Political and economic initiatives intended to increase energy production while reducing carbon emissions are driving demand for solar energy. Consequently, desert regions are now targeted for development of large-scale photovoltaic solar energy facilities. Where vegetation communities are left intact or restored within facilities, ground-mounted infrastructure may have negative impacts on desert-adapted plants because it creates novel rainfall runoff and shade conditions. We used experimental solar arrays in the Mojave Desert to test how these altered conditions affect population dynamics for a closely related pair of native annual plants: rare Eriophyllum mohavense and common E. wallacei. We estimated aboveground demographic rates (seedling emergence, survivorship, and fecundity) over 7 yr and used seed bank survival rates from a concurrent study to build matrix models of population growth in three experimental microhabitats. In drier years, shade tended to reduce survival of the common species, but increase survival of the rare species. In a wet year, runoff from panels tended to increase seed output for both species. Population growth projections from microhabitat-specific matrix models showed stronger effects of microhabitat under wetter conditions, and relatively little effect under dry conditions (lack of rainfall was an overwhelming constraint). Performance patterns across microhabitats in the wettest year differed between rare and common species. Projected growth of E. mohavense was substantially reduced in shade, mediated by negative effects on aboveground demographic rates. Hence, the rare species were more susceptible to negative effects of panel infrastructure in wet years that are critical to seed bank replenishment. Our results suggest that altered shade and water runoff regimes associated with energy infrastructure will have differential effects on demographic transitions across annual species and drive population-level processes that determine local abundance, resilience, and persistence.

中文翻译：

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与太阳能开发相关的微生境改变了两个沙漠年的人口统计

旨在增加能源生产同时减少碳排放的政治和经济举措正在推动对太阳能的需求。因此，沙漠地区现在成为发展大型光伏太阳能设施的目标。如果植被群落完好无损或在设施内恢复，地面基础设施可能会对适应沙漠的植物产生负面影响，因为它会产生新的降雨径流和遮荫条件。我们在莫哈韦沙漠使用实验性太阳能电池阵列来测试这些改变的条件如何影响一对密切相关的本地一年生植物的种群动态：稀有的Eriophyllum mohavense和常见的E. wallacei. 我们估计了超过 7 年的地上人口统计率（出苗率、存活率和繁殖力），并使用来自一项同时研究的种子库存活率来建立三个实验性微生境中人口增长的矩阵模型。在较干燥的年份，遮荫往往会降低常见物种的存活率，但会增加稀有物种的存活率。在雨年，面板的径流往往会增加这两个物种的种子产量。来自微生境特定矩阵模型的种群增长预测显示，微生境在潮湿条件下的影响更强，而在干燥条件下影响相对较小（缺乏降雨是一个压倒性的限制因素）。在最潮湿的年份，微生境的表现模式在稀有物种和常见物种之间存在差异。E. mohavense的预计增长由于对地上人口比例的负面影响，阴影显着减少。因此，稀有物种在雨季更容易受到面板基础设施的负面影响，这对种子库的补充至关重要。我们的研究结果表明，与能源基础设施相关的改变的阴影和径流机制将对跨年度物种的人口转变产生不同的影响，并推动决定当地丰度、恢复力和持久性的人口水平过程。