A combined grazing and fire management may reverse woody shrub encroachment in desert grasslands
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Fire and controlled grazing have been widely adopted as management interventions to counteract woody shrub proliferation in many arid and semiarid grassland systems. The actual intensity of grazing and fire, along with the timing of the interventions, however, are difficult to determine in practice.
This study aims to establish model simulations to access the long-term landscape changes under different land management scenarios.
We developed a cellular automata model to evaluate landscape dynamics in response to scenarios of grazing, fire, time of intervention, and initial coverage of grasses and shrubs.
With current grazing intensity and fire suppression, the landscape may shift to a shrub-dominated landscape in 100–150 years. An appropriate combination of grazing and fire management could help maintain over 50% of grass cover and reduce the shrub cover to less than 2%, keeping the landscape highly reversible. Even using 1% grazing intensity and periodic fire once a year, the management tools should be implemented in 60 years, otherwise, they may lose effectiveness and the vegetation transition to grasslands would become impossible.
This study highlighted that the reintroduction of fire not only directly removes shrubs but also reallocates soil water and resources among different microsites, which may accelerate grass recovery and suppress shrub regrowth, potentially reversing the shrub invasion process. The combined grazing and fire management plans should be carried out before a threshold time depending on the chosen management tools.
KeywordsShrub encroachment Cellular automata model Reversibility Arid and semiarid Landscape dynamics
This research was supported by the U.S. National Science Foundation Award EAR-1451489 for J. Li, EAR-1451518 for S. Ravi, and the Sevilleta LTER Summer Research Fellowship for G. Wang.
- Athanassopoulos S, Kaklamanis C, Kalfoutzos G, Papaioannou E (2012) Cellular automata: simulations using matlab. In: Proceedings of the sixth international conference on digital society (ICDS), pp 63–68Google Scholar
- Batty M (2007) Cities and complexity: understanding cities with cellular automata, agent-based models, and fractals. The MIT Press, CambridgeGoogle Scholar
- Brooks ML, Pyke DA (2002) Invasive plants and fire in the deserts of North America. In: Galley KEM, Wilson TP (eds) Proceedings of the Invasive Species Workshop: the role of fire in the control and spread of invasive species, Tall Timbers Research Station, Tallahassee, FL, pp 1–14Google Scholar
- Maestre FT, Bowker MA, Puche MD, Belén Hinojosa M, Martínez I, García-Palacios P, Castillo AP, Soliveres S, Luzuriaga AL, Sánchez AM, Carreira JA, Gallardo A, Escudero A (2009) Shrub encroachment can reverse desertification in semi-arid Mediterranean grasslands. Ecol Lett 12(9):930–941CrossRefPubMedGoogle Scholar
- Munson SM, Belnap J, Webb RH, Hubbdrd JA, Reiser MH, Gallo K (2014) Climate change and plant community composition in national parks of the Southwestern US: forecasting regional, long-term effects to meet management needs. George Wright Forum 31(2):137–148Google Scholar
- Puttock A, Macleod CJ, Bol R, Sessford P, Dungait J, Brazier RE (2013) Changes in ecosystem structure, function and hydrological connectivity control water, soil and carbon losses in semi-arid grass to woody vegetation transitions. Earth Surf Proc Land 38(13):1602–1611Google Scholar