Subterranean streams represent unique heterotrophic ecosystems, usually supported by organic matter imported from the surface. Traditionally, the biological communities from subterranean streams were characterized as simple associations, with low diversity and species abundance, comprising mostly aquatic invertebrates connected by few trophic links compared with those of the surface. However, these features have not yet been described in the wider context of fluxes of energy and nutrients through food webs along a gradual switch from autotrophy (dominated by photosynthesis) towards heterotrophy (dominated by detritus) following the surface–subterranean continuum. Combining the most recent predictions of Ecological Stoichiometry and the Metabolic Theory of Ecology, this article provides a theoretical framework aiming to explain the patterns observed along the surface–subterranean continuum in streams. It is predicted that the main factors constraining the structure and functioning of communities and food webs are the decline in the quantity and diversity of basal resources along this gradient, along with nutrients availability in water that affects food quality. With increasing availability of dissolved nutrients in water, sinking-cave streams are hypothesized to fluctuate between being N and/ or P co-limited to C-limited. Combined, the quantity, quality, and diversity of basal resources regulate subterranean aquatic communities through bottom–up mechanisms, reflected in a decreased flux of macronutrients through food webs. The consequences of these bottom–up effects are decreased abundance, biomass, secondary production, consumption rate, and mean body size of communities, together with potential increases in the elemental imbalance for macronutrients, omnivory, trophic position, and niche width and overlap among aquatic consumers along the surface–subterranean continuum. The bottom–up effects induce changes in the topology of stream food webs, which become shorter, with lower trophic diversity at the base of the network, but increased connectance along this environmental gradient.

地下溪流代表了独特的异养生态系统，通常由从地表输入的有机物质支持。传统上，来自地下溪流的生物群落的特征是简单的关联，多样性和物种丰度低，主要由水生无脊椎动物组成，与地表相比，几乎没有营养联系。然而，这些特征尚未在更广泛的背景下描述，即能量和营养物质通过食物网，沿着地表 - 地下连续体从自养（以光合作用为主）向异养（以碎屑为主）逐渐转变的更广泛背景下进行描述。结合生态化学计量学和生态学代谢理论的最新预测，本文提供了一个理论框架，旨在解释沿地表-地下连续体在溪流中观察到的模式。据预测，限制群落和食物网结构和功能的主要因素是沿着这一梯度的基础资源的数量和多样性下降，以及影响食物质量的水中营养物质的可用性。随着水中溶解养分的可用性增加，下沉洞穴流被假设在 N 和/或 P 共同限制到 C 限制之间波动。综合起来，基础资源的数量、质量和多样性通过自下而上的机制调节地下水生群落，反映在通过食物网的常量营养素通量减少。这些自下而上效应的后果是丰度、生物量、二次生产、消费率和群落的平均体型，以及大量营养素、杂食性、营养位置和生态位宽度的元素失衡的潜在增加，以及沿地表 - 地下连续体的水生消费者之间的重叠。自下而上的效应导致河流食物网拓扑结构发生变化，食物网变得更短，网络底部的营养多样性较低，但沿此环境梯度的联系增加。