Durrant Rowan, Hamede Rodrigo, Wells Konstans, Lurgi Miguel
Department of Biosciences, Swansea University, Singleton Park, Swansea SA2 8PP, UK.
School of Natural Sciences, University of Tasmania, Hobart, TAS 7001, Australia.
Pathogens. 2021 Dec 8;10(12):1592. doi: 10.3390/pathogens10121592.
Metapopulation structure plays a fundamental role in the persistence of wildlife populations. It can also drive the spread of infectious diseases and transmissible cancers such as the Tasmanian devil facial tumour disease (DFTD). While disrupting this structure can reduce disease spread, it can also impair host resilience by disrupting gene flow and colonisation dynamics. Using an individual-based metapopulation model we investigated the synergistic effects of host dispersal, disease transmission rate and inter-individual contact distance for transmission, on the spread and persistence of DFTD from local to regional scales. Disease spread, and the ensuing population declines, are synergistically determined by individuals' dispersal, disease transmission rate and within-population mixing. Transmission rates can be magnified by high dispersal and inter-individual transmission distance. The isolation of local populations effectively reduced metapopulation-level disease prevalence but caused severe declines in metapopulation size and genetic diversity. The relative position of managed (i.e., isolated) local populations had a significant effect on disease prevalence, highlighting the importance of considering metapopulation structure when implementing metapopulation-scale disease control measures. Our findings suggest that population isolation is not an ideal management method for preventing disease spread in species inhabiting already fragmented landscapes, where genetic diversity and extinction risk are already a concern.
集合种群结构在野生动物种群的存续中起着基础性作用。它还能推动传染病和可传播癌症的传播,比如袋獾面部肿瘤病(DFTD)。虽然破坏这种结构可以减少疾病传播,但也会通过扰乱基因流动和殖民动态来削弱宿主的恢复力。我们使用基于个体的集合种群模型,研究了宿主扩散、疾病传播率以及个体间传播的接触距离对DFTD从局部到区域尺度的传播和存续的协同效应。疾病传播以及随之而来的种群数量下降,是由个体扩散、疾病传播率和种群内混合情况协同决定的。高扩散率和个体间传播距离会放大传播率。局部种群的隔离有效降低了集合种群层面的疾病患病率,但导致了集合种群规模和遗传多样性的严重下降。受管理(即隔离)的局部种群的相对位置对疾病患病率有显著影响,这凸显了在实施集合种群尺度的疾病控制措施时考虑集合种群结构的重要性。我们的研究结果表明,对于栖息在已经破碎化景观中的物种,在遗传多样性和灭绝风险已经令人担忧的情况下,种群隔离并非预防疾病传播的理想管理方法。