Swietenia macrophylla King. (big-leaf mahogany)

The basics	Big-leaf mahogany, the main source of mahogany timber, is one of “a very small group of tropical, fast-growing, light-demanding trees with high-value timber” [1]. Native to the neotropics, it is cultivated pantropically. It is suitable for many agroforestry uses.
Climatic requirements	Lowland tropics (wet and seasonally dry).
Most salient traits and their +ve implications	Attractive (reddish, golden-sheened, decorative grain), relatively light, easily worked, durable, and stable heartwood; large size (therefore historically available in large dimensions) ⟹ long-established high demand in furniture-making and high-quality interior construction [2]. Fast early growth; light-loving; high-value timber ⟹ use in monospecific plantations and agroforestry combinations [3] Deep tap root even in seedlings [4]; deciduous ⟹ drought tolerance [5]. Long-lived pioneer; fast early growth; abundant seeding and natural regeneration; seedlings tolerant of long periods of shade ⟹ useful in forest restoration. “Gap species” ⟹ suitable for enrichment planting.
Most salient traits and their -ve implications	High-value wood (see above) and low density in natural forest ⟹ overexploitation ⟹ extinction or scarcity in some parts of its range (CITES listed). Heavily attacked (“crippling susceptibility” [1]) by the shoot-boring larvae of the moth Hypsipyla grandella ⟹ risk of plantation abandonment and failure (around 100% of trees in conventional open-grown plantations attacked in first two years [12]).
Problem mitigation	The larvae of Hypsipyla moths bore and kill young, non-woody shoots. Following attack, vertical growth ceases for a period of weeks to months, after which growth resumes from one or, more usually, several previously dormant buds [12], leading to low forking of the crown. Planting under partial shade and low density in agroforestry combinations may reduce attack rates [15](possible mechanisms: moths deposit far fewer eggs on shaded tissues [7], higher production of specific volatile organic compounds [8], physical barrier). However, larvae seem to feed more aggressively on shaded tissues [7]; even one feeding larva can destroy a growing shoot. Further, vigorous growth is needed to recover adequately from attack; that is, to lay down new lignified tissue before renewed attack. Moderate lateral shade, e.g. from cacao or coffee, coupled with (a) overhead light to maintain vigour and (b) targeted pruning to correct forking, interrupt ongoing attack, and facilitate rapid regrowth [13, 14] are probably the best combination of measures.
Other must-knows	Mahogany seed is orthodox – that is, after drying to moisture content <5% it can be stored for long periods at low temperature, including subzero temperatures [3, 9]. Can grow on acidic sites, particularly if limed [10] but has preference for neutral to alkaline soils. Ca be harvested as young as 20–25 years, but financially optimum rotation rates more likely to be in the 40–60 year range [11]. In a 59-year-old plantation in Puerto Rico, heartwood comprised 67–82 of volume under bark [15]. Big-leaf mahogany is also known as Honduras mahogany.
References	[1] Whitmore TC. 2003. Mahogany: tree of the future. Pp. 1–6 in Lugo et al (eds.), Big-leaf mahogany: genetics, ecology, and management. Ecological Studies Vol. 159. Springer. [2] Dahms K-G. 1989. Das Holzportrait Echtes oder amerikanisches Mahagoni. Holz als Roh- und Werkstoff 47: 1–6. [3] Mayhew JE Newton AC. 1998. The silviculture of mahogany. CABI Publishing. [4] Gerhardt K, Fredricksson D. 1995. Biomass allocation by broad-leaf mahogany seedlings (Swietenia macrophylla (King), in abandoned pasture and secondary dry forest in Guanacaste, Costa Rica. Biotropica 27(2): 174–182. [5] Cordeiro YEM et al. 2009. Physiological and morphological responses of young mahogany (Swietenia macrophylla King) plants to drought. Forest Ecology and Management 258 (2009) 1449–1455. [6] Lamb FB. 1966. Mahogany of tropical America. Ann Arbor. [7] Mahroof R et al. 2002. Effects of artificial shade on attack by the mahogany shoot borer, Hypsipyla robusta (Moore). Agricultural and Forest Entomology 4(4): 283–292. [8] Borges R et al. 2022. Why shading cedar (Cedrela fissilis) reduces damage caused by mahogany shoot borer, Hypsipyla grandella (Zeller)? Forest Ecology and Management 504 (2022) 119853. [9] Chien CT et al. 2009. Bigleaf mahogany (Swietenia macrophylla King) seeds in Taiwan exhibit orthodox storage behaviour. Seed Science and Technology 37(2), pp. 503-506. [10] da Silva Jr. ML et al. 2018. Growth of young Brazilian mahogany (Swietenia macrophylla King) plants under different doses of calcium. Australian Journal of Crop Science 12(9): 1393-1397. [11] Forero-Montaña J et al. 2021. Developing a growth and yield model for planted big-leaf mahogany (Swietenia macrophylla King) at advanced age in subtropical moist forest in Puerto Rico. Trees, Forests and People 5 (2021) 100113. [12] Cornelius JP. 2009. The utility of the predictive decapitation test as a tool for early genetic selection for Hypsipyla tolerance in big-leaf mahogany (Swietenia macrophylla King). Forest Ecology and Management 257(8): 1815-1821. [13] Cornelius JP. 2001. The effectiveness of pruning in mitigating Hypsipyla grandella attack on young mahogany (Swietenia macrophylla King) trees. Forest Ecology and Management 148 (1–3): 287–289. [14] Cornelius JP and Watt AD. 2003. Genetic variation in a Hypsipyla-attacked clonal trial of Cedrela odorata under two pruning regimes. Forest Ecology and Management 183 (2003): 341–349. [15] Wadsworth, FH et al. 2003. Fifty-nine-year performance of planted big-leaf mahogany (Swietenia macrophylla King.) in Puerto Rico. Pp. 342–361 in Lugo et al (eds.), Big-leaf mahogany: genetics, ecology, and management. Ecological Studies Vol. 159. Springer.