The advent of ecosystem ecology has created great difficulties for ecologists primarily trained as biologists, since inevitably as the field grew, it absorbed components of other disciplines relatively foreign to most ecologists yet vital to the understanding of the structure and function of ecosystems. From the point of view of the biological ecologist struggling to understand the enormous complexity of the biological functions within an ecosystem, the added necessity of integrating biology with geochemis­ try, hydrology, micrometeorology, geomorphology, pedology, and applied sciences (like silviculture and land use management) often has appeared as an impossible requirement. Ecologists have frequently responded by limiting their perspective to biology with the result that the modeling of species interactions is sometimes considered as modeling ecosystems, or modeling the living fraction of the ecosystems is considered as modeling whole ecosystems. Such of course is not the case, since understanding the structure and function of ecosystems requires sound understanding of inanimate as well as animate processes and often neither can be under­ stood without the other. About 15 years ago, a view of ecology somewhat different from most then prevailing, coupled with a strong dose of naivete and a sense of exploration, lead us to believe that consideration of the inanimate side of ecosystem function rather than being just one more annoying complexity might provide exceptional advantages in the study of ecosystems. To examine this possibility, we took two steps which occurred more or less simultaneously.

When we originally published Biogeochemistry of a Forested Ecosystem in 1977, the Hubbard Brook Ecosystem Study (HBES) had been in existence for 14 years, and we included data through 1974, or a biogeo­ chemical record of 11 years. Now our continuous, long-term biogeo­ chemical records cover more than 31 years, and there have been many changes. The most notable change, however, is that three of our coauthors on the original volume are now deceased. They are deeply missed in so many ways. In spite of the longer records, different trends, and new insights, we believe that the basic concepts and approaches we presented in 1977 represent the most valuable contribution of the original edition. They are still valid and useful, particularly for an introductory study of, or course in, biogeochemistry. Our goal in this revision is to preserve these fea­ tures, correct errors, and revise or eliminate misleading or ambiguous short-term data (11 years!), while maintaining approximately the original length and the modest cost.

The advent of ecosystem ecology has created great difficulties for ecologists primarily trained as biologists, since inevitably as the field grew, it absorbed components of other disciplines relatively foreign to most ecologists yet vital to the understanding of the structure and function of ecosystems. From the point of view of the biological ecologist struggling to understand the enormous complexity of the biological functions within an ecosystem, the added necessity of integrating biology with geochemis­ try, hydrology, micrometeorology, geomorphology, pedology, and applied sciences (like silviculture and land use management) often has appeared as an impossible requirement. Ecologists have frequently responded by limiting their perspective to biology with the result that the modeling of species interactions is sometimes considered as modeling ecosystems, or modeling the living fraction of the ecosystems is considered as modeling whole ecosystems. Such of course is not the case, since understanding the structure and function of ecosystems requires sound understanding of inanimate as well as animate processes and often neither can be under­ stood without the other. About 15 years ago, a view of ecology somewhat different from most then prevailing, coupled with a strong dose of naivete and a sense of exploration, lead us to believe that consideration of the inanimate side of ecosystem function rather than being just one more annoying complexity might provide exceptional advantages in the study of ecosystems. To examine this possibility, we took two steps which occurred more or less simultaneously.

When we originally published Biogeochemistry of a Forested Ecosystem in 1977, the Hubbard Brook Ecosystem Study (HBES) had been in existence for 14 years, and we included data through 1974, or a biogeo­ chemical record of 11 years. Now our continuous, long-term biogeo­ chemical records cover more than 31 years, and there have been many changes. The most notable change, however, is that three of our coauthors on the original volume are now deceased. They are deeply missed in so many ways. In spite of the longer records, different trends, and new insights, we believe that the basic concepts and approaches we presented in 1977 represent the most valuable contribution of the original edition. They are still valid and useful, particularly for an introductory study of, or course in, biogeochemistry. Our goal in this revision is to preserve these fea­ tures, correct errors, and revise or eliminate misleading or ambiguous short-term data (11 years!), while maintaining approximately the original length and the modest cost.