prehending the implications of this disposal downstream. The implications of this are more and more evident in the widespread cultural eutrophication of rivers and lakes. Attempts to understand these problems have been based upon information pieced together from separate (independent) aquatic and terrestrial studies. This ignores important linkages, is inadequate, and shows the need for a comprehensive understanding of the intricate and complicated interactions between land and water. The purpose of this paper, then, is to consider some of the ecological interactions and linkages that occur between

https://www.jstor.org/stable/pdfplus/1296852.pdf

Linkages between Terrestrial and Aquatic Ecosystems

Vitousek & Reiners (158) have suggested that change in net ecosystem production is a major determinant of the balance between inputs and out­ puts of elements in terrestrial ecosystems. They argued that in the course of primary succession element outputs are initially relatively high (approx­ imating inputs), that they then drop to a minimum because of element accumulation in biomass and detritus when net ecosystem production is highest, and that eventually output rates rise again approximately to equal inputs in late succession when net ecosystem production approaches zero (Figure 1). In most cases of secondary succession, net ecosystem production is negative immediately following disturbance, and in such cases output rates can exceed input rates. The probable importance of change in net ecosystem production is supported in particular by observations of higher element outputs from later successional ecosystems (22, 90, 1'57-159) and

The regulation of chemical budgets over the course of terrestrial ecosystem succession [Forested watersheds].

https://www.jstor.org/stable/info/2096785

The regulation of chemical budgets over the course of terrestrial ecosystem succession

Analyses of multiple sediment cores from Mirror Lake, New Hampshire, dated by 14C and pollen, show that between 14,000 and 11,000 B.P. silts and sands were deposited over 85% of the basin. After 11,000 B.P. organic-rich sediments were focused into the deeper parts of the basin, and no sediment accumulated in water <5 m deep. . Late-glacial particulate inorganic inputs were 33 times greater than modern losses from forested watersheds at Hubbard Brook. After trees became established, inorganic inputs fell sharply to modern levels. Late-glacial organic inputs were a half the average during the last 11,000 years. At four of the sites studied, accumulation rates reached a maximum between 7000 and 4000 B.P. The precise date varies from site to site, suggesting that it would be misleading to link peak accumulation in a single core to events in the watershed. After 4000 B.P. organic sediment accumulation rates declined at all four sites. Parallel declines in accumulation rates of both pollen and inorganic sediments suggest that this decline is due to the process of sediment focusing rather than to a change in decomposition rates or in organic inputs related to autochthonous or allochthonous primary production.

https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.1982.27.1.0137

Sediment focusing in Mirror Lake, New Hampshire1

SUMMARY. 

1
The factors that control the concentrations of pigments in lake sediments are examined using data from (i) transects across lake basins, (ii) surface samples from logographic and atrophic lakes, and (iii) two 210Pb-dated short cores. Methods for the rapid non-chromatographic analysis of percent native chlorophyll and the blue-green algal pigments oscillaxanthin and myxoxanthophyll are described.

2
The concentrations of chlorophyll derivatives, total arytenoids, oscillaxanthin and myxoxanthophyll, and percent native chlorophyll, are higher under conditions along the transects favorable for preservation. Chlorophyll degrades at about the same rate as total carotenoids, and oscillaxanthin degrades at about the same rate as myxoxanthophyll. Therefore, both the ratio of chlorophyll to arytenoids (CD/TC) and the ratio of oscillaxanthin to myxoxanthophyll (OSC/MYX) are mostly determined by the quality of autochthonous production rather than by preservation conditions.

3
CD/TC values are higher in logographic lakes than in atrophic lakes, apparently as a result of differences in production of the two pigment types. Calculations show that CD/TC shifts in these two cores cannot be a record of the allochthonous-autochthonous Baltic in the systems. Instead, the CD/TC values shift with large changes in the kinds of plants dominating primary production.

4
The stratigraphy of percent native chlorophyll appears to record the hypohmnetic oxygen concentrations at the time of deposition.

5
No obvious reason exists why a eutrophic lake should produce more pigment per gram organic matter than should an oligotrophic lake. However, several correlated mechanisms tend to produce higher sedimentary pigment concentrations in eutrophic lakes. Most of these mechanisms, such as hypolimnetic oxygen consumption, indirectly translate greater primary productivity into greater sedimentary pigment concentration. Therefore, pigment concentrations are sometimes misleading, and pigment accumulation rate may be a better indicator of past primary production.

Measurement and interpretation of sedimentary pigments

During the late glacial and postglacial the productivity of Berry Pond in Berkshire County, Massachusetts, underwent a number of significant oscillations. This is suggested by data on sedimentary chlorophyll degradation products, diatoms, and Cladocera. The productivity changes were. apparently controlled by changes in weathering, terrestrial vegetation in the watershed, litter production, and runoff. There are associated changes in cladoceran community structure.

http://science.sciencemag.org/content/sci/181/4101/744.full.pdf

Claudia B. Douglass

Papers

Late Glacial and Postglacial Productivity Changes in a New England Pond