spreading in the Himalayan region.

Although species composition changed with the altitudinal gradient (Figure 2), the number of species per plot was not related to altitude (Figure 3). The altitudinal range of species (Figure 4) corresponded with known biogeographical affinities and environmental tolerances. Temperate species were limited to highlands (above 1600 m), whereas 10 species of tropical origin (62.5%) were limited to lowlands (below 1600 m). Apart from T. officinale, alien species were not recorded above 3000 m where the temperature dropped to below the freezing point in the winter (Figure 4). Low temperature and snowfall in the highlands may filter nonadapted species from tropical regions (Pauchard and Alaback 2004; Arevalo et al 2005).

Plant invasions are influenced by climate; Ageratina adenophora, Chromolaena odorata, Mikania micrantha, E. crassipes, and Lantana camara were regarded as invasive in tropical Asia but not in temperate Asia (Weber 2003).

Plant invasion through recent road construction

Some alien plants were introduced into Himalayan regions by historical trading (Khuroo et al 2007), but Pickering and Hill (2007) suggest that recent road construction and road use facilitate the establishment of invasive alien plants in mountain regions. This view was supported by the recollections of elderly residents at the study sites. In Along (270 m), residents reported that S. carolinense was found after a road was built to Assam before 1990. M. micrantha and S. dichotoma have expanded their range since 2000. In Ziro (1600 m), A. artemisiifolia and S. carolinense spread after the road was connected from Assam in the 1950s. The spread of S. carolinense was related to the introduction of cattle from Assam that disseminated its seed. E. crassipes was introduced in 1970s, followed by G. quadriradiata after 2000.

Unintentionally introduced alien plants may subsequently disseminate seed or vegetative propagates by wind, water, or animals (Table 1). Burning in shifting cultivation also promotes the establishment of A. adenophora and C. odorata (Tripathi and Yadav 1987), as well as M. micrantha (Swamy and Ramakrishnan 1987).

Perception of local residents

Local informants reported harmful effects of invasive alien plants (Table 2). I. carnea impedes drainage and E. crassipes prostrates rice plants when plants drift onto wet fields during seasonal floods in North Lakhimpur. M. micrantha and S. dichotoma were reported to damage agricultural production by overhanging crops in Along. The spines on S. carolinense disturbed agriculture in Yazali. A. conyzoides and G. quadriradiata were regarded as major weeds, and downy fruits of A. adenophora and C. odorata were reported to cause breathing problems in Dirang.

Beneficial uses of invasive alien plants were also reported (Table 2). The leaf of A. conyzoides was squeezed and applied to wounds as styptic. E. crassipes was introduced to improve fish growth in aquaculture in Ziro. The young leaf of G. quadriradiata was eaten as a vegetable, and the fruit of S. carolinense was used as medicine against toothache in Dirang.

Conclusion

A total of 18 invasive alien plants, mostly from North and South America, were recorded from the Arunachal Himalaya area. Most species grew in the tropical zone, followed by the subtropical, temperate, and subalpine zones. Low temperature and snowfall in the highlands may filter nonadapted species from tropical regions. Data from a survey of residents and prior studies suggest that recent construction and use of roads facilitate the establishment of invasive alien plants. Although residents identified harmful effects of some alien plants, other plants were used as beneficial resources. The views of local residents and the benefits to subsistence livelihoods should be incorporated into ecosystem management planning.

Open access article: please credit the authors and the full source.

Acknowledgments

This study was conducted under the Memorandum of Understanding between Rajiv Gandhi University, Arunachal Pradesh, India, and the Research Institute for Humanity and Nature (RIHN), Japan, and supported by the RIHN project Human life, aging and disease in high-altitude environments (Leader: Dr. Kiyohito Okumiya, RIHN), the Ashoka Trust for Research in Ecology and the Environment, and the Critical Ecosystem Partnership Fund, India. We thank Prof Makoto Kato and Dr Shinya Takeda, Kyoto University, and Mr Tsering Wange, Mr Passang Tsering, Mr C. K. Ray, Mr Hage Komo, and many other people in Arunachal Pradesh and Assam for supporting the field study.

