Approach
EASTERN:
Competition for resources between plants is established as one of the main mechanisms in plant succession and evolution (Weiner 1990). Competition occurs aboveground as plants compete for light, and belowground as they compete for water and mineral nutrients (Casper and Jackson 1997). Climate change is expected to affect many of the competitive relationships in forest ecosystems. Productivity may increase because of the positive effects of carbon dioxide (CO2) fertilization and longer growing seasons. But not all species will be able to take equal advantage of these positive effects (Evans and Perschel 2009). Reducing competition for resources can enhance the persistence of desired species and increase the ability of ecosystems to cope with the direct effects (drought stress, temperature increases) and indirect effects (increased damage from pests and disease) of climate change (Dwyer et al.2010, Evans and Perschel 2009). (1)
WESTERN:
Competition for resources between plants is established as one of the main mechanisms in plant succession and evolution (Weiner 1990). Competition occurs aboveground as plants compete for light, and belowground as they compete for water and mineral nutrients (Casper and Jackson 1997). Climate change is expected to affect many of the competitive relationships in California’s forest and shrubland ecosystems, Adaptation Strategies and Approaches for California Forest Ecosystems 14 suggesting that management and reforestation practices may need adjustment (Hessburg et al. 2016, Hagerman and Pelai 2018, North et al. 2019). Productivity may increase in some species because of the positive effects of carbon dioxide (CO2) fertilization and longer growing seasons, but other species will not be able to take equal advantage of these positive effects (Evans and Perschel 2009). On the other hand, increased temperatures, a contracted wet season, lower rates of precipitation, or reduced snowpack will increase competition for water, and increase the susceptibility of trees to many pests and pathogens. Reducing competition for resources can enhance the persistence of remaining individuals of desired species and increase the ability of ecosystems to cope with the direct effects (drought stress, temperature increases) and indirect effects (increased damage from pests and disease) of climate change (Evans and Perschel 2009, Dwyer et al. 2010, Hessburg et al. 2016, Wang et al. 2019, North et al. 2019). The effectiveness of reducing competition in terms of improving forest condition will vary based on many factors, such as species sensitivities, site condition, and degree of climate exposure; moreover, even if competition is reduced, there may not be a change in factors like vegetation or soil moisture (e.g., Stevens et al. 2020), and despite management actions, climate change may still push species past critical ecological thresholds (Crausbay et al. 2017). (2)
Competition for resources between plants is established as one of the main mechanisms in plant succession and evolution (Weiner 1990). Competition occurs aboveground as plants compete for light, and belowground as they compete for water and mineral nutrients (Casper and Jackson 1997). Climate change is expected to affect many of the competitive relationships in forest ecosystems. Productivity may increase because of the positive effects of carbon dioxide (CO2) fertilization and longer growing seasons. But not all species will be able to take equal advantage of these positive effects (Evans and Perschel 2009). Reducing competition for resources can enhance the persistence of desired species and increase the ability of ecosystems to cope with the direct effects (drought stress, temperature increases) and indirect effects (increased damage from pests and disease) of climate change (Dwyer et al.2010, Evans and Perschel 2009). (1)
WESTERN:
Competition for resources between plants is established as one of the main mechanisms in plant succession and evolution (Weiner 1990). Competition occurs aboveground as plants compete for light, and belowground as they compete for water and mineral nutrients (Casper and Jackson 1997). Climate change is expected to affect many of the competitive relationships in California’s forest and shrubland ecosystems, Adaptation Strategies and Approaches for California Forest Ecosystems 14 suggesting that management and reforestation practices may need adjustment (Hessburg et al. 2016, Hagerman and Pelai 2018, North et al. 2019). Productivity may increase in some species because of the positive effects of carbon dioxide (CO2) fertilization and longer growing seasons, but other species will not be able to take equal advantage of these positive effects (Evans and Perschel 2009). On the other hand, increased temperatures, a contracted wet season, lower rates of precipitation, or reduced snowpack will increase competition for water, and increase the susceptibility of trees to many pests and pathogens. Reducing competition for resources can enhance the persistence of remaining individuals of desired species and increase the ability of ecosystems to cope with the direct effects (drought stress, temperature increases) and indirect effects (increased damage from pests and disease) of climate change (Evans and Perschel 2009, Dwyer et al. 2010, Hessburg et al. 2016, Wang et al. 2019, North et al. 2019). The effectiveness of reducing competition in terms of improving forest condition will vary based on many factors, such as species sensitivities, site condition, and degree of climate exposure; moreover, even if competition is reduced, there may not be a change in factors like vegetation or soil moisture (e.g., Stevens et al. 2020), and despite management actions, climate change may still push species past critical ecological thresholds (Crausbay et al. 2017). (2)
Tactics
- Using herbicide or mechanical thinning to prevent the encroachment of woody competitors and invasive species, especially after disturbance (1).
