Coupled Biogeochemical Cycles in Human Ecosystems: Stoichiometry, Hydrology, Connectiveness, and Culture

Brezonik 0322065该提案旨在扩大我们对人类生态系统中地球化学循环的理解。我们的主要问题是：城市和农场中的人类如何改变地球化学循环？我们将使用四重耦合概念来解决这个问题：（i）水文和元素循环之间，（ii）元素之间（化学计量），（iii）跨空间尺度（从家庭到地区），以及（iv）人类行为和元素循环之间。元素周期由三个关键尺度的空间连接控制。要素在家庭（城市景观的关键组成部分）及其周围环境之间、流域内和流域之间（即，从上游小流域到下游大流域，以及主要生态系统类型之间（例如，从农村到城市）。这种运动中的一些是故意控制的（例如，食物进口到城市），但大部分不是（例如，氮氧化物从汽车和景观中转移到大气中。此外，在景观中存在着不成比例的养分输入、转化和损失的“热点”。 人类主导的生态系统的复杂性是我们对其生物地球化学循环的理解落后于自然系统的原因之一。 然而，出于两个原因，现在是时候面对这种复杂性并发展这种理解了。首先，我们必须，作为一个生存问题。第二，我们可以;我们获取、存储和使用数据的能力已经达到了这样一个程度，我们可以期望将这种复杂性分解到一个有用的程度，并开发新的管理模式。

Brezonik0322065This proposal seeks to expand our understanding of biogeochemical cycles in human ecosystems. Our main question is: how do humans in cities and on farms alter biogeochemical cycles? We will address this question using a fourfold concept of coupling: (i) between hydrology and element cycling, (ii) among elements (stoichiometry), (iii) across spatial scales (from households to regions), and (iv) between human behavior and element cycling. Element cycles are controlled by spatial connections at three key scales. Elements move between households (which are key components of urban landscapes) and their surroundings, within and between watersheds (i.e., hierarchically from small upstream (low-order) watersheds downstream to larger, higher-order ones), and between major ecosystem types (e.g., from farm to city). Some of this movement is deliberately controlled (e.g., food import to cities), but a large portion is not (e.g., movement of NOx from autos and landscapes to the atmosphere. Moreover, there are "hotspots" within landscapes where disproportionate nutrient inputs, transformations, and losses occur. The complexity of human-dominated ecosystems is one reason why our understanding of their biogeochemical cycles has lagged behind that of natural systems. Nevertheless, for two reasons, now is the time to confront this complexity and develop this understanding. First, we must, as a matter of survival. Second, we can; our ability to acquire, store, and use data has reached the point that we can expect to unravel this complexity to a useful degree and develop new management paradigms.