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Global rangelands and their role in food security Temuulen “Teki” Sankey Northern Arizona University Flagstaff, AZ.

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Presentation on theme: "Global rangelands and their role in food security Temuulen “Teki” Sankey Northern Arizona University Flagstaff, AZ."— Presentation transcript:

1 Global rangelands and their role in food security Temuulen “Teki” Sankey Northern Arizona University Flagstaff, AZ

2 Background I am a plant ecologist/dendrochronologist/RS I study rangeland use/land cover changes: – Intermountain USA: grassland-forest ecotones, aspen and pinyon-juniper woodlands – Great Basin: sagebrush shrublands – Sonoran Desert: desert invasive forbs – Central Asia: grassland steppe

3 Cropland Grassland Shrubland Woodland Rangeland dynamics Time YearsDecades

4 Western US Rangelands Climate change and land management-induced changes – Fire – Woody encroachment

5 Western US Rangelands Wildfires are increasing in frequency and extent

6 Idaho Rangelands Cheatgrass invasion – Fire cycle feedback – Sagebrush recovery

7 Post-fire recovery in sagebrush 16 fires since 1937 SPOT image Sankey et al Post-fire recovery of sagebrush communities: Assessment using SPOT5 and Very Large Scale Aerial Imagery. Rangeland Ecology and Management 61:

8 Post-fire recovery in sagebrush Mountain big sagebrush Mean cover = 38% Time = 27 years Sankey et al Post-fire recovery of sagebrush communities: Assessment using SPOT5 and Very Large Scale Aerial Imagery. Rangeland Ecology and Management 61:

9 Sagebrush characterization - Lidar Classify sagebrush communities Shrub height Sankey, T. and P. Bond Lidar-based classification of sagebrush community types. Rangeland Ecology and Management 64: 92-98

10 Sagebrush Height - Lidar Sankey, T. and P. Bond Lidar-based classification of sagebrush community types. Rangeland Ecology and Management 64: 92-98

11 Sagebrush Height - Lidar Sankey, T. and P. Bond Lidar-based classification of sagebrush community types. Rangeland Ecology and Management 64: 92-98

12 Sagebrush Height - Lidar

13 Western Rangelands: Juniper encroachment Juniper cover increase: % Encroachment leads to: – Understory vegetation loss – Soil erosion – Habitat loss – Fire hazard Control treatment – Prescribed fire – Cutting – Shredding

14 Juniper encroachment Quantify encroachment rates and patterns Identify priority areas for control treatment

15 Juniper encroachment Sankey et al Characterizing western juniper expansion via a fusion of Landsat 5 Thematic Mapper and lidar data. Rangeland Ecology and Management 63: Landsat Fusion Lidar

16 Sankey et al Characterizing western juniper expansion via a fusion of Landsat 5 Thematic Mapper and lidar data. Rangeland Ecology and Management 63: Juniper encroachment

17 Sankey, T. and M. Germino Assessment of juniper encroachment with the use of satellite imagery and geospatial data. Rangeland Ecology and Management 61:

18 Juniper encroachment Sankey et al Lidar-derived carbon estimates in woody encroachment. Journal of Geophysical Research (In Press)

19 Juniper encroachment Sankey et al Lidar-derived carbon estimates in woody encroachment. Journal of Geophysical Research (In Press)

20 Juniper encroachment

21 Sankey et al Lidar-derived carbon estimates in woody encroachment. Journal of Geophysical Research (In Press)

22 Juniper encroachment Sankey et al Lidar-derived carbon estimates in woody encroachment. Journal of Geophysical Research (In Press)

23 Juniper encroachment Sankey et al Lidar-derived carbon estimates in woody encroachment. Journal of Geophysical Research (In Press)

24 Central Asian Rangelands Mongolia’s political changes Changes in herding practices Livestock numbers tripled

25 Changes in herd distribution

26 Effects on rangelands Landsat 5 TM 6 years: 1986, 1989,1990,…...shift… 2001, 2002, 2007 Collective vs post- collective Significant decrease

27 Rangelands vs Croplands Many abandoned fields in former socialist countries Abandoned fields were used as rangelands New shift now

28 Grassland Shrubland Woodland Cropland Rangeland dynamics Time YearsDecades

29 Croplands vs Rangelands Time YearsDecades

30 Crop Demand vs Supply Time YearsDecades Space Demand Supply?


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