Data from: Forecasting the cumulative effects of multiple stressors on breeding habitat for a steeply declining aerial insectivorous songbird, the olive-sided flycatcher (Contopus cooperi)

AbstractTo halt ongoing loss in biodiversity, there is a need for landscape-level management recommendations that address cumulative impacts of anthropogenic and natural disturbances on wildlife habitat. We examined the cumulative effects of logging, roads, land-use change, fire, and bark beetle outbreaks on future habitat for olive-sided flycatcher (Contopus cooperi), a steeply declining aerial insectivorous songbird, in Canada's western boreal forest. To predict the occurrence of olive-sided flycatcher we developed a suite of habitat suitability models using point count surveys (1997–2011) spatially- and temporally-matched with forest inventory data. Flycatcher occurrence was positively associated with small (~10 ha) 10–20-year-old clearcuts, and with 10–100% tree mortality due to mountain pine beetle (Dendroctonus ponderosae) outbreaks, but we found no association with roads or distance to water. We used the parameter estimates from the best-fit habitat suitability models to inform spatially explicit state-and-transition simulation models to project change in habitat availability from 2020 to 2050 under six alternative scenarios (three management × two fire alternatives). The simulation models projected that the cumulative effects of land use conversion, forest harvesting, and fire will reduce the area of olive-sided flycatcher habitat by 16–18% under Business As Usual management scenarios and by 11–13% under scenarios that include protection of 30% of the land base. Scenarios limiting the size of all clearcuts to ≤ 10 ha resulted in a median habitat loss of 4–6%, but projections were highly variable. Under all three management alternatives, a 50% increase in fire frequency (expected due to climate change) exacerbated habitat loss. The projected losses of habitat in western boreal forest, even with an increase in protected areas, imply that reversing the ongoing population declines of olive-sided flycatcher and other migratory birds will require attention to forest management beyond protected areas. Further work should examine the effects of multiple stressors on the demographic mechanisms driving change in aerial insectivore populations, including stressors on the wintering grounds in South America, and should aim to adapt the design of protected areas and forest management policies to projected climate-driven increases in the size and frequency of wildfires., Usage notesAs outlined in the Supplementary materials, this file contains all of the files required to run and view the land use and land cover change (LULC) results of the paper's simulations using the ST-Sim package for SyncroSim software.  To reduce file sizes, this archive contains all simulation inputs but no outputs.  Code to post process LULC outputs into habitat is available on GitHub: https://github.com/ApexRMS/osfl

为遏制生物多样性持续丧失，亟需制定景观尺度的管理方案，以应对人为与自然干扰对野生动物生境的累积影响。本研究针对加拿大西部北方森林（boreal forest）中的橄榄侧纹捕蝇鹟（olive-sided flycatcher, Contopus cooperi）——一种种群急剧下降的空中食虫鸣禽——的未来生境，分析了伐木、道路建设、土地利用变化、火灾以及树皮甲虫虫害爆发的累积效应。

为预测橄榄侧纹捕蝇鹟的出现概率，研究团队利用1997-2011年的点计数调查法（point count surveys）数据，结合时空匹配的森林清查数据，构建了一系列生境适宜性模型（habitat suitability models）。结果显示，该鸟类的出现概率与面积约10公顷、林龄10-20年的皆伐迹地，以及因山松甲虫（Dendroctonus ponderosae）爆发导致10%-100%树木死亡率的区域呈正相关，但未发现其与道路或距水源距离存在关联。

研究采用最优生境适宜性模型的参数估计值，驱动空间显式状态转移模拟模型（state-and-transition simulation models），在六种替代情景（三种经营方案×两种火灾情景）下，预测2020年至2050年的生境面积变化。模拟结果显示，在常规经营情景（Business As Usual）下，土地利用转换、森林采伐与火灾的累积效应将使橄榄侧纹捕蝇鹟的生境面积减少16%-18%；在保护30%陆地面积的情景下，生境损失率为11%-13%。若将所有皆伐迹地的面积限制在10公顷以内，生境损失的中位数为4%-6%，但预测结果存在较高变异性。在所有三种经营方案中，火灾频率增加50%（预计由气候变化引发）会加剧生境损失。

即便在增加保护区面积的情景下，加拿大西部北方森林的生境预计仍将出现损失，这意味着要扭转橄榄侧纹捕蝇鹟及其他迁徙鸟类的种群下降趋势，需关注保护区以外的森林管理措施。未来研究应探究多重胁迫因子对驱动空中食虫鸣禽种群变化的种群统计机制的影响，包括南美越冬地的胁迫因子，并应致力于优化保护区设计与森林管理政策，以应对气候变化驱动的野火规模与频率上升带来的挑战。

使用说明：如补充材料所述，本归档文件包含了利用SyncroSim软件的ST-Sim软件包（ST-Sim package）运行并查看本文模拟所得土地利用与土地覆盖变化（Land Use and Land Cover Change，简称LULC）结果所需的全部文件。为压缩文件体积，本归档仅包含所有模拟输入数据，未包含输出结果。将LULC输出结果后处理为生境数据的代码可在GitHub获取：https://github.com/ApexRMS/osfl