
SAVANNA LAB
The whole world is a savanna; forests and grasslands are just special cases.
- Hanan, N.P., Limaye, A.S. & Irwin, D.E. (2020). Editorial: Use of earth observations for actionable decision making in the developing world. Frontiers in Environmental Science, 8, 601340. doi: 10.3389/fenvs.2020.601340.
- Hanan, N.P. & Anchang, J. (2020). Satellites could soon map every tree on Earth. Nature News & Views. doi: 10.1038/d41586-020-02830-3.
- Kumar, S.S., Prihodko, L., Lind, B.M., Anchang, J., Ji, W., Ross, C.W. et al. (2020). Remotely sensed thermal decay rate: an index for vegetation monitoring. Scientific Reports, 10, 9812. doi: 10.5061/dryad.v5s0j.
- Samasse, K., Hanan, N.P., Anchang, J. & Diallo, Y. (2020). A high-resolution cropland map for the West African Sahel based on high-density training data, Google Earth Engine & locally optimized machine learning. Remote Sensing, 12, 1436. doi: 10.3390/rs12091436.
- Anchang, J., Prihodko, L., Ji, W., Kumar, S.S., Ross, C.W., Yu, Q. et al. (2020). Towards operational mapping of woody canopy cover in tropical savannas using Google Earth Engine. Frontiers in Environmental Science, 8, 4. doi: 10.3389/fenvs.2020.00004.
- Brennan, J., Johnson, P. & Hanan, N.P. (2020). Comparing stability in random forest models to map northern Great Plains plant communities in pastures occupied by prairie dogs using Pleiades imagery. Biogeosciences, 17, 1281-1292. doi: 10.5194/bg-17-1281-2020.
- Kumar, S.S., Hanan, N.P., Prihodko, L., Anchang, J.Y., Ross, C.W., Ji, W. & Lind, B.M. (2019). Alternative vegetation states in tropical savannas: the search for consistent signals in diverse remote sensing data. Remote Sensing, 11, 815. doi: 10.3390/rs11070815.
- Anchang, J.Y., Prihodko, L., Kaptué, A.T., Ross, C.W., Ji, W., Kumar, S.S. et al. (2019). Trends in woody and herbaceous vegetation in the savannas of West Africa. Remote Sensing, 11, 576. doi: 10.3390/rs11050576.
- Ji, W., Hanan, N.P., Browning, D.M., Monger, H.C., Peters, D.P.C., Bestelmeyer, B.T. et al. (2019). Constraints on shrub cover and shrub-shrub competition in a U.S. southwestern desert. Ecosphere, 10, e02590. doi: 10.1002/ecs2.2590.
- Lind, B.M., Hanan, N.P., Gigliotti, L.C., Allen, R.L. McHenry, A. & Gardiner, A. (2019). Termite diversity along a catena in southern Kruger Park, South Africa. African Journal of Ecology, 57, 160-165. doi: 10.1111/aje.12569.
- Samasse, K., Hanan, N.P., Tappan, G. & Diallo, Y. (2018). Assessing cropland area in West Africa for agricultural yield analysis, Remote Sensing, 10, 1785. doi: 10.3390/rs10111785.
- Koerner, S.E., Smith, M.D., Burkepile, D.E., Hanan, N.P., Avolio, M. L., Collins, S.L. et al. (2018). Resolving variation in herbivore effects on plant biodiversity – change in dominance as a global mechanism. Nature Ecology and Evolution, 2, 1925-1932. doi: 10.1038/s41559-018-0696-y.
- Peters, D.P.C., Burruss, N., Rodriguez, L., McVey, D.S., Elias, E., Derner, J. et al. (2018). An integrated view of complex landscapes: a big data-model integration approach to trans-disciplinary research. Bio Science, 68, 653-669. doi: 10.1093/biosci/biy069.
- Hanan, N. P. (2018). Agroforestry in the Sahel. Nature Geoscience, 11, 296-297. doi: 10.1038/s41561-018-0112-x.
