Introduction. Methods in Ecosystem Science: Progress, Tradeoffs, and Limitations
3
from the real value. For example, when estimating
primary production from a time series of total biomass versus from time series of individual species
biomass, the latter yields valuable information
about the behavior of individual species but an estimate of total production that is farther from the
real value than if just total values were used (see
Chapters 2, 4, and 18 for examples of errors associated with aggregation). Similarly, nutrient estimates at the mouth of a river yield better estimates
of the biogeochemical behavior of the watershed
than could have been obtained by laboriously measuring individual units in the watershed (Howarth
et al. 1996). When the purpose of the study is the
accurate estimate, then integrating measurements at
the questions' scale are usually preferred. In contrast, when the main purpose is mechanistic understanding of ecosystem processes, detail estimates at
finer scales than the level of interest are preferred.
Ecosystem science is complex and interacts with
many other disciplines, such as atmospheric science, soil science, plant and animal physiology, as
well as microbiology, zoology, and botany. The nature of ecosystem questions calls for such interdisciplinary work. Consequently, ecosystem studies
incorporate pieces of methods from other disciplines and adapt them to satisfy ecosystem questions, which have their own scales and their own
emphasis on interactions. The multi scale nature of
ecosystem science, the wealth of interactions with
other disciplines, the breadth of ecosystem studies,
and the relatively recent development of its major
concepts may explain the lack of a book to date that
summarizes the methods used in ecosystem
science.
One of the strengths of ecosystem science is the
focus on the interactions among levels and between
biotic and abiotic factors. This same strength results
in a challenge to organize a methods book because
most techniques examine the patterns and dynamics
of more than one factor. Similarly, experimental
manipulation of ecosystems that alter one part of
the ecosystem frequently affect many other compartments and processes. This book is organized in
four parts: the first encompasses methods related
to carbon and energy dynamics, the second discusses those related to water and nutrient dynamics,
the third describes experimental manipulations of
abiotic and biotic factors, and the fourth discusses
tools to synthesize our understanding about
ecosystems.
References
Allen, T.; Starr, T. Hierarchy: Perspectivesfor Ecological
Complexity. Chicago: Univ. Chicago Pr.; 1982.
Howarth, R.; Billen, G.; Swaney, D.; Townsend, A.; Jaworski, N.; Lajtha, K.; Downing, J.; Elmgren, R.; Caraco, N.; Jordan, T. et al. Regional nitrogen budgets
and riverine N & P fluxes for the drainages to the
North Atlantic Ocean: Natural and human influences.
Biogeochemistry: 35:75-139; 1996.
Odum, E. Fundamentals of Ecology. Philadelphia: Saunders; 1959.
O'Neill, R.; DeAngelis, D.; Waide, J.; Allen, T. A Hierarchical Concept of Ecosystems. Princeton, NJ:
Princeton Univ. Pr.; 1986.
Sala, O.E.; Parton, w.J.; Lauenroth, w.K.; Joyce, L.A.
Primary production of the central grassland region of
the United States. Ecology 69:40--45; 1988.
3
from the real value. For example, when estimating
primary production from a time series of total biomass versus from time series of individual species
biomass, the latter yields valuable information
about the behavior of individual species but an estimate of total production that is farther from the
real value than if just total values were used (see
Chapters 2, 4, and 18 for examples of errors associated with aggregation). Similarly, nutrient estimates at the mouth of a river yield better estimates
of the biogeochemical behavior of the watershed
than could have been obtained by laboriously measuring individual units in the watershed (Howarth
et al. 1996). When the purpose of the study is the
accurate estimate, then integrating measurements at
the questions' scale are usually preferred. In contrast, when the main purpose is mechanistic understanding of ecosystem processes, detail estimates at
finer scales than the level of interest are preferred.
Ecosystem science is complex and interacts with
many other disciplines, such as atmospheric science, soil science, plant and animal physiology, as
well as microbiology, zoology, and botany. The nature of ecosystem questions calls for such interdisciplinary work. Consequently, ecosystem studies
incorporate pieces of methods from other disciplines and adapt them to satisfy ecosystem questions, which have their own scales and their own
emphasis on interactions. The multi scale nature of
ecosystem science, the wealth of interactions with
other disciplines, the breadth of ecosystem studies,
and the relatively recent development of its major
concepts may explain the lack of a book to date that
summarizes the methods used in ecosystem
science.
One of the strengths of ecosystem science is the
focus on the interactions among levels and between
biotic and abiotic factors. This same strength results
in a challenge to organize a methods book because
most techniques examine the patterns and dynamics
of more than one factor. Similarly, experimental
manipulation of ecosystems that alter one part of
the ecosystem frequently affect many other compartments and processes. This book is organized in
four parts: the first encompasses methods related
to carbon and energy dynamics, the second discusses those related to water and nutrient dynamics,
the third describes experimental manipulations of
abiotic and biotic factors, and the fourth discusses
tools to synthesize our understanding about
ecosystems.
References
Allen, T.; Starr, T. Hierarchy: Perspectivesfor Ecological
Complexity. Chicago: Univ. Chicago Pr.; 1982.
Howarth, R.; Billen, G.; Swaney, D.; Townsend, A.; Jaworski, N.; Lajtha, K.; Downing, J.; Elmgren, R.; Caraco, N.; Jordan, T. et al. Regional nitrogen budgets
and riverine N & P fluxes for the drainages to the
North Atlantic Ocean: Natural and human influences.
Biogeochemistry: 35:75-139; 1996.
Odum, E. Fundamentals of Ecology. Philadelphia: Saunders; 1959.
O'Neill, R.; DeAngelis, D.; Waide, J.; Allen, T. A Hierarchical Concept of Ecosystems. Princeton, NJ:
Princeton Univ. Pr.; 1986.
Sala, O.E.; Parton, w.J.; Lauenroth, w.K.; Joyce, L.A.
Primary production of the central grassland region of
the United States. Ecology 69:40--45; 1988.