The pine beetles are in the beginning phase of a massive range expansion. Winter temperatures are now rarely cold enough to keep the beetle larvae in check, and every year the beetles kill more lodgepole pine. This expansion in range has brought them to the forests in Alberta, where the forest transitions from lodgepole into jack pine in a hybridized forest. The worry has been that the mountain pine beetle might be able to infect other pines, such as jack pine, which stretches across the Canadian shield and as far East as Nova Scotia.
A study published this May tested individuals from this hybrid forest. It had been very difficult to distinguish between the lodgepoles, the jack pines, and their hybrids, even using a wide array of molecular biology techniques. This new study used something called microsatellite markers; this technique identifies repeating units of DNA in the non-coding region of a gene. Over time, populations tend towards a value that characterize the entire population. This technique has been used to distinguish between hybrids for many other species.
The team was able to successfully distinguish between the hybrids and the jack and lodgepole pines. With this important step covered, they began to test the hybrid forest for evidence of beetle transition. They tested 678 trees from 25 different locations, and found evidence for the first time of pupal chambers in the jack pine, indicating that the insects had completed their larval stages in the jack pine.
This finding is a critical first step. Forest management best practices will depend now on what further information can be learned from this initial finding. Here's some figures that illustrate the potential damage this expansion in range could represent:
In the left pane, the range of the lodgepole pine. In the right pane, the jack pine range.
Reference:
CULLINGHAM, C. I., COOKE, J. E. K., DANG, S., DAVIS, C. S., COOKE, B. J. and COLTMAN, D. W. (2011), Mountain pine beetle host-range expansion threatens the boreal forest. Molecular Ecology, 20: 2157–2171. doi: 10.1111/j.1365-294X.2011.05086.x
A study published this May tested individuals from this hybrid forest. It had been very difficult to distinguish between the lodgepoles, the jack pines, and their hybrids, even using a wide array of molecular biology techniques. This new study used something called microsatellite markers; this technique identifies repeating units of DNA in the non-coding region of a gene. Over time, populations tend towards a value that characterize the entire population. This technique has been used to distinguish between hybrids for many other species.
The team was able to successfully distinguish between the hybrids and the jack and lodgepole pines. With this important step covered, they began to test the hybrid forest for evidence of beetle transition. They tested 678 trees from 25 different locations, and found evidence for the first time of pupal chambers in the jack pine, indicating that the insects had completed their larval stages in the jack pine.
This finding is a critical first step. Forest management best practices will depend now on what further information can be learned from this initial finding. Here's some figures that illustrate the potential damage this expansion in range could represent:
In the left pane, the range of the lodgepole pine. In the right pane, the jack pine range.
Reference:
CULLINGHAM, C. I., COOKE, J. E. K., DANG, S., DAVIS, C. S., COOKE, B. J. and COLTMAN, D. W. (2011), Mountain pine beetle host-range expansion threatens the boreal forest. Molecular Ecology, 20: 2157–2171. doi: 10.1111/j.1365-294X.2011.05086.x
Now even more species of trees are at risk. The ash tree is basically wiped out, the mountain pine is in dire straits, and now this? Stupid freaking bugs!