- Ross, C.W., Prihodko, L., Anchang, J., Kumar, S., Ji, W. & Hanan, N.P. (2018). HYSOGs250m, global gridded hydrologic soil groups for curve-number-based runoff modeling. Scientific Data, 5, 180091. doi: 10.1038/sdata.2018.91.
- Kahiu, M.N. & Hanan, N.P. (2018). Fire in sub-Saharan Africa: The fuel, cure and connectivity hypothesis. Global Ecology and Biogeography, 27, 946-957. doi: 10.1111/geb.12753.
- Axelsson, C.R. & Hanan, N.P. (2018). Rates of woody encroachment in African savannas reflect water constraints and fire disturbance. Journal of Biogeography, 45, 1209-1218. doi: 10.1111/jbi.13221.
- Kahiu, M.N. & Hanan, N.P. (2017). Estimation of woody and herbaceous leaf area index in Sub-Saharan Africa using MODIS data. J. Geophysical Research-Biogeosciences, 123, 3-17. doi: 10.1002/2017JG004105.
- Griffith, D.M., Lehmann, C.E.R., Strömberg, C.A.E., Parr, C.L., Pennington, R.T., Sankaran, M. et al. (2017). Comment on “The extent of forest in dryland biomes”. Science, 358, eaao1309. doi: 10.1126/science.aao1309.
- Gilmanov. T.G, Morgan, J.A., Hanan, N.P., Wylie, B.K., Rajan, N., Smith, D.P. et al. (2017). Productivity and CO2 exchange of Great Plains ecoregions. I. Shortgrass steppe: Flux-tower estimates. Rangeland Ecology & Management, 70, 700-717. doi: 10.1016/j.rama.2017.06.007.
- Axelsson, C.R. & Hanan, N.P. (2017). Patterns in woody vegetation structure across African savannas. Biogeosciences, 14, 3239-3252. doi: 10.5194/bg-14-3239-2017.
- Dohn, J., Augustine, D.J., Hanan, N.P., Ratnam, J. and Sankaran, M. (2017). Spatial vegetation patterns and neighborhood competition among woody plants in an East African savanna. Ecology, 98, 478-488. doi: 10.1002/ecy.1659.
- Yan, D., Zhang, X., Yu, Y., Guo, W. & Hanan, N.P. (2016). Characterizing land surface phenology and response to rainfall in the Sahara desert. J. Geophysical Research-Biogeosciences, 121, 2243-2260. doi: 10.1002/2016JG003441.
- Milne, E., Aynekulu, E., Bationo, A., Batjes, N.H., Boone, R., Conant, R. et al. (2016). Grazing lands in Sub-Saharan Africa and their potential role in climate change mitigation: What we do and don't know. Environmental Development, 19, 70-74. doi: 10.1016/j.envdev.2016.06.001.
- Petrie, M.D., Brunsell, N.A., Vargas, R., Collins, S.L., Flanagan, L.B., Hanan, N.P. et al. (2016). The sensitivity of carbon exchanges in Great Plains grasslands to precipitation variability. J. Geophysical Research-Biogeosciences, 121, 280-294. doi: 10.1002/2015JG003205.
- Kaptué, A.T., Prihodko, L. & Hanan, N.P. (2015). On re-greening and degradation in Sahelian watersheds. Proceedings of the National Academy of Science, 112, 12133-12138. doi: 10.1073/pnas.1509645112.
- Tredennick, A.T., Karembé, M., Dembélé, F. & Hanan, N.P. (2015). No effects of fire, large herbivores and their interaction on regrowth of harvested trees in two West African savannas. African Journal of Ecology, 53, 487-495. doi: 10.1111/aje.12238.
- Hanan, N.P., Tredennick, A.T., Prihodko, L., Bucini, G. & Dohn, J. (2015). Analysis of stable states in global savannas – a response to Staver and Hansen. Global Ecology and Biogeography, 24, 988-989. doi: 10.1111/geb.12321.
