19. Afterword
385
standing not only depends on the involvement of scientists from different
disciplines but requires systems to be examined with shared paradigms
and with common approaches that integrate the findings into both quantitative and qualitative frameworks. Scientific studies must become fully
integrated if they are going to address fully the complexity of interactions
between physical environments and biological communities and to predict
the effects of human influences of ecosystems. One of the major challenges
in the full integration of disciplines arises from the need to link processes
at different scales, because biota respond at local scales, while most
physical processes are local manifestations of much larger-scale
interactions.
Multiscale Approaches
One theme that frequently arises in this volume relates to the importance
of scale in the analysis and understanding of ecosystems. Variability
occurs at local scales with different forest types along gradients of moisture
and nutrient availability or biotic responses to disturbances at all scales.
Variations in forest structure and function lead to different responses of
the forest to the climate and, in turn, different feedbacks from the forest
to the atmosphere. On the one hand, forest ecosystems are affected by
fragmentation introduced through human activities at the landscape level;
on the other hand , they are influenced by continental and ocean basinscale atmospheric controls arising from sea surface temperature anomalies.
Large-scale climatic fluctuations also lead to local extremes in runoff ,
affect the intensity of geochemical cycling, and influence the development
and functioning of plant communities. Scale effects need to be accounted
for in the collection and evaluation of field data. Data obtained by remote
sensing represent areal averages that mayor may not be related to the
biological characteristics observed on the earth's surface. Furthermore,
these data do not include the three dimensional effects of vegetation
structure, a key parameter for forest and wildlife relationships.
Variability also affects larger scales. Although logging is site specific, its
effects on water chemistry and erosion may occur a number of kilometers
away from the place where it is taking place. Local emissions of air
pollutants to the atmosphere may be carried by the prevailing winds to
sites tens and even hundreds of kilometers away. Logging dispersed over
a large enough area will create patches in the forest that lead to local
mesoscale circulation patterns that can affect the local distribution of
precipitation and at the same time can disrupt the continuity of natural
habitat for animals and binds.
The functioning of natural systems involves the ongoing dynamic
scaling up of local effects and scaling down of larger-scale atmospheric
effects, which combine to produce complex ecosystem behavior. More
385
standing not only depends on the involvement of scientists from different
disciplines but requires systems to be examined with shared paradigms
and with common approaches that integrate the findings into both quantitative and qualitative frameworks. Scientific studies must become fully
integrated if they are going to address fully the complexity of interactions
between physical environments and biological communities and to predict
the effects of human influences of ecosystems. One of the major challenges
in the full integration of disciplines arises from the need to link processes
at different scales, because biota respond at local scales, while most
physical processes are local manifestations of much larger-scale
interactions.
Multiscale Approaches
One theme that frequently arises in this volume relates to the importance
of scale in the analysis and understanding of ecosystems. Variability
occurs at local scales with different forest types along gradients of moisture
and nutrient availability or biotic responses to disturbances at all scales.
Variations in forest structure and function lead to different responses of
the forest to the climate and, in turn, different feedbacks from the forest
to the atmosphere. On the one hand, forest ecosystems are affected by
fragmentation introduced through human activities at the landscape level;
on the other hand , they are influenced by continental and ocean basinscale atmospheric controls arising from sea surface temperature anomalies.
Large-scale climatic fluctuations also lead to local extremes in runoff ,
affect the intensity of geochemical cycling, and influence the development
and functioning of plant communities. Scale effects need to be accounted
for in the collection and evaluation of field data. Data obtained by remote
sensing represent areal averages that mayor may not be related to the
biological characteristics observed on the earth's surface. Furthermore,
these data do not include the three dimensional effects of vegetation
structure, a key parameter for forest and wildlife relationships.
Variability also affects larger scales. Although logging is site specific, its
effects on water chemistry and erosion may occur a number of kilometers
away from the place where it is taking place. Local emissions of air
pollutants to the atmosphere may be carried by the prevailing winds to
sites tens and even hundreds of kilometers away. Logging dispersed over
a large enough area will create patches in the forest that lead to local
mesoscale circulation patterns that can affect the local distribution of
precipitation and at the same time can disrupt the continuity of natural
habitat for animals and binds.
The functioning of natural systems involves the ongoing dynamic
scaling up of local effects and scaling down of larger-scale atmospheric
effects, which combine to produce complex ecosystem behavior. More