Balancing Beetles and Timber Demand
Reduced-impact logging is a practice that grew popular in the 1990s as a way to meet the increasing, international demand for timber without impinging on biodiversity basically by extracting less tress. Today, though, that practice is coming back to bite us according to a new study of its impacts in the Brazilian Amazon rainforest focused on dung beetle populations. Conversely, activists in Białowieża (pron.: be-ah-wo-VE-zha), Poland both protested and counter-protested intense logging deliberately authorized by the government to combat a rampant outbreak of the spruce bark beetle whom the government claimed poses an eminent threat tot he Europe’s most primeval forest.
The conflict over the Białowieża Forest made headlines at the beginning of the month. The contention was multifaceted but primarily dealt with a legitimate threat that beetles posed to the forest and whether or not logging was an adequate solution. The new study in the Brazilian Amazon centers around a specific kind of logging called reduced-impact or selective logging, and it looks at a different type of beetle as well.
The dung beetle is viewed as a so-called “ecosystem engineer” because of its potential to reshape the landscape. It’s value to the natural progression of ecosystem change is significantly hampered, however, by even the slightest timber extraction. As such, even selective logging, the preferred logging of the ‘90s, disrupts the dung beetle’s habits and populations by greatly diminishing species diversity. There are already loads of pre-existing studies on various amphibians, mammals, birds and invertebrates the world over that illustrate this same finding, making it much less debatable in the eyes of experts that timber extraction, no matter how light or selective, greatly impinges on biodiversity.
The new research is rather extensive, and it implies that reduced-impact logging techniques need to be stopped in order to allow for “land-sparing” timber extraction strategies to take over. Ideally, this would yield a patchwork of intact forest reserves and densely logged sites. Selective logging strategies proliferated throughout the 1990s and are now used all over the world. The purpose is to preserve biodiversity and protect naturally-occurring ecosystem functions while commercially extracting valuable timber because, though biodiversity must be safeguarded, civilization inherently and conceptually requires a great deal of timber.
Some of the latest research was published online in the open-access journal, Biological Conversation, and it concentrated on dung beetle species diversity across 34 Amazonian sites in Pará, Brazil. The United Nations Food and Agriculture Organization (FAO) developed a 30-year cutting cycle that is now being observed as the reason why these Amazon sites endured intense logging to the tune of eight trees per hectare very suddenly. The research team concluded that even this low-intensity cutting cycle drastically impinged on dung beetle populations; removing between three and 35 trees in an expanse of 10 hectares (25 acres), in fact, resulted in one to eight less dung beetle species thereafter, which represents a proportionally dangerous precedent according to ecologist Filipe Franca at Lancaster University.
Franca spearheaded the study and says, “Even low levels of timber removal can lead to the loss of forest biodiversity and ecosystem functioning.” The logging techniques inevitably damage nearby trees as well as undergrowth no matter how selective they may be, which is what Franca says is responsible for such sharp declines in the dung beetle species indigent to the forest. In other words, it’s an inexact procedure and hardly a scientific one.
This is part of what complicates the debate in Poland over Białowieża Forest. Poland’s State Forests, a bureau tasked with managing forests nationwide, announced that the forest was threatened by the spruce bark beetle and that logging was the only way to counteract the threat. Polish Environment Minister Jan Szyszko tripled the amount of permissible logging in the forest for that reason, which resulted in protests from environmental groups this year who claim that logging is far more detrimental to the environment than anything the beetle would do. Adding to the contention is the historical significance of the forest for the entire continent.
Jaboury Ghazoul, ETH Zurich ecologist from Switzerland, said that more research unfortunately won’t resolve the conflict. “What kinds of forests do we want to end up with? That’s largely a question of values,” he explained. “It’s not something that can be easily resolved, if at all, by science,” which explains why the fight rages on. Research is as definitive as it needs to be about what the real threats to the forest are, but some feel that economic demands outweigh what they consider to be “sentiment” regarding the last of Europe’s ancient, lowland forests. Beyond that, selective logging doesn’t perfectly control outbreaks like these anyway, especially those like that in Poland that are fueled partly by drought.
“The big outbreaks don’t work that way,” according to Diana Six, an entomologist from the University of Montana, Missoula. “You can’t stop them.” The only difference caused by continued logging is that lots of species of other animals in the forest will lose available habitats that dung beetles would have otherwise created for them, which is likely to yield a ripple effect of sorts with unpredictable ramifications.
[리서치페이퍼=Cedric Dent 기자]