Environmental Engineering Reference
In-Depth Information
Vitousek et al. 1989
). In doing so, we began to identify the influences of land use change
in the tropics on greenhouse gas emissions (
Matson et al. 1987, 1990; Matson and Vitousek
1990
), and the role of agricultural fertilization in driving the increase in nitrous oxide
(
Matson et al. 1996
), the causes of which were in debate at that time. We explored the bio-
geochemical processes that regulated fluxes within and beyond tropical forest and agricul-
tural ecosystems, and identified where and how management influenced the processes.
And we helped articulate the global dimensions of changes in nitrogen, characterizing the
enormous and rapid change driven largely by the use of industrial fertilizers (
Vitousek
and Matson 1993
) and the consequences of that change for the global system. Altogether,
it was an exciting time for ecosystem science, specifically biogeochemistry and global
change science.
At some point in the early 1990s, our involvement in tracking change in the global nitro-
gen cycle and solving the puzzle of the increased nitrous oxide concentrations in the atmo-
sphere moved beyond academic fascination: My view of the issues changed from “this is so
(intellectually) fun” to “this is scary!” I began to want not just to study and understand and
identify the causes and consequences of global changes, but to help do something about
them. If land use change and fertilizer use were having significant impacts on the global
atmosphere, climate, and species and ecosystems, what could we do about them?
In 1992, Roz Naylor, an economist at Stanford University, and I organized a session for
the Aspen Global Change Institute called “Food, Conservation, and Environment: Is
Compromise Possible?” Bringing together ecologists, agronomists, economists, geogra-
phers, atmospheric scientists, and others, we asked, among other things, how we might
join forces to not just study change, but to develop approaches that would allow food pro-
duction and other land use to proceed while reducing negative impacts on ecosystems
and the environment. One outcome of that set of discussions was a rough research plan
that eventually launched the Yaqui Valley study.
THE YAQUI VALLEY CASE STUDY
In 1993, Roz Naylor, Ivan Ortiz-Monasterio (an agronomist working for the
International Maize and Wheat Improvement Center (CIMMYT) in Sonora, Mexico), and
I initiated a project centered on fertilizer use and nitrogen flows in the intensive wheat
agricultural systems of the Yaqui Valley to (1) understand how and why farmers were
managing their intensive cropping systems; (2) identify the resulting consequences for
land, water, and atmosphere; and (3) also evaluate alternative management practices that
could make sense economically, environmentally, and agronomically. From the beginning,
our studies of fertilizer management straddled the worlds of global environmental change
on the one hand and international agronomic systems and policies on the other. Over
time, our focus evolved to include more cross-cutting themes such as vulnerability and
knowledge systems issues, themes that are now emerging as crucial questions in sustain-
ability science (
Clark 2007
). Likewise, our early innovation—the purposeful and at that
time quite unusual focus on the integrated ecological
agronomic system—
evolved over time to a full-fledged focus on sustainability of human
economic
environment
systems.
