Molly H. Polk

Dr. Molly H. Polk

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Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2017 in Applied Geography
Verified
Journal Article
Closed access
MPMolly H. Polk
Molly H. Polk
KYKenneth Young
Kenneth Young
Michel BaraerMichel Baraer
Michel Baraer
BMBryan G. Mark
Bryan G. Mark
JMJeffrey M. McKenzie
Jeffrey M. McKenzie
MCMark Carey
Mark Carey

10 March 2021 in Land
Verified
Journal Article
Open access
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Lindsey CarteLindsey Carte
Lindsey Carte
Alvaro HofflingerAlvaro Hofflinger
Alvaro Hofflinger
MPMolly H. Polk
Molly H. Polk
Chile has embraced the expansion of monoculture forest plantations of exotic Monterey pine and eucalyptus as part of its development strategy. While forestry is considered financially successful and meets sustainability objectives, the increase in forest plantations across southern Chile has received harsh critiques for exacerbating conflict over Indigenous land rights, producing negative environmental outcomes, and increasing poverty and inequality. There are also claims that forest plantation expansion has led to an abandonment of the countryside. Migration is viewed as a result of the socioeconomic challenges that forest plantations produce at the local level; however, the linkages have not been explored. We examine the linkages between forest plantations and migration through two questions: Is there a relationship between forest plantation cover change and out-migration from rural areas? If so, what are the factors that explain this process? We use a difference-in-differences method analyzing panel data from the Chilean census and from CONAF, the Chilean National Forest Corporation, complemented by interviews, mapping workshops, and focus groups to answer these questions. Results indicate a statistically significant relationship between expanding forest plantations and population decline in rural areas. Qualitative data show that this expansion led to displacement of residents, declines in employment opportunities, and agriculture difficulties.

1 November 2016 in Annals of the American Association of Geographers
Verified
Journal Article
Closed access
KYKenneth Young
Kenneth Young
APAlexandra G. Ponette-González
Alexandra G. Ponette-González
MPMolly H. Polk
Molly H. Polk
JLJennifer K. Lipton
Jennifer K. Lipton
Examination of the dynamism of snowlines and treelines could provide insights into environmental change processes affecting land cover in the tropical Andes Mountains. Further, land cover at these ecotones represents a powerful lens through which to monitor and understand ecological processes across biophysical gradients while acknowledging their socioenvironmental dimensions. To illustrate this approach, we draw on recent research from two sites in the high tropical Andes where, at the regional scale, land cover assessments document retreating glaciers and changing amounts of forest cover, even though steep topographic gradients impose spatial shifts at much finer scales. Our results show that heterogeneous patterns of glacier recession open up new ecological spaces for plant colonization, potentially forming new grasslands, shrublands, and wetlands. In addition, treeline shifts are tied to changes in woody plant dominance, which can vary in rate and pattern as a result of aspect, past land use, and current livelihoods. We suggest that the telecoupling of regional and global biophysical and socioeconomic drivers of land use and land cover change to specific landscape combinations of elevation, aspect, and slope position might explain much of the spatial heterogeneity that characterizes landscape stasis and flux in mountains.

28 July 2020 in Remote Sensing
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Journal Article
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MPMolly H. Polk
Molly H. Polk
NMNiti Mishra
Niti Mishra
KYKenneth Young
Kenneth Young
KMKumar P Mainali
Kumar P Mainali
If he were living today, Alexander von Humboldt would be using current technology to evaluate change in the Andes. Inspired by von Humboldt’s scientific legacy and the 2019 celebrations of his influence, we utilize a Moderate Resolution Imaging Spectroradiometer (MODIS)time-series vegetation index to ask questions of landscape change. Specifically, we use an 18-year record of Normalized Difference Vegetation Index (NDVI) data as a proxy to evaluate landscape change in Peru, which is well known for its high biological and ecological diversity. Continent-level evaluations of Latin America have shown sites with a positive trend in NDVI, or “greening” and “browning”, a negative trend in NDVI that suggests biophysical or human-caused reductions in vegetation. Our overall hypothesis was that the major biomes in Peru would show similar NDVI change patterns. To test our expectations, we analyzed the NDVI time-series with Thiel-Sen regression and evaluated Peru overall, by protected area status, by biome, and by biome and elevation. Across Peru overall, there was a general greening trend. By protected area status, surprisingly, the majority of greening occurred outside protected areas. The trends were different by biome, but there were hotspots of greening in the Amazon, Andean Highlands, and Drylands where greening dominated. In the Tropical Subtropical Dry Broadleaf Forest biome, greening and browning signals were mixed. Greening trends varied across the elevation gradient, switching from greening, to browning, and then back to greening as elevation increased. By biome and elevation, the results were variable. We further explored biome-specific drivers of greening and browning drawing on high-resolution imagery, the literature, and field expertise, much as we imagine von Humboldt might have approached similar questions of landscape dynamism.

11 November 2023 in Land
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Journal Article
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KYKenneth Young
Kenneth Young
EAEyner Alata
Eyner Alata
RCRodney A. Chimner
Rodney A. Chimner
RBRandall Boone
Randall Boone
GBGillian Bowser
Gillian Bowser
MZMelody Zarria-Samanamud
Melody Zarria-Samanamud
While the grazing of livestock has occurred for millennia in the Andes, current sustainability debates center on concerns with co-managing climate change and pastoralism. These discussions have special resonance in places protected by the state for biodiversity, scenery, and sustainable and traditional land uses, such as those found in protected areas and biosphere reserves. For this article, we integrate data from a social-ecological research project on the land use systems that affect high-elevation ecosystems in Peru’s Huascarán National Park, with special emphasis on the wetlands. We used land cover and land use data and insights from interactions with pastoralists to show that (1) wet meadows dominate the lower reaches of the park, while peatlands predominate above 4000 m elevation; (2) wet meadows are most useful for traditional grazing systems, while the peatlands are especially susceptible to trampling by livestock; and (3) there is limited ecological space at the highest elevations for the successful future upward relocation of either land use or potential habitats for species identified as of concern. We explore the implications of these findings for the adaptive strategies of biophysical and social processes in terms of livelihoods and biodiversity in and around a protected area. We conclude that there are many additional opportunities to be explored to inform the management of ecosystem services and provide improvements for the adaptive capacity of communities and park managers.