Encinas-Viso Francisco, McDonald-Spicer Christiana, Knerr Nunzio, Thrall Peter H, Broadhurst Linda
Centre for Australian National Biodiversity Research CSIRO Canberra ACT Australia.
The Australian National University Canberra ACT Australia.
Ecol Evol. 2020 Oct 31;10(23):13476-13487. doi: 10.1002/ece3.6952. eCollection 2020 Dec.
Restoring degraded landscapes has primarily focused on re-establishing native plant communities. However, little is known with respect to the diversity and distribution of most key revegetation species or the environmental and anthropogenic factors that may affect their demography and genetic structure. In this study, we investigated the genetic structure of two widespread Australian legume species ( and ) in the Murray-Darling Basin (MDB), a large agriculturally utilized region in Australia, and assessed the impact of landscape structure on genetic differentiation. We used AFLP genetic data and sampled a total of 28 and 30 sampling locations across southeastern Australia. We specifically evaluated the importance of four landscape features: forest cover, land cover, water stream cover, and elevation. We found that both species had high genetic diversity (mean percentage of polymorphic loci, 55.1% for versus. 64.3% for and differentiation among local sampling locations (: Φ = 0.301, 30%; : Φ = 0.235, 23%). Population structure analysis showed that both species had high levels of structure (6 clusters each) and admixture in some sampling locations, particularly . Although both species have a similar geographic range, the drivers of genetic connectivity for each species were very different. Genetic variation in seems to be mainly driven by geographic distance, while for , land cover appears to be the most important factor. This suggests that for the latter species, gene flow among populations is affected by habitat fragmentation. We conclude that these largely co-occurring species require different management actions to maintain population connectivity. We recommend active management of in the MDB to improve gene flow in the adversity of increasing disturbances ( droughts) driven by climate change and anthropogenic factors.
恢复退化景观主要侧重于重建本地植物群落。然而，对于大多数关键植被恢复物种的多样性和分布，以及可能影响其种群统计学和遗传结构的环境和人为因素，我们知之甚少。在本研究中，我们调查了澳大利亚墨累-达令盆地（MDB）两种广泛分布的豆科植物（和）的遗传结构，该盆地是澳大利亚一个农业利用广泛的大区域，并评估了景观结构对遗传分化的影响。我们使用AFLP遗传数据，在澳大利亚东南部总共对28个和30个采样地点进行了采样。我们特别评估了四种景观特征的重要性：森林覆盖、土地覆盖、水流覆盖和海拔。我们发现这两个物种都具有高遗传多样性（多态位点的平均百分比，为55.1%，而为64.3%），并且在当地采样地点之间存在分化（：Φ = 0.301，30%；：Φ = 0.235，23%）。种群结构分析表明，这两个物种都具有高水平的结构（各有6个聚类），并且在一些采样地点存在混合现象，特别是。尽管这两个物种的地理分布范围相似，但每个物种的遗传连通性驱动因素却非常不同。的遗传变异似乎主要由地理距离驱动，而对于，土地覆盖似乎是最重要的因素。这表明对于后一个物种，种群间的基因流受到栖息地破碎化的影响。我们得出结论，这些在很大程度上共存的物种需要不同的管理措施来维持种群连通性。我们建议在墨累-达令盆地对进行积极管理，以在气候变化和人为因素导致的干扰（干旱）增加的逆境中改善基因流。
