Nutrient controls on ecosystem dynamics: the Chesapeake mesohaline community
نویسندگان
چکیده
Ecological researchers have long borrowed concepts from the theory of chemical kinetics to describe nutrient dynamics in ecosystems. Contemporary ecology, however, is in the process of creating its own suite of ideas to quantify how whole ecosystems develop. In particular, the theory of ecosystem ascendency can be applied to data on the simultaneous flows of various chemical constituents to determine which element is limiting to each species via which individual input. That is, Liebig’s law of the minimum appears a corollary to the broader description of whole-system development. Application of the method to networks of carbon, nitrogen and phosphorous flowing through the 36 major compartments of the Chesapeake Bay ecosystem reveals that, although nitrogen limits the production by most of the planktonic and benthic compartments, the nekton appear to be using phosphorus in limiting proportions. If one links together the ecosystem components via the controlling flows into each node, a new and sometimes dramatic picture of nutrient kinetics emerges. Not surprisingly, during the summer the root nutrient control on the system appears to be the recycle of nitrogen between particulate organic materials in the sediments and their attached bacteria. No coherent pattern of control is evident during the autumn turnover, whereas during winter and spring the ultimate control appears to be exerted by a feedback in the ‘microbial loop’ that involves both N and P. q 1999 Elsevier Science B.V. All rights reserved.
منابع مشابه
Oyster-Sea Nettle Interdependence and Altered Control Within the Chesapeake Bay Ecosystem
Research on the effects of declining abundances of the Eastern oyster (Crassostrea virginica) in Chesapeake Bay and other estuaries has primarily focused on the role of oysters in filtration and nutrient dynamics, and as habitat for fish or fish prey. Oysters also play a key role in providing substrate for the overwintering polyp stage of the scyphomedusa sea nettle, Chrysaora quinquecirrha, wh...
متن کاملProduction and Field Planting of Vegetative Propagules for Restoration of Redhead Grass and Sago Pondweed in Chesapeake Bay
BACKGROUND: During the last several decades, seagrasses and related submerged aquatic vegetation (SAV) have been lost from shallow waters of Chesapeake Bay (Orth and Moore 1983) and other coastal ecosystems worldwide (Short and Wyllie-Echeverria 1996). Losses of SAV beds are of particular concern because these plants tend to create rich habitat and food for animals, supporting growth of diverse...
متن کاملBacterial Dynamics in Large and Small Estuaries
We have been investigating bacterioplankton biomass and production in Chesapeake Bay for the past decade. More recently we initiated a system-level study of bacterial and DOM dynamics in the York River, Virginia, a small (100 km) subestuary of the Chesapeake Bay. In Chesapeake Bay, where water residence times are long (months), bacterial biomass and production show maxima in the middle, mesohal...
متن کاملEcosystem modeling analysis of size-structured phytoplankton dynamics in the York River estuary, Virginia (USA). I. Development of a plankton ecosystem model with explicit feedback controls and hydrodynamics
An ecosystem simulation model was developed to investigate potential mechanisms controlling the size-structured phytoplankton and nutrient dynamics in the mesohaline zone of the York River estuary. The model included 12 state variables in a unit volume (m3) describing the distribution of carbon and nutrients (nitrogen, phosphorus) in the surface mixed layer. General size-scale relationships and...
متن کاملLand Use and Salinity Drive Changes in SAV Abundance and Community Composition
Conserving and restoring submerged aquatic vegetation (SAV) are keymanagement goals for estuaries worldwide because SAV integrates many aspects of water quality and provides a wide range of ecosystem services. Management strategies are typically focused on aggregated abundance of several SAV species, because species cannot be easily distinguished in remotely sensed data. Human land use and shor...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 1999