- Kaptué, A.T., Hanan, N.P., Prihodko, L. & Ramirez. J.A. (2015). Spatial and temporal characteristics of rainfall in Africa: summary statistics for temporal down-scaling. Water Resources Research, 51, 2668-2679. doi: 10.1002/2014WR015918.
- Tredennick, A.T. & Hanan, N.P. (2015). Effects of tree harvest on the stable-state dynamics of savanna and forest. American Naturalist, 185, E153-E165. doi: 10.1086/680475.
- Palmer, A.R., Weideman, C., Finca, A., Everson, C.S., Hanan, N.P. & Ellery, W. (2015). Modelling annual evapotranspiration in a semi-arid, African savanna: functional convergence theory, MODIS LAI and the Penman-Monteith equation. African Journal of Range and Forage Science, 32, 33-39. doi: 10.2989/10220119.2014.931305.
- Fan, Z., Neff, J.C. & Hanan, N.P. (2015). Modeling pulsed soil respiration in an African savanna ecosystem. Agricultural and Forest Meteorology, 200, 282-292. doi: 10.1016/j.agrformet.2014.10.009.
- Lehman, C.E.R., Anderson, T.M., Sankaran, M., Higgins, S.I., Archibald, S., Hoffmann, W.A. et al. (2014). Savanna vegetation-fire-climate relationships differ among continents. Science, 343, 548-552. doi: 10.1126/science.1247355.
- Hanan, N.P., Tredennick, A.T., Prihodko, L., Bucini, G. & Dohn, J. (2014). Analysis of stable states in global savannas: is the CART pulling the horse? Global Ecology and Biogeography, 23, 259-263. doi: 10.1111/geb.12122.
- Kaptue, A.T., Hanan, N.P. & Prihodko, L. (2013). Characterization of the spatial and temporal variability of surface water in the Soudan-Sahel region of Africa. Journal of Geophysical Research-Biogeosciences, 118, 1472-1483. doi: 10.1002/jgrg.20121.
- Tredennick, A.T., Bentley, L.P. & Hanan, N.P. (2013). Allometric convergence in savanna trees and implications for metabolic scaling theory in non-ideal systems. PLoS ONE, 8, e58241. doi: 10.1371/journal.pone.0058241.
- Sjöström, M., Zhao, M., Archibald, S., Arneth, A., Cappelaere, B., Falk, U. et al. (2013). Evaluation of MODIS gross primary productivity for Africa using eddy covariance data. Remote Sensing of Environment, 131, 275-286. doi: 10.1016/j.rse.2012.12.023.
- Gilmanov, T.G., Wylie, B.K., Tieszen, L.L., Meyers, T.P., Baron, V.S., Bernacchi, C.J. et al. (2013). CO2 uptake and ecophysiological parameters of the grain crops of midcontinent North America: Estimates from flux tower measurements. Agriculture, Ecosystems and Environment, 164, 162-175. doi: 10.1016/j.agee.2012.09.017.
- Dohn, J., Dembélé, F., Karembé, M., Moustakas, A., Amévor, K.A. & Hanan, N.P. (2013). Tree effects on grass growth in savannas: competition, facilitation and the stress-gradient hypothesis. Journal of Ecology, 101, 202-209. doi: 10.1111/1365-2745.12010.
- Anchang, Y., Kahiu, M.N., Ndungu, L.W., Ouko, E., Yu, Q., Ji, W., Prihodko, L. & Hanan, N.P. Year-round monitoring of vegetation conditions in an East African rangeland: Implications for livestock forage production in response to climate variability and local system shocks. American Geophysical Union Fall Meeting (virtual), Dec.1-17, 2020. Video link
- Yu, Q., Ji, W., Hanan, N.P., Prihodko, L. & Anchang, J. Framework for comparing plant height measurements from spaceborne LiDAR systems. American Geophysical Union Fall Meeting (virtual), Dec.1-17, 2020. Video link
- Ji, W. & Hanan, N.P. Shrub cover change in Southwest rangelands over the past decade. Jornada Symposium (virtual), Nov.12, 2020. Video link
- Ji, W., Hanan, N.P., Yu, Q., Fensham, R., Rohde, R., Anchang, J., Ross, C.W., Wojcikiewicz, R. & Prihodko, L. Rethinking global woody plant encroachment: Rates of change and the role of potential cover. Ecological Society of America Annual Meeting (virtual), Aug.3-6, 2020.
