414
Characterizing the Human Imprint on Landscapes for Ecological Assessment
tion. The land cover would be classified as some
sort of grassland, whereas the land use, at least in
the majority of this area, is for pasture and hay production. The former has direct effects on ecosystem functioning (e.g., hydrologic and biogeochemical cycling functions differently on grasslands than
forests), and the latter is driven by numerous economic, cultural, demographic, and political factors.
The rows of planted trees in the southeastern portion of the section suggest something of the history
of the site. This area, like many areas in the upper
Midwest, was logged initially during the late 19th
or early 20th century; then farming was attempted.
Now, because of the difficulty of farming the
glacial soils with a short growing season, many
sites have been planted to forest or are reverting to
forest naturally.
The impacts of the intangible boundaries on the
landscape are also evident in Figure 27.3. The ownership boundaries retain their rectilinear shape imposed during the initial survey and disposal of the
land. The parcel in the extreme southwestern corner of the section is a l6-ha (40-acre) parcel, or
one-quarter of a quarter-section. In an attempt to
reduce the amount of land subdivision in Michigan, the state legislature passed the Subdivision
Control Act (or SCA) in 1967. To avoid paying
high fees for subdividing their land, land owners
could not divide and sell more than four parcels of
4 ha (10 acres) or less in a span of 10 years. This
has led to proliferation of parcels that are just over
4 ha throughout rural Michigan (Norgaard, 1994),
like the four narrow parcels found along the northern edge of this section. The importance of boundary shapes for ecosystem structure is illustrated by
the rectilinear boundaries that follow property
boundaries of the plantation in the southeast corner of the section. Also, the tonal variation between
the two grassland parcels in the northwest comer
of the section suggests that, although the land cover
class is the same, the degree and type of management have been different. Finally, a utility corridor
right-of-way, which is not explicitly owned by the
utility company, is evident as a swath through the
plantation forest on the southern edge of the section.
27.4 Conclusions
This chapter has outlined a number of tangible and
intangible human elements that are present in most
ecosystems and that should be considered in a complete ecological assessment. Not all these elements
will be of importance in every situation, but taken
as a whole they can dramatically affect ecosystem
history, function, and potential. Although it is
tempting to treat human activity as external to the
functioning of natural ecosystems, the interrelationships among the value humans place on ecosystems, the goods and services that they derive from
them, and natural processes dictate that the human
dimension be understood as evolving with the ecological system.
A variety of anthropogenic issues have been presented that should be considered in an ecological
assessment. Two important common issues to the
characterization of many of these elements are spatial scale and the temporal nature of these elements.
The issue of spatial scale, although often determined by the availability of data, affects our ability to characterize various processes. Although of
more importance to some of the elements than others, the dynamic nature of the human dimension requires vigilance in the obtaining and maintaining
of data.
Integrating the human dimension within an ecological assessment poses challenges to both our
ability to characterize the essential elements and to
understand their significance. Given the importance of human activities in driving, constraining,
and redirecting ecological function, it is imperative
that these challenges be met.
27.5 References
Adams, J. B.; Sabol, D. E.; Kapos, V.; Filho, R A.;
Roberts, D. A.; Smith, M. 0.; Gillespie, A. R 1995.
Classification of multispectral images based on fractions of endmembers: application to land-cover change
in the Brazilian Amazon. Remote Sens. Environ. 52:
137-154.
Anderson, J. R; Hardy, E. E.; Roach, J. T.; Witmer, R
E. 1976. A land use and land cover classification system for use with remote sensor data. Geological Survey Professional Paper 964. Washington, DC: U.S.
Govt. Printing Office.
Brown, D. G.; Duh, J. D.; Drzyzga, S. 2000a. Estimating error in an analysis of forest fragmentation change
using North American Landscape Characterization
Data. Remote Sens Environ. 71: 106-117.
Brown, D. G.; Pijanowski, B. c.; Duh, J. D. 2000b. Modeling the relationships between land-use and landcover on private lands in the Upper Midwest, USA.
J Environ Manage. 59:247-263.
Brown, D. G.; Vasievich, J. M. 1996. A study of land
ownership fragmentation in the Upper Midwest. In:
Proceedings, GIS/LIS '96 Conference, November
19-21, 1996, Denver, CO. Bethesda, MD: Amer. Soc.
Photogramm. Remote Sens.: 1199-1209.
