Amanda H. Schmidt

Early evidence for the use of wheat and barley as staple crops on the margins of the Tibetan Plateau

Significance Adapting agricultural systems to the high-altitude environment of the Tibetan Plateau has long been considered a major challenge for farmers. It has been asserted previously that the ecological characteristics of wheat and barley delayed their spread into East Asia. We argue instead that the ability of these crops to tolerate frost and their low heat requirements facilitated their spread into the high-altitude margins of western China. Following their introduction to this region, these crops rapidly replaced Chinese millets that could not adapt to the cooler temperatures of post-Holocene climatic optimum East Asia. We present data from the eastern Tibetan Plateau demonstrating that wheat and barley rapidly became staple crops shortly after their introduction. We report directly dated evidence from circa 1400 calibrated years (cal) B.C. for the early use of wheat, barley, and flax as staple crops on the borders of the Tibetan Plateau. During recent years, an increasing amount of data from the Tibetan Plateau and its margins shows that a transition from millets to wheat and barley agriculture took place during the second millennium B.C. Using thermal niche modeling, we refute previous assertions that the ecological characteristics of wheat and barley delayed their spread into East Asia. Rather, we demonstrate that the ability of these crops to tolerate frost and their low growing degree-day requirements facilitated their spread into the high-altitude margins of western China. Following their introduction to this region, these crops rapidly replaced Chinese millets and became the staple crops that still characterize agriculture in this area today.

A New Model for Training Graduate Students to Conduct Interdisciplinary, Interorganizational, and International Research

Environmental challenges are often global in scope and require solutions that integrate knowledge across disciplines, cultures, and organizations. Solutions to these challenges will come from diverse teams and not from individuals or single academic disciplines; therefore, graduate students must be trained to work in these diverse teams. In this article, we review the literature on training graduate students to cross these borders. We then present a National Science Foundation Integrative Graduate Education and Research Traineeship Program at the University of Washington as a model of border-crossing graduate training focused on interdisciplinary, international, and interorganizational (I3) collaborations on environmental challenges. Finally, we offer recommendations from this program to those considering similar I3 training programs, including strategies for maintaining faculty buy-in, for scaffolding student training to cross borders, and for conducting focused group trips that give the students structured experience crossing all three borders simultaneously.

Demonstrating urban pollution using toxic metals of road dust and roadside soil in Chengdu, southwestern China

As one of the largest economical hubs in southwestern China, Chengdu is witnessing fast urbanization characterized by rapid urban sprawl, population growth, infrastructural construction, and motorization. However, this rapid urbanization may lead to environmental degradation, placing human health at risk. In this study, toxic metals in road dust and roadside soil are used as proxies to illustrate environmental changes of Chengdu. In August 2009, 133 dust and 132 soil samples were collected from the first, second and third ring roads, along which areas have urbanized for different times. By means of a portable X-ray fluorescence analyzer, concentrations of Pb, Zn and Cu in the samples were determined. The results indicate that the concentrations and contamination levels of Pb, Zn and Cu in dust declined significantly from the first to the third ring roads, paralleling the decreasing trends in traffic and building densities from the first to the third ring roads. However, concentrations of the three elements in roadside soil were relatively stable among the roads. These data may suggest that the metals in road dust can be used as proxies to demonstrate environmental degradation during the urbanization of Chengdu, while concentrations of the metals in roadside soil are affected more by natural factors (e.g., background concentrations, precipitation, and distance to road) than by anthropogenic factors (e.g., traffic and building densities). Furthermore, compared to Pb concentrations measured in the 1990s, Pb concentrations in road dust have been reduced most likely owing to the exclusion of leaded petrol since 2000. Similar situations may be found in many other cities that are experiencing fast urbanization.

Is the Returning Farmland to Forest Program a Success? Three Case Studies from Sichuan

Chinas tuigeng huanlin or “Returning Farmland to Forest” (RFFP) program has been widely praised as the worlds largest and most successful payment for ecosystem services program, as well as a major contributor to Chinas dramatic increase in forest cover from perhaps as low as 8% in 1960 to about 21% today. By compensating rural households for the conversion of marginal farmland to forestland and financing the afforestation of barren mountainsides, the program, in addition to expanding forestland, aims to reduce soil erosion and alleviate poverty. This paper presents qualitative and quantitative studies conducted on the local implementation of RFFP in three diverse townships in Sichuan. We find the actual results to be more mixed than the official figures would indicate. Though there have been some positive results, we identify problems with site and species selection, compensation for land taken out of cultivation, shift of labor to off-farm activities, and monitoring of replanted sites, which challenge the ecological and economic impacts of these programs and reveal much of the effort of the program has been misdirected. We suggest that efforts are misplaced because of the top-down, panacea nature of the program, which in turn is a feature of Chinese bureaucratic management.

