Constructing a database of alien plants in the Himalayas to test patterns structuring diversity

Rana, Suresh1 ; Dangwal, Bhawana1; Rawat, Gopal2; Price, Trevor3

Published Jul 23, 2024 on Dryad. https://doi.org/10.5061/dryad.k6djh9w8t

Data files

Jul 23, 2024 version files 208.45 KB

File-1.docx

29.40 KB
File-2.xlsx

161.30 KB
README.docx

12.68 KB
README.md

5.07 KB

Abstract

Differences in the number of alien plant species in different locations may reflect climatic and other controls that similarly affect native species and/or propagule pressure accompanied by delayed spread from the point of introduction. We set out to examine these alternatives for Himalayan plants, in a phylogenetic framework. We build a database of alien plant distributions for the Himalayas. Focusing on the well-documented regions of Jammu & Kashmir (west) and Bhutan (east) we compare alien and native species for (1) richness patterns, (2) the degree of phylogenetic clustering, (3) the extent to which species-poor regions are subsets of species-rich regions and (4) continental and climatic affinities/source. We document 1470 alien species (at least 600 naturalised), which comprise ~14% of the vascular plants known from the Himalayas. Alien plant species with tropical affinities decline in richness with elevation and species at high elevations form a subset of those at lower elevations, supporting location of introduction as an important driver of alien plant richness patterns. Separately, elevations that are especially rich in native plant species are also rich in alien plant species, suggesting an important role for climate (high productivity) in determining both native and alien richness. We find no support for the proposition that variance in human disturbance or numbers of native species correlate with alien distributions. Results imply an ongoing expansion of alien species from low-elevation sources, some of which are highly invasive.

README: Constructing a database of alien plants in the Himalayas to test patterns structuring diversity

Description of the dataset

The dataset contains two files.

File-1 (word file) contains a list of 31 regional floras and 93 research articles which were reviewed comprehensively for information on the distribution and elevational ranges of all alien plant species reported from the Himalayas.

File-2 (Excel file) contains details of all the alien species.

To harmonise taxonomy across sources, we assessed all species names against the updated list of botanical names available from www.worldfloraonline.org (World Flora Online) and resolved every taxon to species level. Any species whose native distribution extends into the Himalayan region is considered as a native, whereas a species whose native range is elsewhere is considered as alien. Native and alien distributional ranges of all species were validated from various online sources including the Invasive Species Compendium (www.cabi.org/isc), the Global Invasive Species Database (http://www.iucngisd.org/gisd/), and the USDA-GRIN (https://npgsweb.ars-grin.gov/). A complete dataset of alien species along with the hyperlinks to the sources are provided for each species in the file. Species were classified as cultivated (species that are cultivated by humans for food or ornaments) or naturalised (a species that does not require human assistance to reproduce and maintain itself in its natural environment). Note that many cultivated species may also be naturalised, but we prioritise cultivated over naturalised in this compilation. We also listed each species as invasive (species considered to have harmful impacts) as classified by the Global Invasive Species databases (hence not necessarily invasive in the Himalayas).

To assess source regions we recorded the native range of alien species to the continents (Africa, Australia, Europe, North America, and South America). Tropical Asia and Temperate Asia were not separated because the Himalayas act as a boundary between these two regions and species distributions have been assigned too crudely to classify them unambiguously. Plant species were also classified into three biogeographic categories, i.e., tropical, temperate, and cosmopolitan, based on the centre of species diversity within each genus. These data are unavailable for 525 species (<5%, 378 native species, 147 alien species) which we excluded from relevant analyses.

Description of the variables in the data

Synonyms: The columns contain names of species which are currently treated as synonyms of botanical names reported in the column Species. All species names reported in the published literature were checked for their latest taxonomic status at www.worldfloraonline.org (World Flora Online) and all synonyms were placed in a separate cell against the currently accepted names of the species.
Species: The column contains all currently accepted names of alien plant species reported in the published literature from the Himalayas. Blank cells mean no synonyms reported for the species in the Himalayas.
Authority: The column contains the author's name of the currently accepted botanical name of alien plant species in the Himalayas.
Family: Family of the species.
Genus: Genus of the species.
Life form: Life forms of the species include Trees, Shrubs, Herbs, Woody and herbaceous Climbers, Palms, and Bamboo.
Habit: This column includes the nature of the alien species including Naturalised, Invasive, Cultivated, and Unknown.
Affinity: This column includes the climatic affinity of the species such as Tropical, Temperate, Cosmopolitan, and Unknown.
Names of the continents: These columns show the native range of the alien species in the Himalayas. The 1 represents that the species is native to the continent and the black cell shows either the absence or non-native presence of the species in the continent.
Names of geographic regions in the Himalayas: These columns represent the presence of species within the sic geographic regions of the Himalayas, i.e., Arunachal Pradesh, Bhutan, Nepal, Uttarakhand, Himachal Pradesh, and Jammu and Kashmir. The 1 represents the presence of species in the geographic region whereas blank means the absence of species in the respective geographic region.
Lower Limit: Lowest elevation of the species in the Himalayas. Blank cell means elevational range not reported for the species in the Himalayas.
Upper Limit: Highest elevation of the species in the Himalayas. Blank cell means elevational range not reported for the species in the Himalayas.
Range: Range of elevational range of the species in the Himalayas in meters. Blank cell means elevational range not reported for the species in the Himalayas.
URL: The column contains hyperlinks to the original sources showing the distribution status of the species.
Common name: The column shows common names of the species in the Himalayas or elsewhere. Blanck cells mean common names are not available for the species.