Results

Plant diversity and abundance

Farms in theTerai are rich in biodiversity that provide essential goods that sustain livelihoods and, correspondingly, land managers maintain a rich ethnobotanical knowledge. Overall, 390 vascular plant specimens were collected and identified as belonging to 76 distinct plant species from 49 phylogenetic families. Individual farms have in between 1 and 27 useful plants (i.e., important and

Table 18.1 Comparison across climatic regions of plant species diversity (H j, abundance, and relative constitution of number of plant species, according to use categories

Note:

Table 18.1 presents (a) diversity, (b) abundance, and (c) the results of our analysis of the relative constitution of number of plant species, according to use categories. Values show the mean + SE. Unique plant species were found in each climatic region, and the highest number of unique species was found in Kupandehi. Unique species refers to species found only in one climatic region, (sp.: species).

commonly used). In the entire study area, species diversity (H’) is 3.09+0.09 (mean+SE), species abundance is 9.75+0.74 and the average number of plants/farm is 9.75+4.71 (Table 18.1). Of the 76 plant species collected, 56 are used for medicine, 27 for rituals, 25 for food, 20 for timber, 17 for fuel, 17 for fodder, 11 for soil enhancement, and 8 for pesticides. Most plants (73.3 per cent) are used for multiple purposes: 29.3 per cent are used for two, 22.7 per cent for three, 12 per cent for four, 6.7 per cent for five, and 2.7 per cent for six purposes. Eight species are considered to have disservices (e.g. invasive weeds). The most dominant plant families are Euphorbiaceae (5 families), Fabaceae (4), Moraceae (4), Anacardiaceae, Lamiaceae, and Rutaceae (3).The most common species are Shorea robusta (Sal tree) (6.7 per cent), Dalbcrgia sisoo (Indian rosewood) (6.4 per cent), Azadirachta indica (Mugwort) (6.4 per cent), Melia azedarach (Persian lilac) (5.1 per cent), Leucaena leucocephala (Leucaena) (4.4 per cent), Ficus religiosa (Banaya tree) (4.4 per cent), Dendrocalamus strictus (Bamboo) (4.4 per cent), Ocimum tenuiflorum (Holy basil) (4.4 per cent), Mangifera indica (Mango) (3.9 per cent), and Jatropha curcas (Physic nut) (3.1 per cent) (Storrs and Storrs 1998; Singh, Kumar, and Twearu 2012; IUCN 2004). (See Thorn et al. 2020 for full details of all the species identified.)

Source of biological material

Biological material is collected from farm boundaries, around homesteads, home gardens, or uncultivated patches, such as wetlands, small woodlands or riverbanks. Farmed areas are typically adjacent to homesteads, around which smallholders maintain wind and shade barriers, nurseries, fruit orchards, ornamentals, spices, vegetables, zero-grazing pens for raising domestic animals, and multi-storied crops (e.g. grasses, herbs, shrubs, trees) (Figure 18.2). Contour hedgerows

Figure 18.2 Adapted schematic view illustrating a typical multi-layered system of trees, herbs, climbers, grasses and herbs, in a heterogeneous, integrated cropping system in theTerai: (a) road, (b) pathway, (c) rice paddy fields (d) lentil and soya bean grown along boundaries, (e) tube wells, or slurry processing for biogas, (f) vegetable garden (e.g. bottle gourd, cucumber, tomato, beans, okra, sesame), spices (e.g. ginger, turmeric) and cosmetics (e.g. aloe vera) with mulched patches and ridges/bunds for water efficiency, (g) buffalo, goat or pig pen and fuel wood storage, (h) cluster of trees alongside boundary for windbreaks (e.g. Dendroclamus strictus), fuel wood and timber (e.g. Dalbergia sisoo, Shorea robusta, Melia azedarach), fruit (e.g. Psidium guajada), fodder (e.g. Azadirachta indica, Albizia lebbeck), religious value (e.g. Aeglc marínelos), or shade (e.g. Mangifera indica), (i) house roof made of reed thatch, covered with creepers and gourds for aesthetic value, insulation, and food

along terrace ridges (e.g. lentils, soya bean) are more common than intercropped hedgerows — and are used to mitigate soil erosion on moderately sloping land, conserve soil nutrients and limit competition with crops for water and sunlight (Haenke et al. 2014). Fuel wood is typically sourced from trees around homes (in 41 per cent of cases), from community forests and national parks (71 per cent) or bought from traders (19.4 per cent). In 25 per cent of cases, fuel wood comes from two or three sources, but in some cases material cultivated around homes is sufficient.

Processing and administration

Of the 76 species recorded in the study area, the most commonly used growth forms are trees (51 per cent of species), herbs (24 per cent) and shrubs (16 per cent). Ten parts of the plant are used — most commonly the leaf (23 per cent), fruit or stem (14 per cent), flower (10 per cent) or bark (9 per cent). Other parts used are the root, flower, bark, seed, latex, shoot, and resin but rarely the entire plant (3 per cent). Generally, fresh plant parts are collected and used immediately. Alternatively, plants are stored in the shade or dry places in their original form, powdered or used as an ash. Plants are consumed directly, roasted, juiced or pickled, or applied externally using the paste of leaves or milky latex. Administration of most medicinal plants is viadecoction (mashing, and boiling the plant in water to extract oils, volatile organic compounds, and other chemical substances), although dermatological ailments are usually treated topically. For example the leaves of Azadirachta indica (Margosa tree) are used to wash the skin to treat scabies (Storrs and Storrs 1998; IUCN 2004; Singh et al. 2012).

Administration of biological material varies across seasons. For example Asparagus racemosus (Asparagus) is used to prepare alcohol in August, and the fruit of Paris polyphylla (Herb paris) is used for worship in mid-April. Although most Community Forestry User Groups officially restrict the harvest of fuel wood between December—February and during festivals in November (e.g. Daishan, Tihar), in 48 per cent of cases, fuel wood is collected throughout the year. Administration of biological material furthermore varies according to the day of the week. For example on Tuesdays and Thursdays, women practise a ritual which involves grinding and eating the root of Mimosa pudica (Touch-me-not plant), or chewing the stem of Calotropis gigantea (Crown flower), to promote the well-being of their husbands. Other species are regularly ingested, such as Aegle marmelos (Bengal quince), the leaves and fruit pulp used as an offering to Lord Shiva (IUCN 2004; Madhu, Phoboo, and [ha 2010; Singh et al. 2012; Government of Nepal 2014).