In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 109, No. 18 ( 2012-05)
Abstract:
Similar application of paleoenvironmental records to many regions worldwide is possible, but there are caveats. Limitations on data accuracy and precision, irregular time series, variable spatial inferences, and unavailability of records may all constrain the transferability of the approach. Nevertheless, as global concerns turn strongly toward the impacts from climate and human activities within regions, this study demonstrates how we may use the wealth of information produced by paleoenvironmental methods more effectively to design sustainable management strategies ( 5 ). Compiling, scrutinizing, integrating, and modeling multidecadal paleoenvironmental records of ecosystem services should now be viewed as a major international scientific priority. An index for regulating services shows a decline starting in the 1970s during the period of the Cultural Revolution ( Fig. P1 ). The losses accelerated after Deng Xiaoping’s “opening-up” reforms in the 1980s and continue to the present time (2006). The decline of the index points strongly to agricultural intensification and industrial development as the main drivers of regulating service losses. Improved environmental regulation and environmental policies after the late 1980s may have partially stabilized losses of biodiversity and erosion regulating services. However, for water purification, there is strong evidence that thresholds ( 4 ) have already been transgressed. The records show clearly how the trade-off between economic growth and environmental degradation has evolved. The region has yet to reach a stage where economic development is decoupled from ecological degradation. Past success in the drive to alleviate rural poverty should be tempered against the likelihood of ecological failure in the near future. In the Chinese case study, lake sediment data derived from analyses of microfossils, geochemistry, mineral magnetism, and sediment accumulation rates give regional signals of changing biodiversity, soil stability, water quality, sediment quality, sediment regulation, and air quality for the past 200 y. Complementary data from official statistical records and climate models give regional trends for land use, population, gross domestic product, temperature, and precipitation. Following the Millennium Ecosystem Assessment Synthesis ( 3 ), we map the range of paleoenvironmental records onto the following categories of ecosystem services: “supporting (e.g., nutrient cycles),” “provisioning (e.g., food and fiber),” “regulating” (e.g., water purification), and “cultural” (e.g., recreational benefits). For subcategories, we identify or define 〉 50 representative processes or system states for which recognized types of paleoenvironmental proxy records exist. It seems that the “regulating services” category may have the greatest number of potential paleoenvironmental proxy records. Importantly, these records are often the least well monitored, especially in remote areas and developing nations. Sources of data for ecological change over the last few decades and centuries lie in natural archives, such as lake sediments. Such paleoenvironmental research has long been concerned with climate and human impacts on natural processes (e.g., ref. 2 ) but has yet to fully embrace the ecosystem service agenda that demands integration of social and ecological records. The aim of this work is to rectify this situation with a case study using paleoenvironmental and socioeconomic records from two lake catchments lying west of Nanjing in eastern China. Resources and processes provided by natural ecosystems offer numerous benefits known as ecosystem services; these services have become central to discussions about the sustainable management of natural resources ( 1 ). However, critical knowledge gaps exist in many regions worldwide, especially with regard to the dynamics of services that support and regulate ecosystems. Here we review the role of paleoenvironmental sequences to provide multidecadal information for ecosystem services, exemplified by a case study from the lower Yangtze basin. The Chinese study shows rapid losses of regulating services, especially since the 1980s, mirroring the rise in population and economic growth ( Fig. P1 ). The findings imply that land management practices are critically unsustainable.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.1118263109
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
2012
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12
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