The USDA has noted that soil is eroding at a rate of approximately 5 tons per year, although in many cases, sites can be losing closer to 100 tons per acre! Surface erosion can occur on slopes as flat at two percent [1] and is most likely to occur on medium-textured soils [2]. Erosion is most likely to occur on soils that experience reduced ground cover from fire, overgrazing and other disturbances. Restoration projects are often implemented on disturbed sites that are prone to soil erosion due to a lack of plant cover and alteration of soil structure. In many instances, revegetation is undertaken specifically to prevent erosion control, such as following wildfires or mechanical disturbance of a site.

Although seeding after disturbance can be an effective approach for minimizing subsequent erosion, the success of this approach is strongly dependent on initial cover of seeded species [3]. In addition to revegetation, surface mulches, biodegradable matting (like coconut fiber) and other man-made structures (such as wattles) that modify runoff flows can be effective in protecting soil from erosion, however, the reestablishment of permanent plant cover is generally the most effective approach for maintaining erosion control [4]. Fast growing species that develop large root systems can be particularly useful for arresting soil loss. There are commercial seed mixes available specifically for erosion control in California which are designed to revegetate sites without the need for irrigation (though success will depend on rainfall). Using jute netting and hydroseeding can be effective strategies for erosion prone hillsides [5]. However, hydroseeding such fast-growing species (or introducing them through other means) could have unintended consequences for native plant reestablishment. For example, in post-fire chaparral stands, hydroseeding with native grasses reduced the risk of erosion, but this treatment also hampered the establishment and growth of native shrub species [6]. 

Resources

• UCANR Fire Network | Erosion control
• Caltrans | Erosion control design
• NRCS | Homeowner’s guide to erosion control
• CNPS | Fire recovery guide
• Erosion Control and Revegetation on Santa Barbara Island in Channel Islands National Park
• Effectiveness of seed sowing techniques for sloped restoration sites

Fire is an important ecological process in many of California’s ecosystems, but the frequency and severity of wildfires in the State is increasing due to climate change, nonnative plant invasion, and decades of fire suppression leading to high fuel loads [1]. Catastrophic wildfires can have devastating effects on native plants and animals and water resources, as well as human life and property. Many plant species in California possess unique adaptations for surviving wildfires, but they may not be able to persist when historic fire regimes are altered.

Several land management approaches can be used to reduce wildfire risk. Controlling nonnative plant species, especially invasive annual grasses which easily catch and spread fire, can minimize fire risk [2]. Unless these invasives are replaced by natives, treatment will need to occur regularly (at least annually) to prevent the buildup of “flashy fuels”. In some forested ecosystems, woody fuel loads may need to be reduced through thinning or prescribed fire in order to prevent more catastrophic fires from occurring when the site experiences wildfire [3].

For some restoration projects in fire-prone areas, it is desirable to establish fire-resistant vegetation. Choosing native plant species that contain low levels of volatile oils or resins, maintain high moisture content with limited watering, and produce little dead or fine material can provide increased fire resistance in vulnerable areas [4]. Low irrigation of native shrubs (e.g., near homes or structures) can reduce fire hazards while maintaining the other benefits of native vegetation [5].

Resources

• CNPS | Fire recovery guide
• Theodore Payne Foundation | Landscaping for Wildfire Resilience
• Fire-Resistant Landscaping: A General Approach and Central Coast Perspective
• Designing for Fire — Homeowner Guidelines and Considerations for Native Planting

Rangelands cover millions of acres in California, encompassing a significant portion of the state’s diverse landscapes, including grasslands, shrublands, and woodlands. These rangelands are crucial for supporting biodiversity, providing habitat for wildlife, and sustaining agricultural practices, particularly livestock grazing, which is a key component of California’s economy [1]. While overgrazing can disturb native ecosystems, proper livestock management is not incompatible with ecological restoration and in some cases can be an important tool for conserving biodiversity and ecosystem functioning [2].