- Yu, Q., Ji, W., Hanan, N.P., Prihodko, L., Ross, C.W. & Anchang, J. Bifurcation and feedback mechanisms in tropical savannas. Ecological Society of America Annual Meeting (virtual), Aug.3-6, 2020.
- Hansen, T., Lind, B., Hanan, N.P. & Prihodko, L. Remote sensing of kangaroo rat mound demographics and mound impacts on landscape processes in the northern Chihuahuan desert. Ecological Society of America Annual Meeting (virtual), Aug.3-6, 2020.
- Hansen, T.M., Lind, B. & Hanan, N.P. Remote sensing of kangaroo rat mound demographics and mound impacts on landscape processes in the northern Chihuahuan Desert. American Geophysical Union Fall Meeting, San Francisco, CA, Dec.9-13, 2019.
- Ross, C.W., Hanan, N.P., Prihodko, L., Yu, Q., Ji, W. & Anchang, J. Satellite-derived estimates and 21st-century projections of biomass carbon in Sub-Saharan Africa. American Geophysical Union Fall Meeting, San Francisco, CA, Dec.9-13, 2019.
- Yu, Q., Hanan, N.P., Prihodko, L., Ji, W., Ross, C.W. & Anchang, J. Rage against the machine: ecological learning from machine learning. American Geophysical Union Fall Meeting, San Francisco, CA, Dec.9-13, 2019.
- Lind, B., Brandt, M., Kariryaa, A., Small, J.L., Melocik, K.A., Tucker, C.J. et al. Very high resolution satellite imagery reveals many millions of termite mounds across the West African Sahel. American Geophysical Union Fall Meeting, San Francisco, CA, Dec.9-13, 2019.
- Yu, Q., Hanan, N.P., Prihodko, L., Ji, W., Ross, C.W. & Anchang, J. Rage against the machine: ecological learning from machine learning. Workshop on Big Data Applications, Challenges & Techniques, Las Cruces, NM, Nov.22, 2019.
- Yu, Q., Ji, W., Hanan, N.P., Prihodko, L., Ross, C.W. & Anchang, J. Alternative states and feedback mechanisms in tropical savannas diagnosed via length-scales of canopy aggregation. New Mexico State University Research and Creativity Week, Las Cruces, NM, Nov.11-15, 2019.
- Ji, W., Hanan, N.P., Hansen, T.M. & Lind, B. The effects of topo-edaphic factors on 47 years of shrub encroachment in nortern Chihuahuan Desert. New Mexico State University Research and Creativity Week, Las Cruces, NM, Nov.11-15, 2019.
- Prihodko, L., Hanan, N.P., Ross, C.W., Yu, Q., Bucini, G. & Trdennick, A. Shrub and tree canopy cover and above-ground woody biomass patterns in Sub-Saharan Africa. New Mexico State University Research and Creativity Week, Las Cruces, NM, Nov.11-15, 2019.
- Anchang, J., Prihodko, L., Ji, W., Ross, C.W., Yu, Q., Lind, B. & Hanan, N.P. Supporting local livelihoods in West Africa through cloud-based geospatial analysis. New Mexico State University Research and Creativity Week, Las Cruces, NM, Nov.11-15, 2019.
- Ross, C.W., Hanan, N.P., Prihodko, L., Anchang, J., Ji, W. & Yu, Q. The distribution of woody biomass in the African Anthropocene. New Mexico State University Research and Creativity Week, Las Cruces, NM, Nov.11-15, 2019.