REFERENCES

  1. J. R. Arevalo, J. D. Delgado, R. Otto, A. Naranjo, M. Salas, and J. M. Fernandez-Palacios . 2005. Distribution of alien vs. native plant species in roadside communities along an altitudinal gradient in Tenerife and Gran Canaria (Canary Islands). Perspectives in Plant Ecology, Evolution and Systematics 7:185–202. Google Scholar

  2. M. D. Behera, S. P. S. Kushwaha, and P. S. Roy . 2002. High plant endemism in an Indian hotspot—eastern Himalaya. Biodiversity and Conservation 11:669–682. Google Scholar

  3. A. K. Bhagabati, M. C. Kalita, and S. Baruah . 2006. Biodiversity of Assam: Status Strategy and Action Plan for Conservation. Guwahati, India: EBH Publishers. Google Scholar

  4. S. Blackburn 2003. Colonial contact in the ‘hidden land’: Oral history among the Apatanis of Arunachal Pradesh. The Indian Economic and Social History Review 40:335–365. Google Scholar

  5. S. D. Choudhury editor. 1981. Arunachal Pradesh District Gazetteers—Subansiri District. Itanagar, India: Government of Arunachal Pradesh. Google Scholar

  6. S. D. Choudhury editor. 1996. Arunachal Pradesh District Gazetteers—East Kameng, West Kameng and Tawang District. Itanagar, India: Government of Arunachal Pradesh. Google Scholar

  7. V. Elwin 1959. A Philosophy for NEFA. Itanagar, India: Himalayan Publication. Google Scholar

  8. J. Harada, H. Shibayama, and H. Morita . 1993. Weeds in the Tropics [in Japanese]. Tokyo, Japan: AICAF [Association for International Cooperation of Agriculture & Forestry]. Google Scholar

  9. S. N. Hegde editor. 2003. Arunachal Pradesh State Biodiversity Strategy and Action Plan. Itanagar, India: Himalayan Publishers. Google Scholar

  10. M. O. Hill and H. G. Gauch . 1980. Detrended correspondence analysis: An improved ordination technique. Vegetatio 42:47–58. Google Scholar

  11. A. A. Khuroo, I. Rashid, Z. Reshi, G. H. Dar, and B. A. Wafai . 2007. The alien flora of Kashmir Himalaya. Biological Invasions 9:269–292. Google Scholar

  12. R. K. Kohli, D. R. Batish, H. P. Singh, and K. S. Dogra . 2006. Status, invasiveness and environmental threats of three tropical American invasive weeds (Parthenium hysterophorus L., Ageratum conyzoides L., Lantana camara L.) in India. Biological Invasions 8:1501–1510. Google Scholar

  13. C. A. Kull, J. Tassin, and H. Rangan . 2007. Multifunctional, scrubby, and invasive forests?: Wattles in the highlands of Madagascar. Mountain Research and Development 27:224–231. Google Scholar

  14. A. Love, S. Babu, and C. R. Babu . 2009. Management of Lantana, an invasive alien weed, in forest ecosystems of India. Current Science 97:1421–1429. Google Scholar

  15. N. P. Manandhar 2002. Plants and People of Nepal. Portland, OR: Timber Press. Google Scholar

  16. A. Pauchard and P. B. Alaback . 2004. Influence of elevation, land use, and landscape context on patterns of alien plant invasions along roadsides in protected areas of south-central Chile. Conservation Biology 18:238–248. Google Scholar

  17. C. Pickering and W. Hill . 2007. Roadside weeds of the snowy mountains, Australia. Mountain Research and Development 27:359–367. Google Scholar

  18. D. Pimentel, L. Lach, R. Zuniga, and D. Morrison . 2000. Environmental and economic costs of nonindigenous species in the United States. BioScience 50:53–65. Google Scholar