Although introduced species are often favored by livestock, native species can provide high forage value for a variety of grazing animals [3]. In specific circumstances, grazing may accelerate the recovery of poor condition rangelands [4]. Grazing, prescribed fire, and target mowing have all been shown to promote the recovery of desirable native perennial grasses [5,6]. The timing and intensity of grazing is a key determinant of outcomes for native vegetation. For example, strategic rest-rotational grazing can be used to restore rangelands to native bunchgrasses, improve water and carbon storage in the soil, and increase biodiversity while simultaneously sustaining forage potential [7]. Seeding of native plant species has the potential to sustain or enhance forage production [8] as well as limit the invasion of undesirable (i.e., unpalatable) nonnative plant species [9]. While bunchgrasses are often the target of grassland restoration, not all sites may be able to support these species. In fact, the majority of rangelands in California are annual systems [10]. In some sites where native vegetation consists of predominantly annual forbs, certain grazing practices could favor invasive annual grasses over native forbs [11].

Resources

• UC Rangelands
• Field Guide to Common California Rangeland and Pasture Plants
• California Native Grasslands Association
• USDA | Restoring California’s Native Grasses
• NRCS | Native Grasses Enhance Conservation and Forage Production in the Southwest

Declines in pollinator populations are a global concern, and restoring native plant communities is a key strategy for reversing this trend [1]. Although revegetation efforts for pollinators can be one of the most expensive types of restoration goals [2], pollinator habitat enhancement can indirectly benefit lots of other ecosystem services [3]. For example, creating hedgerows of native vegetation along crop field edges can substantially enhance the number and biodiversity of pollinators in agricultural landscapes [4]. Using pollinator seed mixes for restoration can also boost pollination visits of rare plant species that are targets for conservation [5].

Generally, pollinators require plants that flower at different times during the growing season, which enhances resource availability [6]. Strategic placement of restoration throughout a landscape can also enhance pollinator habitat. For example, connectivity across the landscape is important for the movement of many pollinators, including Monarchs. Restoring forbs (where appropriate) to riparian corridors, urban greenspaces, or hedgerows can enhance connectivity and promote healthy pollinator communities [7]. Additionally, planting in clumps, rather than a regular, spaced pattern across a landscape can enhance pollinator services [8].

Resources

• A Tool for Selecting Plants When Restoring Habitat for Pollinators
• Xerces Society | Pollinator Conservation Resources California
• CARCD | Pollinator and Wildlife Habitats
• Calscape | Pollinator Friendly Plants
• CNPS | Bee-friendly Gardening
• Pollinator Partnership | Planting Guides
• UC Master Gardeners | Natives for a Hedge Row

Post-fire restoration is a critical priority in California, where increasingly frequent and severe wildfires can dramatically alter landscapes [1]. In some areas, natural regeneration and passive restoration may be sufficient, especially where native vegetation and seedbanks remain intact. However, in heavily burned or degraded areas, active restoration is often necessary to stabilize soils, reduce erosion, and prevent the spread of invasive species. Even in areas where native species remain above ground or in the soil seedbank, invasive species, drought, and nitrogen deposition may hinder post-fire recovery [2]. Without intervention, many of these landscapes are at risk of converting to non-native annual grasslands, which not only reduce biodiversity but also increase future fire risk due to their flammability. Active restoration efforts help support long-term ecosystem resilience, protect water quality, and preserve native plant and animal communities.

Restoration after fire is not only costly [3] and time-consuming, but also requires careful planning and sustained effort to be successful. When approaching post-fire restoration in California, it’s important to start with site assessment to determine whether passive or active restoration is needed [4]. In areas requiring intervention, reseeding or planting native species adapted to local conditions can help jumpstart recovery. Seeding native annuals along with perennials can improve restoration success, reduce erosion, and better exclude nonnative weeds [5]. Mulching and installing erosion control structures may also be necessary on steep or bare slopes. Restoration practitioners should aim to act quickly after fire events, before invasive species establish dominance, and continue monitoring, weed control, and adaptive management for several years. Collaborating with local resource agencies and utilizing native seed and plant materials from regional sources will help ensure restoration efforts are ecologically appropriate and effective.

