Agroforestry Services: Crop shade  Agroforestry Services: Nitrogen  Fodder: Bank  Industrial Crop: Biomass  Industrial Crop: Pesticide  Management: Coppice  Management: Standard  Minor Global Crop

Although siris will grow in the humid tropics, its natural range is in semi-arid to sub-humid areas of the tropics and subtropics that have marked dry and reliable wet seasons[ 310 , 404 ]. However, it may be established under conditions of low (400 mm/year) and irregular rainfall[ 310 ]. Plants can succeed at elevations from sea level to 1,800 metres in areas where annual daytime temperatures are within the range 26 - 36c, but can tolerate 12 - 48c[ 303 , 418 ]. It prefers a mean annual rainfall in the range 600 - 2,000mm, but tolerates 500 - 2,500mm[ 303 , 418 ]. Seedlings will not tolerate frost, but trees are moderately frost resistant when established[ 418 ]. Prefers a well-drained, moisture-retentive soil and a position in full sun[ 200 ]. Plants are able to succeed in most soil types, including saline but excluding cracking clay, so long as they are well drained[ 307 ]. Tolerant of degraded or nutritionally poor soils[ 307 ]. Prefers a pH in the range 6 - 7, tolerating 5.5 - 8.5[ 418 ]. Established plants are very drought tolerant[ 307 ]. Seedlings will not tolerate waterlogging[ 310 ]. Requires a position sheltered from strong winds[ 303 ]. Widely cultivated, the tree has become established in the wild in various areas outside its native range and is considered to be invasive in some of these areas[ 305 ]. A fast-growing species, it can reach a height of 18 metres within 10 years from seed[ 418 ]. When grown as a fuel crop on a coppice rotation of 10 - 15 years, it can produce about 5 cubic metres per hectare[ 418 ]. Optimum annual wood production is 15 - 20 cubic metres per hectare[ 418 ]. Plants have brittle limbs that can break off in high winds[ 307 ]. They also have a shallow, though wide-spreading root system that does not support them well in windy positions[ 307 ]. The dried seedpods hanging on the tree constantly rattle in the wind[ 362 ]. Reserves in the root system enable young plants to survive total defoliation from fire or grazing, but with an obvious setback in growth[ 310 ]. The tree coppices well, responds to pollarding, pruning and lopping, and will produce root suckers if the roots are exposed[ 303 ] The trees are killed by even light fires[ 303 ]. This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[ 200 ]. The tree is not Rhizobium specific, and native strains are nearly always capable of producing an abundance of nodules[ 303 ].

Carbon Farming

• Agroforestry Services: Crop shade  Plants providing crop shade especially trees.
• Agroforestry Services: Nitrogen  Plants that contribute to nitrogen fixation include the legume family – Fabaceae.
• Fodder: Bank  Fodder banks are plantings of high-quality fodder species. Their goal is to maintain healthy productive animals. They can be utilized all year, but are designed to bridge the forage scarcity of annual dry seasons. Fodder bank plants are usually trees or shrubs, and often legumes. The relatively deep roots of these woody perennials allow them to reach soil nutrients and moisture not available to grasses and herbaceous plants.
• Industrial Crop: Biomass  Three broad categories: bamboos, resprouting woody plants, and giant grasses. uses include: protein, materials (paper, building materials, fibers, biochar etc.), chemicals (biobased chemicals), energy - biofuels
• Industrial Crop: Pesticide  Many plants provide natural pesticides.
• Management: Coppice  Cut to the ground repeatedly - resprouting vigorously. Non-destructive management systems maintaining the soil organic carbon.
• Management: Standard  Plants grow to their standard height. Harvest fruit, seeds, or other products. Non-Destructive management systems.
• Minor Global Crop  These crops are already grown or traded around the world, but on a smaller scale than the global perennial staple and industrial crops, The annual value of a minor global crop is under $1 billion US. Examples include shea, carob, Brazil nuts and fibers such as ramie and sisal.