  19. A. K. Purkayastha 2008. Arunachal Agriculture Over the Years. Ulubari, India: P. R. Publishers and Printers. Google Scholar

  20. P. Pysek, D. M. Richardson, M. Rejmanek, G. L. Webster, M. Williamson, and J. Kirschner . 2004. Alien plants in checklists and floras: Towards better communication between taxonomists and ecologists. Taxon 53:131–143. Google Scholar

  21. P. S. Ramakrishnan and B. K. Mishra . 1981. Population dynamics of Eupatorium adenophorum Spreng. during secondary succession after slash and burn agriculture (jhum) in north eastern India. Weed Research 22:77–84. Google Scholar

  22. W. Roder, K. Dorji, and K. Wangdi . 2007. Implications of white clover introduction in East Himalayan grasslands. Mountain Research and Development 27:268–273. Google Scholar

  23. W. Roder, S. Phengchanh, B. Keoboualapha, and S. Maniphone . 1995. Chromolaena odorata in slash-and-burn rice systems of northern Laos. Agroforestry Systems 31:79–92. Google Scholar

  24. G. P. Sharma, J. S. Singh, and A. S. Raghubanshi . 2005. Plant invasions: Emerging trends and future implications. Current Science 88:726–734. Google Scholar

  25. S. N. Sharma 2001. The Herbal Flora of Assam and North-eastern India. Guwahati, India: Spectrum Publications. Google Scholar

  26. P. S. Swamy and P. S. Ramakrishnan . 1987. Effect of fire on population dynamics of Mikania micrantha H.B.K. during early succession after slash-and-burn agriculture (jhum) in northeastern India. Weed Research 27:397–403. Google Scholar

  27. H. Tag and A. K. Das . 2004. Ethnobotanical notes on the Hill Miri tribe of Arunachal Pradesh. Indian Journal of Traditional Knowledge 3:80–85. Google Scholar

  28. H. Tag, G. Murtem, A. K. Das, and R. K. Singh . 2008. Diversity and distribution of ethnomedicinal plants used by the Adi Tribe in East Siang District of Arunachal Pradesh, India. Pleione 2:123–136. Google Scholar

  29. T. Takematsu and N. Ichizen . 1987. Weeds of the World, Volume 1 [in Japanese]. Tokyo, Japan: Zenkoku Noson Kyoiku Kyokai. Google Scholar

  30. T. Takematsu and N. Ichizen . 1993. Weeds of the World, Volume 2 [in Japanese]. Tokyo, Japan: Zenkoku Noson Kyoiku Kyokai. Google Scholar

  31. T. Takematsu and N. Ichizen . 1997. Weeds of the World, Volume 3 [in Japanese]. Tokyo, Japan: Zenkoku Noson Kyoiku Kyokai. Google Scholar

  32. Y. Toukura, N. Yamamoto, and A. Hongo . 2008. Plant utilization of Sherpa people—The case of Pangkarma Village in Nepal [in Japanese]. Himalayan Study Monographs 9:10–16. Google Scholar

  33. R. S. Tripathi and A. S. Yadav . 1987. Population dynamics of Eupatorium adenophorum Spreng. and Eupatorium riparium Regel in relation to burning. Weed Research 27:229–236. Google Scholar

  34. E. Weber 2003. Invasive Plant Species of the World: A Reference Guide to Environmental Weeds. Oxfordshire, United Kingdom: CABI Publishing. Google Scholar

Yasuyuki Kosaka, Bhaskar Saikia, Tasong Mingki, Hui Tag, Tomo Riba, and Kazuo Ando "Roadside Distribution Patterns of Invasive Alien Plants Along an Altitudinal Gradient in Arunachal Himalaya, India," Mountain Research and Development 30(3), (1 August 2010). https://doi.org/10.1659/MRD-JOURNAL-D-10-00036.1
Received: 1 May 2010; Accepted: 1 June 2010; Published: 1 August 2010
JOURNAL ARTICLE
7 PAGES


SHARE
ARTICLE IMPACT
Back to Top