Resources

• Theodore Payne Foundation | Post-Fire Regeneration
• US Forest Service | Post-fire Restoration Framework for National Forests in California
• CNPS | Fire Recovery Guide
• California Fire Science Consortium | Fire Research
• Sonoma RCD | Fire Mitigation and Post-fire Recovery
• National Forest Foundation | Important Facts You Should Know About Post-Fire Restoration
• Identifying Priorities for Post-fire Restoration in California Chaparral 

When working with severely degraded soil (e.g. mine tailings, contaminated sites, or oil and gas pads), plants can be used for phytoremediation where seeded or planted species can stabilize or uptake soil contaminants. Establishing vegetation on severely degraded sites will also result in increased soil organic matter and nutrient content, however, stress tolerant plants must be selected to survive such harsh conditions as saline or acidic soils. Managers should be strategic in their restoration approach and use a variety of techniques when possible. For example, liquid gypsum can be used to remove salts and soften hard, compacted soils [1], while compost [2] and biochar [3] application may reduce toxicity of contaminated soils. Outcomes are likely to be context dependent. For example, at an abandoned golf course in California, the addition of gypsum was shown to reduce soil salinity, while biochar and fertilization increased native plant growth, but fertilization alone increased weed growth [4]. Soil biota play an important role in plant stress tolerance, and soil inoculations may be an important tool for rehabilitating and restoring degraded soils [5]. The addition or cultivation of native biological soil crusts (thin layer of cyanobacteria-lichen-bryophyte microbial communities on the soil surface) can also enhance plant community establishment as these crusts are critically important to soil structure and function in drylands [6]. Finally, planting plugs, rather than seeding, can be an effective way to inoculate soil with beneficial organisms that are living in the container soil [7]. Native soil biota are likely to be more effective in this regard than commercially available products [8].

Resources

• USGS | Field Guide to Biological Soil Crusts of the Western US
• EPA | The Use of Soil Amendments for Remediation, Revitalization, and Reuse
• EPA | Phytoremediation Resource Guide
• NRCS California Soils Program
• Rehabilitation of Disturbed Lands in California
• Phytoremediation Database
• National Association of Abandoned Mine Land Programs

Weed control is a crucial aspect of ecological restoration, but restoring native plant communities can also serve as a proactive measure to prevent weed establishment, a strategy sometimes called "competitive planting." Restoration practitioners can choose native species that are strong competitors against invasive weeds, enhancing the ecosystem’s resistance to invasion [1].  Mature plants are more likely to resist invasion than seedlings [2]. Incorporating a diverse mix of functional groups and lifeforms, such as annual forbs and perennial species, can further strengthen invasion resistance [3]. Additionally, selecting native species with phenologies similar to invasive weeds can be particularly effective. For instance, planting native summer annuals [4] or bunchgrasses [5] that are active later in the growing season can reduce the risk of invasion by yellow starthistle, which also grows and flowers later in summer. If there are known invasive species in adjacent sites, early detection and removal of weedy species may be necessary to keep the restoration site free from invasive species. Care should always be taken to keep construction/restoration equipment and any other sources of weed seed clean of soil and plant material when moving between sites so that the weeds are not spread from one disturbed site to another.

There are many reasons to restore wildlife habitat. For example, game species may be of interest, or landowners may be avid birders. Landowners might also need to adhere to requirements made by an agency such as the US Fish and Wildlife to include vegetation at a restoration site that supports existing wildlife in general, or to provide specific habitat structure or food sources for a threatened or endangered animal whose habitat may have been harmed. General wildlife habitat generally requires high heterogeneity in plant type and structure [1] while particular species of interest can be targeted with a strategic seed mix or plant palette. For example, seed eating desert rodents tend to prefer large-seeded winter annuals for food [2] while ants tend to specialize on smaller seeded species [3].

Resources

• Audubon | Plants for Birds
• Basic Steps for Habitat Gardening with California Native Plants
• CARCD | Pollinator and Wildlife Habitat
• CalFish | Restoration Projects
• Calscape | Support Wildlife
• CNPS | Habitat Gardening
• Coastal Restoration Toolkit for Wildlife & Fish Habitat
• NPS | Gardening for Wildlife with Native Plants
• WCB | Habitat Enhancement and Restoration Program

Case studies

• California gnatcatcher
• California tiger salamander
• Mojave desert tortoise
• San Joaquin kit fox
• Stephens’ kangaroo rat
• Western snowy plover
• Western spadefoot toad