- Hanan, N.P. Perspectives on plant population dynamics in semi-arid ecosystems. Invited presentation, Arizona State University, Biology Department Seminar, Tempe, AZ, Nov.1, 2019.
- Hanan, N.P. Perspectives on plant population dynamics in semi-arid ecosystems. Invited presentation, University of New Mexico, Albuquerque, NM, Sep.26, 2019.
- Ross, C.W., Hanan, N.P., Prihodko, L., Yu, Q., Ji, W. & Anchang, J. The distribution of woody biomass in sub-Saharan Africa: An analysis of climate change and anthropogenic drivers. NASA Terrestrial Ecology Science Team Meeting, College Park, MD, Sep.23-25, 2019.
- Hanan, N.P., Prihodko, L., Ross, C.W., Yu, Q. & Kumar, S. Bistability and feedbacks in tropical woodlands and savannas: Carbon cycle implications of changing climate and management. Invited presentation, NASA Terrestrial Ecology Science Team Meeting, College Park, MD, Sep.23-25, 2019.
- Yu, Q., Ji, W., Hanan, N.P., Prihodko, L., Ross, C.W. & Anchang, J. Alternative states and feedback mechanisms in tropical savannas diagnosed via length-scales of canopy aggregation. NASA Terrestrial Ecology Science Team Meeting, College Park, MD, Sep.23-25, 2019.
- Hanan, N.P., Yu, Q., Ross, C.W. & Anchang, J. Machine learning: friend and foe of geospatial and ecological science. Invited Presentation, ARS SCINet Workshop, Las Cruces, NM, Sep.11, 2019.
- Prihodko, L., Hanan, N.P., Ross, C.W., Anchang, J. & Ji, W. A new approach to woody biomass assessments in tropical woodlands and savannas of Sub-Saharan Africa. International Savanna Science Network Meeting, Skukuza, South Africa, Mar.3-8, 2019.
- Ji, W., Prihodko, L., Hanan, N. P., Yu, Q., Ross, C. W., Anchang, J. Do we need to rethink how we think about woody plant encroachment? International Savanna Science Network Meeting, Skukuza, South Africa, Mar.3-8, 2019.
- Ross, C.W., Hanan, N.P., Prihodko, L., Anchang, J., Ji, W., Yu, Q. et al. Drivers of woody vegetation across sub-Saharan Africa. International Savanna Science Network Meeting, Skukuza, South Africa, Mar.3-8, 2019.
- Anchang, J., Prihodko, L., Ross, C.W., Ji, W., Lind, B. & Hanan, N.P. Trends in woody and herbaceous conditions in the savannas of West Africa. International Savanna Science Network Meeting, Skukuza, South Africa, Mar.3-8, 2019.
- Lind, B. & Hanan, N.P. Blast from the past: termite mound demographics and landscape change in the KNP 1966-2015. International Savanna Science Network Meeting, Skukuza, South Africa, Mar.3-8, 2019.
- Peters, D.P.C., Bestelmeyer B., Okin, G., Sala, O., Vivoni, E.R., Schooley, R.L. et al. Data-model integration to develop a knowledge landscape for improved prediction. American Geophysical Union Fall Meeting, Washington DC, Dec.10-14, 2018.
- Lind, B. & Hanan, N.P. Blast from the past: Using current and archival high resolution imagery to explore termite mound demographics and landscape change in Sahelian savannas. American Geophysical Union Fall Meeting, Washington DC, Dec.10-14, 2018.
- Ross, C.W., Hanan, N.P., Prihodko, L., Anchang, J., Ji, W., Kumar, S.S. et al. Development of predictive relationships for empirical projections of sub-Saharan woody cover in response to global change. American Geophysical Union Fall Meeting, Washington DC, Dec.10-14, 2018.
- Kumar, S.S., Prihodko, L., Hanan, N.P., Lind, B.M., Ross, C.W., Ji, W. et al. Remotely sensed thermal decay constant as a quantitative biophysical measure of vegetation status. American Geophysical Union Fall Meeting, Washington DC, Dec.10-14, 2018.
