Fire Management, Managed Relocation, and Land Conservation Options for Long‐Lived Obligate Seeding Plants under Global Changes in Climate, Urbanization, and Fire Regime
Fire Management, Managed Relocation, and Land Conservation Options for Long‐Lived Obligate Seeding Plants under Global Changes in Climate, Urbanization, and Fire Regime
复制标题
全球气候、城市化和火灾制度变化下长寿命定种植物的火灾管理、有管理的搬迁和土地保护方案
作者：
T. Bonebrake;A. Syphard;J. Franklin;K. Anderson;H. Akçakaya;Toni L. Mizerek;C. Winchell;H. Regan
大多数物种面临多重人为破坏。很少有研究量化多种威胁对受保护物种的累积影响，而且很少有研究根据这些威胁量化多种保护干预措施的潜在相对价值。我们将空间分布和种群生存力模型联系起来，探索在预计的气候变化、城市化和火灾状况变化下对对高火灾频率敏感的长寿专性播种植物物种的保护干预措施，这是许多火灾易发生态系统（包括地中海型生态系统的生物多样性热点）中的主要植物功能类型。首先，我们调查了现有栖息地保护计划下有或没有土地保护的景观中植物种群数量下降的相对风险。其次，我们模拟了在两种预计的气候变化情景下，将幼苗和种子从预计栖息地面积下降的大片土地重新安置到栖息地面积增加的两个无人居住的接收地块的有效性。最后，我们对 8 个火灾返回间隔 (FRI) 进行了建模，近似有效控制火灾频率的不同管理策略的结果。总是，只有当 FRI 维持在最低水平或高于最低水平时，长寿的专性播种群体才保持活力。根据气候变化情景，土地保护和苗木迁移工作在不同程度上减轻了气候变化和土地利用变化对专性播种种群的影响，但这些努力都没有像频繁的种子迁移那样有效。虽然没有一个模型策略能够完全补偿土地利用和气候变化的影响，但管理多种威胁的综合方法可能会减少复杂景观中物种数量的下降。如果忽视其他威胁，旨在减轻单一威胁影响的保护计划可能会失败。
Most species face multiple anthropogenic disruptions. Few studies have quantified the cumulative influence of multiple threats on species of conservation concern, and far fewer have quantified the potential relative value of multiple conservation interventions in light of these threats. We linked spatial distribution and population viability models to explore conservation interventions under projected climate change, urbanization, and changes in fire regime on a long‐lived obligate seeding plant species sensitive to high fire frequencies, a dominant plant functional type in many fire‐prone ecosystems, including the biodiversity hotspots of Mediterranean‐type ecosystems. First, we investigated the relative risk of population decline for plant populations in landscapes with and without land protection under an existing habitat conservation plan. Second, we modeled the effectiveness of relocating both seedlings and seeds from a large patch with predicted declines in habitat area to 2 unoccupied recipient patches with increasing habitat area under 2 projected climate change scenarios. Finally, we modeled 8 fire return intervals (FRIs) approximating the outcomes of different management strategies that effectively control fire frequency. Invariably, long‐lived obligate seeding populations remained viable only when FRIs were maintained at or above a minimum level. Land conservation and seedling relocation efforts lessened the impact of climate change and land‐use change on obligate seeding populations to differing degrees depending on the climate change scenario, but neither of these efforts was as generally effective as frequent translocation of seeds. While none of the modeled strategies fully compensated for the effects of land‐use and climate change, an integrative approach managing multiple threats may diminish population declines for species in complex landscapes. Conservation plans designed to mitigate the impacts of a single threat are likely to fail if additional threats are ignored.