- Using prescribed fire to maintain growing space for fire-tolerant species or to increase nutrient turnover (1).
- Thinning forest stands to remove crowded, damaged, or stressed trees in order to reduce competition for light, nutrients, and water (1).
- Fertilizing or amending soil to address nutrient deficiencies (1).
- Controlling beech suckers, sprouts, and brush with herbicides or mechanical treatment in areas affected by beech bark disease in order to reduce competition with the regeneration of other species (1).
- Using prescribed fire, managed wildfire, pyrosilviculture, or mechanical thinning to increase light and moisture availability and stimulate growth, recruitment, and regeneration in aspen and other broadleaved or coniferous shade-intolerant trees (2).
- Mechanical or herbicidal removal of encroaching woody competitors and invasive species in post-disturbance environments to enhance the survivorship and growth of natural or planted regeneration of desired species (2).
- Mechanical thinning of forest stands (i.e., reduce tree density) in order to decrease competition for light, nutrients, and water and increase the survivorship and health of larger and older trees (2).
- Using prescribed fire in forests to maintain or increase growing space for fire-tolerant species, promote regeneration of shade-intolerant species, enhance soil moisture availability, or increase nutrient turnover (2).
- Applying variable density thinning treatments to enhance structural heterogeneity and reduce inter-tree competition while balancing other management objectives (e.g., maintaining wildlife habitat, fuel reduction) (2).
Strategy Text
Climate change will have substantial effects on a suite of ecosystem functions, such as carbon storage, nutrient cycling, wildlife habitat, hydroelectric generation and water provisioning. As a result, many management actions will need to work both directly and indirectly to maintain the integrity of ecosystems in the face of climate change. This strategy seeks to sustain fundamental ecological functions, especially
those related to soil and hydrologic conditions (2).
those related to soil and hydrologic conditions (2).
Citation
1. Swanston, C.W.; Janowiak, M.K.; Brandt, L.A.; Butler, P.R.; Handler, S.D.; Shannon, P.D.; Derby Lewis, A.; Hall, K.; Fahey, R.T.; Scott, L.; Kerber, A.; Miesbauer, J.W.; Darling, L.; 2016. Forest Adaptation Resources: climate change tools and approaches for land managers, 2nd ed. US Department of Agriculture, Forest Service, Northern Research Station. 161 p. http://dx.doi.org/10.2737/NRS-GTR-87-2,
2. Swanston, C.W.; Brandt, L.A.; Butler-Leopold, P.R.; Hall, K.R.; Handler, S.D.; Janowiak, M.K.; Merriam, K.; Meyer,
M.; Molinari, N.; Schmitt, K.M.; Shannon, P.D.; Smith, J.B.; Wuenschel, A.; Ostoja, S.M 2020. Adaptation Strategies
and Approaches for California Forest Ecosystems. USDA California Climate Hub Technical Report CACH-2020-1.
Davis, CA: U.S. Department of Agriculture, Climate Hubs. 65 p.
M.; Molinari, N.; Schmitt, K.M.; Shannon, P.D.; Smith, J.B.; Wuenschel, A.; Ostoja, S.M 2020. Adaptation Strategies
and Approaches for California Forest Ecosystems. USDA California Climate Hub Technical Report CACH-2020-1.
Davis, CA: U.S. Department of Agriculture, Climate Hubs. 65 p.