- Ji, W., Hanan, N.P., Browning, D.M., Monger, H.C., Peters, D.P.C., Bestelmeyer, B. et al. Relationship between shrub cover and plant available water in a U.S. Southwest desert. American Geophysical Union Fall Meeting, Washington DC, Dec.10-14, 2018.
- Hanan, N.P. & Prihodko, L. Energy-nutrition tradeoffs and mobility in subsistence pastoral systems of West Africa. Invited presentation, Ecological Society of America Annual Meeting, New Orleans, LA, Aug.5-10, 2018.
- Prihodko, L., Hanan, N.P., Bucini, G., Tredennick, A.T., Kumar, S.S. & Ross, C.W. Shrub and tree canopy cover and above-ground woody biomass patterns in Sub-Saharan Africa. Ecological Society of America Annual Meeting, New Orleans, LA, Aug.5-10, 2018.
- Petrie, M.D., Peters, D.P.C., Burruss, D., Ji, W., Hanan, N.P. & Savoy, H.M. Regional telecoupling and impacts of wet periods across the Chihuahuan Desert of the United States and northern Mexico. Ecological Society of America Annual Meeting, New Orleans, LA, Aug.5-10, 2018.
- Anchang, J. & Hanan, N.P.. Analysis of long-term degradation and drought recovery trends in the West African Sahel-Soudan. Invited presentation, UN Sustainable Development Goals (UNSDG) and GEO-GLAM Rangeland and Pasture Productivity (RAPP) Workshop, International Livestock Research Institute, Nairobi, Kenya, May.7, 2018.
- Ross, C.W., Prihodko, L., Anchang, J., Ji, W. & Hanan, N.P. HYSOGs250m: A globally consistent, gridded dataset for curve-number-based runoff modeling with hydrological soil groups. American Association of Geographers Annual Meeting, New Orleans, LA, Apr.10-14, 2018.
- Mason, W.S., Hanan, N.P., Ji, W. & Kumar, S.S. UAV pilot project at the Jornada LTER. American Association of Geographers Annual Meeting, New Orleans, LA, Apr.10-14, 2018.
- Kahiu, M.N. & Hanan, N.P. Forage estimates from partitioned woody and herbaceous leaf area index: An opportunity for improved index-based livestock insurance. International Livestock Research institute (ILRI), Nairobi, Kenya, Jan.12, 2018.
- Hanan, N.P., Anchang, J., Dieye, A.M., Yéro, K. & Tredennick, A.T. Satellite based analysis of wood biomass and fuelwood sustainability in Senegal. American Geophysical Union Fall Meeting, New Orleans, LA, Dec.11-15, 2017.
- Anchang, J., Hanan, N.P., Prihodko, L., Ji, W., Kumar, S.S. & Ross, C.W. Diagnosing long-term vegetation trends within woody and herbaceous sub-systems in the West African savanna-Sahel region. American Geophysical Union Fall Meeting, New Orleans, LA, Dec.11-15, 2017.
- Kumar, S.S., Hanan, N.P., Prihodko, L., Anchang, J., Ji, W. & Ross, C.W. Alternative vegetation states in tropical Africa: the search for consistent signals in diverse remote sensing datasets. American Geophysical Union Fall Meeting, New Orleans, LA, Dec.11-15, 2017.
- Herrick, J., Okin, G., Bestelmeyer, B., Hanan, N.P., Neff, J.C., Peters, D.P.C. et al. Dirt: integrating scientific and local knowledge to support global land management. American Geophysical Union Fall Meeting, New Orleans, LA, Dec.11-15, 2017.
- Hanan, N.P. Patterns and processes of vegetation change in semi-arid ecosystems. Invited presentation, 14th Annual Research in Semi-Arid Ecosystems (RISE) Symposium, University of Arizona, Tucson, AZ, Oct.21, 2017.