Over‐harvesting driven by consumer demand leads to population decline: big‐leaf mahogany in South America

Abstract

Consumer demand for the premier neotropical luxury timber, big-leaf mahogany (Swietenia macrophylla), has driven boom-and-bust logging cycles for centuries, depleting local and regional supplies from Mexico to Bolivia. We revise the standard historic range map for mahogany in South America and estimate the extent to which commercial stocks have been depleted using satellite data, expert surveys, and sawmill processing center data from Brazil. We estimate an historic range of 278 million hectares spanning Venezuela to Bolivia, 57% of this in Brazil. Approximately 58 million hectares (21%) of mahogany's historic range had been lost to forest conversion by 2001. Commercial populations had been logged from at least 125 million more hectares, reducing the commercial range to 94 million hectares (34% of historic). Surviving stocks are extremely low-density populations in remote regions representing a smaller fraction of historic stocks than expected based on estimated current commercial range. Our method could advance international policy debates such as listing proposals for CITES Appendices by clarifying the commercial and conservation status of high-value timber species similar to mahogany about which little information is available. The fate of remaining mahogany stocks in South America will depend on transforming current forest management practices into sustainable production systems.

Island Invasion by a Threatened Tree Species: Evidence for Natural Enemy Release of Mahogany (Swietenia macrophylla) on Dominica, Lesser Antilles

“…Both of these Swietenia species are on the IUCN Red List. Where accessible, mahogany populations have been effectively ‘mined’ in their native forests, most of which have become fragmented and converted to agriculture and ranching after logging [20], [21], [31]. In spite of CITES protections — S. mahagoni was listed in 1992, and S. macrophylla added in 2003 — S. macrophylla is still widely harvested in an unsustainable manner [31], [36], while S. mahagoni has long been “commercially extinct” [19], [20], [24].…”

“…This case is compelling from a conservation and resource management perspective, in that the potential invader species ( Swietenia spp.) remains highly threatened in forests of their native range in spite of their international trade regulated under CITES Appendix II [24], [31]. Here, we address three main questions: (1) Do Swietenia spp.…”

Enrichment of big-leaf mahogany (Swietenia macrophylla King) in logging gaps in Bolivia: The effects of planting method and silvicultural treatments on long-term seedling survival and growth

“…In both regions many natural populations of mahogany have been so 0378-1127/$ -see front matter Ó 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.foreco.2011.08.020 depleted by legal and illegal logging as to be commercially and, in some cases, ecologically unviable (Veríssimo et al, 1995;Kometter et al, 2004;Schulze et al, 2008;Grogan et al, 2010). Although mahogany's adaptability to a wide range of ecological conditions suggests greater resilience to logging than is generally acknowledged (Mayhew and Newton, 1998;Brown et al, 2003;Grogan et al, 2003a), mahogany seedlings are usually scarce or absent from heavily logged forests (Lamb, 1966;Dickinson and Whigham, 1999;Grogan et al, 2003b;Grogan and Galvão, 2006).…”

“…By the mid 1990s in Mesoamerica, deforestation and over harvesting had reduced mahogany's original geographic range to roughly one third (Calvo and Rivera, 2000). In South America, the commercial range of mahogany has been reduced to an estimated 94 million hectares, or 34% of the historic range (Grogan et al, 2010). In both regions many natural populations of mahogany have been so 0378-1127/$ -see front matter Ó 2011 Elsevier B.V. All rights reserved.…”

Smallholder Forestry in the Western Amazon: Outcomes from Forest Reforms and Emerging Policy Perspectives

“…As a result, smallholders engage in vigorous timber networks, where intermediaries play a central role but in which buyers who reside in cities, have a major influence on prices [108,109]. Specialized chainsaw operators as well as intermediaries who have their own harvesting teams, organize the logging activities.…”