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Effect of clearcutting operations on the survival rate of a small mammal.

Escobar MA, Uribe SV, Chiappe R, Estades CF - PLoS ONE (2015)

Bottom Line: However, this approach does not separate the effect of changes in habitat attributes from direct mortality produced by the intensive use of heavy machinery required for cutting down trees and dragging them to a road.Our observations suggest that, instead of fleeing the area, the response of long-haired Akodonts to the approaching machinery is to hide under the forest litter or in burrows, which exposes them to a serious risk of death.The real mortality rate associated to clearcutting may be higher than that estimated by us because of some methodological biases (i.e. individuals with crushed radiotransmitters not recorded) and the fact that additional mortality sources may affect the population in the weeks following logging operations (e.g., higher exposure to predation, effects of site preparation for the new plantation, etc).

View Article: PubMed Central - PubMed

Affiliation: Laboratorio de Ecología de Vida Silvestre, Facultad de Ciencias Forestales y Conservación de la Naturaleza, Universidad de Chile, Santiago, Chile.

ABSTRACT
Clearcutting is a common timber harvesting technique that represents a significant and abrupt change in habitat conditions for wildlife living in industrial forests. Most research on this type of impact has focused on comparing populations or communities in mature forests/plantations and the resulting clearcut stands. However, this approach does not separate the effect of changes in habitat attributes from direct mortality produced by the intensive use of heavy machinery required for cutting down trees and dragging them to a road. Because knowing the fate of individuals after a disturbance is important for modelling landscape-scale population dynamics in industrial forests, we conducted a study in South-Central Chile to understand the short-term response to clearcutting operations of the long-haired Akodont (Abrothrix longipillis), a forest specialist mouse. Between 2009 and 2013 we radiotracked a total of 51 adult male Akodonts, before, during and after the clearcutting of the pine plantations in which they lived. A minimum of 52.4% of the individuals died as a direct cause of the timbering operations, being crushed by vehicles or logs during logging operations. Our observations suggest that, instead of fleeing the area, the response of long-haired Akodonts to the approaching machinery is to hide under the forest litter or in burrows, which exposes them to a serious risk of death. The real mortality rate associated to clearcutting may be higher than that estimated by us because of some methodological biases (i.e. individuals with crushed radiotransmitters not recorded) and the fact that additional mortality sources may affect the population in the weeks following logging operations (e.g., higher exposure to predation, effects of site preparation for the new plantation, etc).

No MeSH data available.


Related in: MedlinePlus

Daily survival probabilities for adult male long-haired Akodonts, before, during and after the logging of the pine plantations in which they lived (2009–2010).Bars indicate standard error. Different letters on the top of each value indicate significant differences of contrast tests at a 95% confidence level.
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pone.0118883.g003: Daily survival probabilities for adult male long-haired Akodonts, before, during and after the logging of the pine plantations in which they lived (2009–2010).Bars indicate standard error. Different letters on the top of each value indicate significant differences of contrast tests at a 95% confidence level.

Mentions: Most of the recovered dead mice had, apparently, been hiding underneath the forest litter or in burrows when they were crushed by the skidders or timber harvesters. In one case we had to dig up to 50 cm in the ground to recover a dead Akodont whose burrow had collapsed under the weight of the machinery. In other cases, the individuals seem to have died crushed by the logs that were dragged around the site. In fact, for six individuals we could only assume the cause of death because we could not reach to their bodies, as the signals came from underneath big piles of logs or harvest debris. The comparison of the Trent and Rongstad estimators [38] for the three experimental stages (Fig. 3), showed that there was a significant reduction in the Akodont survival rate from the pre-logging to the logging phase (Z = 6.24, p < 0.05, n = 28). Survival rate increased slightly after logging operations had ended, but it was still significantly lower than during the pre-logging phase (Z = 2.44, p < 0.05, n = 28).


Effect of clearcutting operations on the survival rate of a small mammal.

Escobar MA, Uribe SV, Chiappe R, Estades CF - PLoS ONE (2015)

Daily survival probabilities for adult male long-haired Akodonts, before, during and after the logging of the pine plantations in which they lived (2009–2010).Bars indicate standard error. Different letters on the top of each value indicate significant differences of contrast tests at a 95% confidence level.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4352083&req=5

pone.0118883.g003: Daily survival probabilities for adult male long-haired Akodonts, before, during and after the logging of the pine plantations in which they lived (2009–2010).Bars indicate standard error. Different letters on the top of each value indicate significant differences of contrast tests at a 95% confidence level.
Mentions: Most of the recovered dead mice had, apparently, been hiding underneath the forest litter or in burrows when they were crushed by the skidders or timber harvesters. In one case we had to dig up to 50 cm in the ground to recover a dead Akodont whose burrow had collapsed under the weight of the machinery. In other cases, the individuals seem to have died crushed by the logs that were dragged around the site. In fact, for six individuals we could only assume the cause of death because we could not reach to their bodies, as the signals came from underneath big piles of logs or harvest debris. The comparison of the Trent and Rongstad estimators [38] for the three experimental stages (Fig. 3), showed that there was a significant reduction in the Akodont survival rate from the pre-logging to the logging phase (Z = 6.24, p < 0.05, n = 28). Survival rate increased slightly after logging operations had ended, but it was still significantly lower than during the pre-logging phase (Z = 2.44, p < 0.05, n = 28).

Bottom Line: However, this approach does not separate the effect of changes in habitat attributes from direct mortality produced by the intensive use of heavy machinery required for cutting down trees and dragging them to a road.Our observations suggest that, instead of fleeing the area, the response of long-haired Akodonts to the approaching machinery is to hide under the forest litter or in burrows, which exposes them to a serious risk of death.The real mortality rate associated to clearcutting may be higher than that estimated by us because of some methodological biases (i.e. individuals with crushed radiotransmitters not recorded) and the fact that additional mortality sources may affect the population in the weeks following logging operations (e.g., higher exposure to predation, effects of site preparation for the new plantation, etc).

View Article: PubMed Central - PubMed

Affiliation: Laboratorio de Ecología de Vida Silvestre, Facultad de Ciencias Forestales y Conservación de la Naturaleza, Universidad de Chile, Santiago, Chile.

ABSTRACT
Clearcutting is a common timber harvesting technique that represents a significant and abrupt change in habitat conditions for wildlife living in industrial forests. Most research on this type of impact has focused on comparing populations or communities in mature forests/plantations and the resulting clearcut stands. However, this approach does not separate the effect of changes in habitat attributes from direct mortality produced by the intensive use of heavy machinery required for cutting down trees and dragging them to a road. Because knowing the fate of individuals after a disturbance is important for modelling landscape-scale population dynamics in industrial forests, we conducted a study in South-Central Chile to understand the short-term response to clearcutting operations of the long-haired Akodont (Abrothrix longipillis), a forest specialist mouse. Between 2009 and 2013 we radiotracked a total of 51 adult male Akodonts, before, during and after the clearcutting of the pine plantations in which they lived. A minimum of 52.4% of the individuals died as a direct cause of the timbering operations, being crushed by vehicles or logs during logging operations. Our observations suggest that, instead of fleeing the area, the response of long-haired Akodonts to the approaching machinery is to hide under the forest litter or in burrows, which exposes them to a serious risk of death. The real mortality rate associated to clearcutting may be higher than that estimated by us because of some methodological biases (i.e. individuals with crushed radiotransmitters not recorded) and the fact that additional mortality sources may affect the population in the weeks following logging operations (e.g., higher exposure to predation, effects of site preparation for the new plantation, etc).

No MeSH data available.


Related in: MedlinePlus