July 19, 2012
Logging in Gabon, Central Africa. Photo by Rhett A. Butler.
"We are facing a global biodiversity and a climate change crisis and we cannot afford to continue to lose primary tropical forests—they are central to resolving both crises," authors Barbara Zimmerman with the International Conservation Fund for Canada and Cyril Kormos, Vice President for policy with the WILD Foundation, told mongabay.com. "Despite decades of trying to log sustainably, the rate of deforestation has barely dipped over the last 20 years, from 15 million hectares per year to 13 million hectares per year—and these are low estimates. Industrial logging has shown no capacity to keep forests standing. On the contrary, logging is usually the first step towards total clearing to make way for agricultural use."
The study found that just three rounds of logging in tropical forests resulted in the near-extinction of target trees in all major rainforest zones—South and Central America, Central Africa, and Southeast Asia—resulting not only in ecological disturbance but economic fallout.
Ecological and economic barriers
Deforestation for palm oil in Sabah, Malaysia. Often logged forests are then converted to plantations or pastures. Photo by Rhett A. Butler.
The very ecology of tropical rainforests—their rich biodiversity, unparalleled variety, and hugely complex interconnections between species—makes them particularly susceptible to disturbance. Targeting only a few key tree species in the forest, loggers quickly plunder these species while leaving the rest standing, rapidly changing the overall structure of the ecosystem. In this way, loggers undercut the very ecological system that allows their favored trees to replenish.
"Virtually all currently high-value timber species, are exceptionally long lived and slow growing, occur at low adult density, undergo high rates of seed and seedling mortality, sustain very sparse regeneration at the stand level, and rely on animal diversity for reproduction, all of which point to the conclusion that tropical trees probably need very large continuous areas of ecologically intact forest if they are to maintain viable population sizes," Zimmerman and Kormos write in their paper.
The particular ecology of these trees has resulted in most logging companies simply entering a primary forest, cutting all high-value species, and then leaving it to colonizers or razing everything for cattle pasture or monoculture plantations (such as pulp and paper, rubber, or palm oil).
"Logging in the tropics follows the same economic model as is evident in most of the world’s ocean fisheries," Zimmerman and Kormos write. "The most-valuable species are selectively harvested first, and when they are depleted, the next-most-valuable set is taken, until the forests are mined completely of their timber."
Boom and bust. Sawlog and veneer-log production for the Solomon Islands and five key South-East Asian nations (derived from FAOSTAT, 2011). Courtesy of Shearman et al 2012.
While initial logging can be quite profitable, later harvests bring in less-and-less money: fewer target trees can be found and the regenerative process for such species is compromised overall. Eventually industrial logging kills itself, leaving an economic vacuum that in accessible areas is often filled by conversion to pasture land, oil palm estates, industrial agriculture or timber plantations.
Some scientists have argued that the solution to this problem is to inject sustainable forest management practices into logging companies in the tropics. According to these sustainability proponents, this would ensure harvests over the long-term while protecting overall forest health.
Impact of various disturbance regimes on biodiversity in tropical forests. Chart based on Gibson et. al 2011. Photo by Rhett Butler. Click to enlarge
"We now know that under the present sustainable forestry management guidelines, tropical forests left to regenerate naturally will be composed largely of light-wooded tree species of no to low commercial value, whereas dense-wood, high-value timber species will experience severe population declines," Kormos and Zimmerman write, noting that current guidelines are far too lax to keep forests intact.
Giant rainforest tree in Sumatra. Photo by Rhett A. Butler.
"The key to a forest’s ability to recover most of its original attributes after selective logging is low harvest intensity," they write.
But, there is a reason why there are no industrial loggers in the tropics putting such stringent rules in place.
"The problem with implementing this kind of protocol is that it would substantially diminish harvestable timber volume while further increasing management and training costs, which would make the timber operation economically unviable," Zimmerman and Kormos told mongabay.com.
It's no wonder then that logging companies generally cut-and-run, a practice which has resulted in loggers moving from one untouched tropical forest to the next, always looking for the short-term gain. For example, after logging out most of the forests in Borneo, loggers moved into places like Sumatra. Now that Sumatra has been devastated—with many of its forests turned into monoculture plantations—industrial logging went to New Guinea and the Solomon Islands. Primary rainforest is vanishing worldwide.
Logging not a "middle way"
Zimmerman and Kormos’ paper is one among several that debates, sometimes heatedly, the role of logging in protecting or destroying tropical forests. For example, a paper in Conservation Letters recently came to a very different conclusion than Zimmerman and Kormos, describing well-managed logging as a middle way between conservation and outright destruction of tropical forests for agriculture or ranching.
"Selectively logged tropical forests, especially if they are logged gently and with care, retain most of their biodiversity and continue to provide ecosystem services such as carbon sequestration and hydrological functions," lead author of that study, Francis Putz with the University of Florida told mongabay.com in May.
Raw logs waiting for transport in Guyana. Photo by Jeremy Hance.
"There is no question that industrial logging is better than cattle pastures or oil palm or other plantations—but the fact that industrial logging is better than total forest conversion doesn’t mean we should subsidize it," Zimmerman and Kormos told mongabay.com. "Subsidies should be directed towards activities that maximize carbon, biodiversity and social benefits."
They also say some of the paper's findings are problematic. "The article includes introduced species in the biodiversity totals, and the biodiversity surveys cited were all done soon after logging and before a second harvest, so there would be an expectation that there would still be biodiversity left in the short term—the question is what happens to biodiversity in the medium term, in particular after a second harvest? In addition, the article states that a logged forest retains 76% of its carbon. But 24% of a forest's carbon is a very substantial amount of carbon emissions—it could take several decades just to recapture that carbon, whereas we need to be maximizing forest carbon right now."
Even more importantly, perhaps, is that economic problems remain, dooming many logged forests to total clearance.
"The 'middle way' does not make logging sustainable. The Putz et al article clearly acknowledges that the middle way does not achieve sustained timber yields. As a result, it does nothing to change the fundamental dynamic, which is that logging usually precedes conversion to higher value agriculture use. So the 'middle way' could actually make things worse—accelerating forest conversion," Zimmerman and Kormos say.
Aerial view of logging roads in Malaysian Borneo. Photos by Rhett A. Butler.
"REDD+ should not be used to subsidize industrial logging. The biodiversity and climate change crises are rapidly getting worse, and keeping primary forests intact is an essential part of the response to both crises. REDD funding should be reserved for activities that keep primary forests intact, such as community management and protected areas" Zimmernam and Kormos say. They note that REDD+, which is meant to pay countries to preserve forests as carbon reservoirs, would undercut its main goal, since even well-managed logging concessions lose significant carbon when trees are felled, especially large, old trees. In addition, logged forests are at significant risk of total carbon loss as a result of fire or conversion to agricultural use.
Still, Zimmerman and Kormos, say logging can occur in tropical forests, only it should be small operations run by local communities, and not the industrial logging that dominates the trade today.
"Community logging works when it is implemented at non-industrial scales by communities that have a vested interest in being good stewards of their land," they say. The key here is that local communities govern their own forests, which takes away the cut-and-run problem. In addition, such programs must be supported by the national government. This is where REDD+ could really make a difference.
"The most important reason that these successful local-scale sustainable forestry management models have not been scaled up to secure the world’s remaining tropical forests is a lack of funding—-a situation that REDD+ investment might correct," the authors note.
Gabon. Photo by Rhett A. Butler.