The Question of Communist Land Degradation: New Evidence from Local Erosion and Basin-Wide Sediment Yield in Southwest China and Southeast Tibet

Chinese Communist Party doctrine promotes the Confucian belief that the environment should be subjugated to mans will, and modern policies have been identified as compounding environmental degradation caused by historical agricultural practices. In this context, social scientists report massive increases in erosion throughout China, an assertion variously supported and questioned by daily sediment yield data in the Yellow and Yangtze River basins. In this study we used up to twenty-seven-year records of daily sediment yield for stations in southwest China and southeast Tibet to calculate annual and average annual sediment yields over the period of record. We also calculated coefficients for annual sediment rating curves as a way to determine interannual changes in sediment transport, that are insensitive to variations in rainfall. We found no systematic changes in annual sediment yield or rating curve parameters through time. Sediment yield is correlated with upstream area, mean annual rainfall, fraction of land under cultivation, population density, and mean monsoon rainfall but not with mean local relief, basin relief ratio, fraction of cropland from satellite data, or drainage density. Variability in mean annual sediment yield decreases as basin area increases, suggesting that larger basins store sediment more effectively and buffer against extreme events. We propose that anthropogenic changes to sediment yields have been smaller than the magnitude of interannual variability and might be comparable to the effect of the regional rainfall gradient across the basins. In basins with substantial anthropogenic activity, sediment storage might be affecting any signal we might otherwise see.

Combining Spectral with Texture Features into Object- oriented Classification in Mountainous Terrain Using Advanced Land Observing Satellite Image

Most existing classification studies use spectral information and those were adequate for cities or plains. This paper explores classification method suitable for the ALOS (Advanced Land Observing Satellite) in mountainous terrain. Mountainous terrain mapping using ALOS image faces numerous challenges. These include spectral confusion with other land cover features, topographic effects on spectral signatures (such as shadow). At first, topographic radiometric correction was carried out to remove the illumination effects of topography. In addition to spectral features, texture features were used to assist classification in this paper. And texture features extracted based on GLCM (Gray Level Co-occurrence Matrix) were not only used for segmentation, but also used for building rules. The performance of the method was evaluated and compared with Maximum Likelihood Classification (MLC). Results showed that the object-oriented method integrating spectral and texture features has achieved overall accuracy of 85.73% with a kappa coefficient of 0.824, which is 13.48% and 0.145 respectively higher than that got by MLC method. It indicated that texture features can significantly improve overall accuracy, kappa coefficient, and the classification precision of existing spectrum confusion features. Object-oriented method Integrating spectral and texture features is suitable for land use extraction of ALOS image in mountainous terrain.

Influence of human pressure on forest resources and productivity at stand and tree scales: The case study of Yunnan pine in SW China

This paper examines human impact on stands and individual trees of Pinus yunnanensis growing near the small mountain villages of Pianshui and Yangjuan in southwestern Sichuan Province, China. In an effort to assess whether use of these forests was sustainable, we examined the effects of human use in two ways. First, we directly measured the effect of cutting branches, for fuel and fodder, on tree growth. We hypothesized that branch cutting would negatively impact tree growth. We established 12 plots on four hills and compared 14 pairs of trees, one tree in each pair with an apparently full crown and the other with a considerable portion of the crown removed. Second, we assessed stand and tree properties over a 500 m elevation gradient above the villages where we hypothesized that as elevation increases, stand and tree properties should show fewer human impacts. Although extensive branch cutting reduced the live crown, tree height and diameter, compensatory processes likely enabled trees to recover and to add basal area increments (BAIs) similar to those added by trees with full crowns. Trees and stands close to villages showed less growth and lower basal areas, respectively, than stands and trees at intermediate or distant elevations from villages. Areas relatively close to the villages showed considerable effects of human-related disturbances such as branch cutting, grazing, tree and shrub removal, losses of litter, and human and animal trails. Such areas had increased soil erosion and often loss of the ‘A’ horizon. Stands close to villages had younger trees, lower stand basal areas, smaller basal area increments, and more stumps. Our results suggest an increasingly vulnerable interface between occupants of these two villages and their surrounding forests.

Unintended Side Effects of Conservation: A Case Study of Changing Land Use in Jiuzhaigou, Sichuan, China

Toward the goals of returning the landscape of Jiuzhaigou National Nature Reserve to a perceived “natural” state and protecting the environment, the Reserve in 1998–2002 implemented forest preservation policies that included restrictions on forestry, agriculture, and animal herding practiced by resident Tibetans. To document the effects of these land use changes on landscape diversity and on human vulnerability to natural hazards, we mapped and characterized topographic parameters of anthropogenic treeless areas from 1973, 2004, and 2013 satellite images. Results showed that, in addition to a previously documented overall loss of cleared land, the distribution of treeless area elevation, aspect, and slope has changed. In 1973, treeless areas were distributed approximately uniformly across all elevations and a wide range of slopes, but now they are concentrated on relatively flat slopes in the valley bottoms (∼2400 m) and high, subalpine elevations (∼3800 m). These changes are decreasing the topographic diversity of landscapes people use and likely also decreasing the biodiversity of the Reserve, where plant communities are highly stratified based on both elevation and aspect. In addition, many 1973 treeless areas were located on deep-seated landslides, while many 2004 and 2013 treeless areas were located on landslide deposits and alluvial fans, suggesting that relocation may not be reducing the risk of natural hazards for residents. These effects combine with the previously documented decline in overall area of montane meadows and associated losses to cultural heritage, ecosystem services, and biodiversity.