Barve Narayani, Martin Craig E, Peterson A Townsend
Biodiversity Institute, University of Kansas, 1345 Jayhawk Blvd, Lawrence, KS 66045, USA Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66045, USA
Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66045, USA.
AoB Plants. 2015 Sep 10;7:plv108. doi: 10.1093/aobpla/plv108.
Species have geographic distributions constrained by combinations of abiotic factors, biotic factors and dispersal-related factors. Abiotic requirements vary across the life stages for a species; for plant species, a particularly important life stage is when the plant flowers and develops seeds. A previous year-long experiment showed that ambient temperature of 5-35 °C, relative humidity of >50 % and ≤15 consecutive rainless days are crucial abiotic conditions for Spanish moss (Tillandsia usneoides L.). Here, we explore whether these optimal physiological intervals relate to the timing of the flowering and fruiting periods of Spanish moss across its range. As Spanish moss has a broad geographic range, we examined herbarium specimens to detect and characterize flowering/fruiting periods for the species across the Americas; we used high-temporal-resolution climatic data to assess the availability of optimal conditions for Spanish moss populations during each population's flowering period. We explored how long populations experience suboptimal conditions and found that most populations experience suboptimal conditions in at least one environmental dimension. Flowering and fruiting periods of Spanish moss populations are either being optimized for one or a few parameters or may be adjusted such that all parameters are suboptimal. Spanish moss populations appear to be constrained most closely by minimum temperature during this period.
物种的地理分布受到非生物因素、生物因素和扩散相关因素组合的限制。一个物种在其整个生命阶段对非生物条件的需求各不相同；对于植物物种而言，一个特别重要的生命阶段是植物开花和结籽的时候。此前一项为期一年的实验表明，5-35°C的环境温度、>50%的相对湿度以及连续无雨天数≤15天是西班牙铁兰（Tillandsia usneoides L.）至关重要的非生物条件。在此，我们探究这些最佳生理区间是否与西班牙铁兰在其分布范围内开花和结果期的时间相关。由于西班牙铁兰具有广泛的地理分布范围，我们检查了植物标本馆的标本，以检测和描述该物种在美洲各地的开花/结果期；我们使用高时间分辨率的气候数据来评估每个种群开花期期间西班牙铁兰种群最佳条件的可获得性。我们探究了种群经历次优条件的时长，发现大多数种群在至少一个环境维度上经历次优条件。西班牙铁兰种群的开花和结果期要么针对一个或几个参数进行了优化，要么可能进行了调整，以至于所有参数都是次优的。在此期间，西班牙铁兰种群似乎受到最低温度的最严格限制。
