Foundation species play a disproportionate role in maintaining biodiversity and ecosystem functioning. Improved understanding of how environmental factors influence the distribution and population structure of foundation species therefore contributes to management and conservation of entire ecosystems. We surveyed subtidal kelp forests within four regions of the U.K., distributed over 9° of latitude and a mean sea temperature gradient of ~ 2.5°C. Our aims were: (1) to examine relationships between light availability and the structure and depth distribution of Laminaria hyperborea populations and (2) to determine whether depth-related patterns were consistent across regions with different temperature regimes. We recorded marked depth-related shifts in structure with decreasing light levels strongly correlated with declines in kelp density, cover, plant biomass, standing biomass, plant length, and age. We also recorded an effect of latitude; populations at our two colder, northernmost regions exhibited greater wet weight and length and higher standing biomass than populations in the warmer southern regions when under similar or even reduced light conditions, indicating an interactive effect of latitude, most likely related to temperature variability. We show that shifts in kelp population structure along depth gradients are strongly driven by light availability, although regional variability in the strength and nature of these relationships may be promoted by other factors such as temperature. Maximum depth penetration, standing biomass, plant density, and plant weight are useful indicators of light availability and, over time, could be monitored to detect changes in the quality of the overlying water column.

中文翻译：

---

检查区域尺度的温度和光照可用性变化对潮下带海带森林深度分布的影响

基础物种在维持生物多样性和生态系统功能方面发挥着不成比例的作用。因此，加深对环境因素如何影响基础物种的分布和种群结构的理解有助于管理和保护整个生态系统。我们调查了英国四个地区的潮下带海带森林，分布在 9° 的纬度和约 2.5°C 的平均海水温度梯度。我们的目标是：（1）检查光的可用性与海带结构和深度分布之间的关系人口和（2）确定与深度相关的模式是否在具有不同温度状态的区域之间是一致的。我们记录了显着的与深度相关的结构变化，光照水平的降低与海带密度、覆盖、植物生物量、站立生物量、植物长度和年龄的下降密切相关。我们还记录了纬度的影响；当光照条件相似或什至减弱时，我们两个较冷、最北端的地区的种群比较温暖的南部地区的种群表现出更大的湿重和长度以及更高的站立生物量，这表明纬度的相互作用效应，很可能与温度变化有关。我们表明，海带种群结构沿深度梯度的变化受到光照可用性的强烈驱动，尽管温度等其他因素可能会促进这些关系的强度和性质的区域差异。最大深度渗透、站立生物量、植物密度和植物重量是光照可用性的有用指标，并且随着时间的推移，可以监测以检测上覆水柱质量的变化。