Dobson, J. E.; Bright, E. A.; Ferguson, R L.; Field, D. W.;
Characterizing the Human Imprint on Landscapes for Ecological Assessment
tion. The land cover would be classified as some
sort of grassland, whereas the land use, at least in
the majority of this area, is for pasture and hay production. The former has direct effects on ecosystem functioning (e.g., hydrologic and biogeochemical cycling functions differently on grasslands than
forests), and the latter is driven by numerous economic, cultural, demographic, and political factors.
The rows of planted trees in the southeastern portion of the section suggest something of the history
of the site. This area, like many areas in the upper
Midwest, was logged initially during the late 19th
or early 20th century; then farming was attempted.
Now, because of the difficulty of farming the
glacial soils with a short growing season, many
sites have been planted to forest or are reverting to
forest naturally.
The impacts of the intangible boundaries on the
landscape are also evident in Figure 27.3. The ownership boundaries retain their rectilinear shape imposed during the initial survey and disposal of the
land. The parcel in the extreme southwestern corner of the section is a l6-ha (40-acre) parcel, or
one-quarter of a quarter-section. In an attempt to
reduce the amount of land subdivision in Michigan, the state legislature passed the Subdivision
Control Act (or SCA) in 1967. To avoid paying
high fees for subdividing their land, land owners
could not divide and sell more than four parcels of
4 ha (10 acres) or less in a span of 10 years. This
has led to proliferation of parcels that are just over
4 ha throughout rural Michigan (Norgaard, 1994),
like the four narrow parcels found along the northern edge of this section. The importance of boundary shapes for ecosystem structure is illustrated by
the rectilinear boundaries that follow property
boundaries of the plantation in the southeast corner of the section. Also, the tonal variation between
the two grassland parcels in the northwest comer
of the section suggests that, although the land cover
class is the same, the degree and type of management have been different. Finally, a utility corridor
right-of-way, which is not explicitly owned by the
utility company, is evident as a swath through the
plantation forest on the southern edge of the section.
27.4 Conclusions
This chapter has outlined a number of tangible and
intangible human elements that are present in most
ecosystems and that should be considered in a complete ecological assessment. Not all these elements
will be of importance in every situation, but taken
as a whole they can dramatically affect ecosystem
history, function, and potential. Although it is
tempting to treat human activity as external to the
functioning of natural ecosystems, the interrelationships among the value humans place on ecosystems, the goods and services that they derive from
them, and natural processes dictate that the human
dimension be understood as evolving with the ecological system.
A variety of anthropogenic issues have been presented that should be considered in an ecological
assessment. Two important common issues to the
characterization of many of these elements are spatial scale and the temporal nature of these elements.
The issue of spatial scale, although often determined by the availability of data, affects our ability to characterize various processes. Although of
more importance to some of the elements than others, the dynamic nature of the human dimension requires vigilance in the obtaining and maintaining
of data.
Integrating the human dimension within an ecological assessment poses challenges to both our
ability to characterize the essential elements and to
understand their significance. Given the importance of human activities in driving, constraining,
and redirecting ecological function, it is imperative
that these challenges be met.
27.5 References
Adams, J. B.; Sabol, D. E.; Kapos, V.; Filho, R A.;
Roberts, D. A.; Smith, M. 0.; Gillespie, A. R 1995.
Classification of multispectral images based on fractions of endmembers: application to land-cover change
in the Brazilian Amazon. Remote Sens. Environ. 52:
137-154.
Anderson, J. R; Hardy, E. E.; Roach, J. T.; Witmer, R
E. 1976. A land use and land cover classification system for use with remote sensor data. Geological Survey Professional Paper 964. Washington, DC: U.S.
Govt. Printing Office.
Brown, D. G.; Duh, J. D.; Drzyzga, S. 2000a. Estimating error in an analysis of forest fragmentation change
using North American Landscape Characterization
Data. Remote Sens Environ. 71: 106-117.
Brown, D. G.; Pijanowski, B. c.; Duh, J. D. 2000b. Modeling the relationships between land-use and landcover on private lands in the Upper Midwest, USA.
J Environ Manage. 59:247-263.
Brown, D. G.; Vasievich, J. M. 1996. A study of land
ownership fragmentation in the Upper Midwest. In:
Proceedings, GIS/LIS '96 Conference, November
19-21, 1996, Denver, CO. Bethesda, MD: Amer. Soc.
Photogramm. Remote Sens.: 1199-1209.
Dobson, J. E.; Bright, E. A.; Ferguson, R L.; Field, D. W.;