Roadside Distribution Patterns of Invasive Alien Plants Along an Altitudinal Gradient in Arunachal Himalaya, India Author(s): Yasuyuki Kosaka, Bhaskar Saikia, Tasong Mingki, Hui Tag, Tomo Riba, and Kazuo Ando Source: Mountain Research and Development, 30(3):252-258. 2010. Published By: International Mountain Society DOI: 10.1659/MRD-JOURNAL-D-10-00036.1 URL: http://www.bioone.org/doi/full/10.1659/MRD-JOURNAL-D-10-00036.1 BioOne (www.bioone.org) is an electronic aggregator of bioscience research content, and the online home to over 160 journals and books published by not-for-profit societies, associations, museums, institutions, and presses. Your use of this PDF, the BioOne Web site, and all posted and associated content indicates your acceptance of BioOne’s Terms of Use, available at www.bioone.org/page/terms_of_use. Usage of BioOne content is strictly limited to personal, educational, and non-commercial use. 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Mountain Research and Development (MRD) MountainResearch An international, peer-reviewed open access journal Systems knowledge published by the International Mountain Society (IMS) www.mrd-journal.org Roadside Distribution Patterns of Invasive Alien Plants Along an Altitudinal Gradient in Arunachal Himalaya, India Yasuyuki Kosaka1*, Bhaskar Saikia2, Tasong Mingki2, Hui Tag2, Tomo Riba3, and Kazuo Ando4 * Corresponding author: [email protected] 1 Research Institute for Humanity and Nature; 457-4 Motoyama Kamigamo, Kita-ku, 603-8047, Kyoto, Japan 2 Department of Botany, Faculty of Life Sciences, Rajiv Gandhi University, Rono Hills, Itanagar, 791112, Arunachal Pradesh, India 3 Department of Geography, Faculty of Environmental Sciences, Rajiv Gandhi University, Rono Hills, Itanagar, 791112, Arunachal Pradesh, India 4 Center for Southeast Asian Studies, Kyoto University, 46 Yoshidashimoadachi-cho, Sakyo-ku, 606-8501, Kyoto, Japan Open access article: please credit the authors and the full source. Invasive plants have may filter nonadapted species from tropical regions and that spread all over the world, recent construction and use of roads facilitate the including the Himalayan establishment of invasive alien plants. Although several region. In 2009, the invasive alien plants were regarded as noxious weeds, local distribution pattern of residents in the study area mentioned their beneficial uses: A. invasive alien plants was conyzoides and Solanum carolinense are used as medicine, studied on 38 plots, from Galinsoga quadriradiata is used as a vegetable, and 100 to 4200 m, in Eichhornia crassipes is used to improve fish growth in Arunachal Pradesh and aquaculture. Information from scientific assessment and local Assam, India. Eighteen perception of invasive alien plants will assist in the invasive alien plants (frequency .5%) from 7 families were development of appropriate plant resource management recorded, of which 15 species (83.3%) were from North and plans in Arunachal Himalaya. South America. The most common plants by both frequency and coverage (.50%) were Ageratum conyzoides, Keywords: Altitudinal gradient; plant invasion; perception of Chromolaena odorata, and Mikania micrantha. Species local residents; plant resource management; road composition changed with altitude. Thirteen species grew in construction; Arunachal Pradesh; Assam; India. 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 Peer-reviewed: May 2010 Accepted: June 2010 Introduction many plants are used for food, medicine, resin, fiber, handicrafts, or cultural rituals (Tag and Das 2004; Tag et Many plant species have been either accidentally or al 2008). There have been few studies of invasive alien deliberately translocated far from their native areas plants in this region, and information is required for (Khuroo et al 2007). Newly introduced plants, called alien management planning. plants (Pyseket al 2004), have various effects on the Arevalo et al (2005) and Pickering and Hill (2007) environment and economy of non-native areas. Some report that road construction facilitated plant invasion in alien species, often cultivated, may provide food, mountainous regions and that the distribution pattern of medicine, fuel, or fodder to local communities (Kull et al invasive plants along roadsides varied with altitude. 2007; Roder et al 2007). Other alien species have negative Arevalo et al (2005) found the highest number of alien impacts on agricultural production, forest regeneration, plants at intermediate altitudes between 0 and 2000 m. livestockgrazing, native vegetation, and ecosystems or Pauchard and Alaback(2004) showed that alien species human health (Pimentel et al 2000; Sharma et al 2005; richness was negatively correlated with elevation along Kohli et al 2006). Introduced species with high roadsides between 280 and 1290 m. Similar patterns of reproductive rates and the potential to spread rapidly invasion after road construction and distribution with over large areas are regarded as invasive alien plants altitude may also apply to the Arunachal Himalaya region. (Pyseket al 2004). The present study compiled information on the The Himalayan region has also been invaded by alien distribution patterns of some invasive alien plants plants (Khuroo et al 2007). The vegetation of Arunachal alongside roads in Arunachal Himalaya and gathered Himalaya is known for its great diversity and endemism information on cultural perceptions of invasive plants for (Behera et al 2002; Hegde 2003; Bhagabati et al 2006), and development of plant resource management. Mountain Research and Development Vol 30 No 3 Aug 2010: 252–258252 http://dx.doi.org/10.1659/MRD-JOURNAL-D-10-00036.1 ß 2010 by the authors MountainResearch FIGURE 1 Map of 38 roadside plots in Arunachal Himalaya. (Map by Y. Kosaka) Material and methods 1947, the Indian government began a development program to construct roads, increase agricultural Study area production, and improve public health (Elwin 1959). Arunachal Pradesh (26u289–29u319N; 91u309–97u309E) and Nowadays, tourism is a significant economic activity, and Assam (24u099–27u589N; 89u429–96u019E) are located at many domestic and foreign tourists visit the region. the eastern end of the Himalayan region at altitudes Material and methods between 100 and 7000 m. There are 3 seasons per year: a A total of 38 roadside plots at 5–30 km intervals were warm and dry summer (March–May), monsoon (June– selected (Figure 1) along the Assam national highway (75– September), and a cool and dry winter (October– 250 m) and a state major road in Arunachal Pradesh (200– February). About 85% of annual rainfall (3000 mm) 4200 m). Twenty-eight plots were in the tropical zone, 6 in occurs during the monsoon season. Mean annual subtropical, 3 in temperate, and 1 in subalpine and alpine maximum and minimum temperatures are 29.3uC and zones. Strip-shaped plots alongside and parallel to the 19.2uC in Itanagar (200 m), 27uC and 16uC in Along roads were sampled. Plot sizes varied from 50 m 3 5mto (300 m), 22uC and 12uC in Ziro (1600 m), and 19uC and 200 m 3 10 m because of variable land use, topography, 5uC in Tawang (3000 m), respectively (Purkayastha 2008). and roadside vegetation. Between 2 and 5 replicates of a Vegetation types vary with altitude and climatic 50-m transect were sampled on each plot. conditions, from tropical (below 900 m), subtropical (900– The abundance of alien species was recorded on 1800 m), temperate (1800–3500 m) to subalpine and a qualitative scale (Pauchard and Alaback2004): alpine (above 3500 m). Rice is cultivated below 2000 m on A, abundant (present in .25% of the transect length); the plain and valley floor, whereas shifting cultivation is C, common (10–25%); I, intermittent (, 10%); and R, rare conducted on hillsides up to 2500 m. Livestock, such as when only 1 group of individuals was present. Species yak, yak-cattle hybrids, and sheep, are bred by highlanders abundance was determined by the maximum value and pastured above 3000 m. recorded along the transects within the plot. A subjective There has been regional trade between Tibet and percentage cover value was assigned to each of the Arunachal Himalaya for centuries (Choudhury 1981; qualitative abundance classes (Pauchard and Alaback Choudhury 1996). However, Arunachal Himalaya was 2004): A 5 50, C 5 25, I 5 10 and R 5 1. The location and called the ‘‘hidden land,’’ because access for outside visitors altitude of the plots were recorded by global positioning was difficult (Blackburn 2003). After independence in system (GPS; Garmin GPSmap 60Cx). Mountain Research and Development 253 http://dx.doi.org/10.1659/MRD-JOURNAL-D-10-00036.1 MountainResearch TABLE 1 Summary of the invasive alien plants in Arunachal Himalaya. (Table extended on next page.) Scientific name Family Origina) Frequency (%) Growth formb) Ageratum conyzoides L. Asteraceae AMS 58.0 Ah Ambrosia artemisiifolia L. Asteraceae AMN 7.9 Ah Bidens pilosa L. Asteraceae AMS 37.0 Ah Ageratina adenophora (Spreng.) King & H. E. Robins Asteraceae AMS 5.3 P/S Chromolaena odorata (L.) King & H. E. Robins Asteraceae AMS 68.4 P/S Galinsoga quadriradiata Ruiz & Pav. Asteraceae AMS 10.5 Ah Mikania micrantha Kunth Asteraceae AMS 55.3 C Parthenium hysterophorus L. Asteraceae AMS 7.9 Ah Taraxacum officinale (L.) Weber ex F. H. Wigg Asteraceae EU 10.5 P Ipomoea carnea Jacq. Convolvulaceae AMS 7.9 S Crotalaria pallida Aiton Fabaceae AF 13.1 Ah/P Mimosa pudica L. Fabaceae AMS 7.9 Ah/P Trifolium repens L. Fabaceae EU 5.3 P Cuphea carthagenensis (Jacq.) Macbr. Lythraceae AMS 15.8 Ah/P Eichhornia crassipes (Mart.) Solms Pontederiaceae AMS 18.4 Aq Solanum carolinense L. Solanaceae AMN 63.1 P Lantana camara L. Verbenaceae AMS 18.4 S Stachytarpheta dichotoma Vahl.