A review of Holl’s, K.. 2020. Primer of Ecological Restoration. Island Press, Washington, DC, USA. For being a relatively new field in ecology, books and journal articles on Restoration Ecology abound. For students, academics, and practitioners in the field of ecology, the fate of our world and the constant drumbeat of habitat loss, climate change, extinction debts, and social inequity create a sense of profound sorrow. In the face of this, the field of restoration ecology really is the science of applied optimism (Palmer 2019). For any story we hear about water pollution, habitat degradation, or climate change, we can also find examples of restored forests, wetlands, prairies, and rivers (and many more ecosystems around the world!). While degradation and climate change certainly outpace restoration, the impediment to successful restoration is often social, political, and financial, more than due to a lack of scientific understanding. Although there is still much to learn about how ecosystems function, and how to put them back together following degradation, there is a lot that we do know. Often attributed to Einstein, a well-known quote states “If you can’t explain it simply, you don’t know it well enough.” Whether the attribution is correct or not, the maxim tells us that things do not need to be overly complicated, even when they are highly complex! In the “Primer of Ecological Restoration,” Dr. Holl shines as someone who clearly understands the field of ecological restoration well. Covering a range of topics related to the process of ecological restoration, Dr. Holl takes the reader through the various stages of ecological restoration and provides just enough information to appreciate why each step is meaningful and why it deserves attention. The reader will not come away ready to take the lead on an ecological restoration project, but that is not the stated goal of the book anyway. Primer of Ecological Restoration takes us through the project planning and monitoring steps, and provides a nice overview of a few important ecological theories underpinning restoration, while also going into some depth on restoring landforms, hydrology, and soils, before then thinking about revegetation. My personal favorite within this text is the focus on disturbance regimes as a fundamental organizing principle of ecosystems, and the need therefor to restore ecological processes (including physical, population, and community processes), rather than only focusing on revegetation. Of course, what we plant matters in the restoration process and can greatly influence the long-term trajectory of the developing community, but without addressing the processes that give rise to that particular ecosystem, we may be doing nothing more than gardening. I personally plan on using Chapter 6 (Landforms and Hydrology) in a graduate-level course on wetland ecology and restoration, and appreciate the incorporation of restoring hydrologic regimes rather than static water level depths or indicators. Dr. Holl’s focus on restoring processes as a fundamental goal of restoration is not new, but is a welcome shift from focusing on historic conditions or indicators. Good writing is an act of empathy with the reader. There are many books written on ecological restoration. Some broad and general, others specific to an ecosystem or an aspect of restoration; some of them are good, some of them are useful. Dr. Holl’s book happens to be both. It is clear serious thought has been given to who the possible reader to this would be and who might benefit from these general descriptions of the restoration process. At first blush, I can easily envision an undergraduate course in ecological restoration reading through these chapters, and using each to ensure their own hypothetical restoration design incorporates all the necessary detail. After further consideration, I can also quite easily picture colleagues who have led ecological restoration projects across many scales reading through this and reflecting on their own choices. Have they followed these steps? What might they include next time that they had not thought about? Were they actually able to successfully incorporate ecological theory into their practice? Are there collaborations they could seek out to increase their own learning with each restoration opportunity? This book does not provide much information for those interested in project management, stakeholder engagement, budgeting, or the oversight of construction activities during the restoration process, but that information is readily available in other texts. Instead, the reader gets to focus on ecological restoration from a high conceptual level, which then allows them to pursue other texts specific to details they are interested in. There is often a disconnect between the writers of articles and books and the practitioners doing the work. Sometimes the writers write without the context of reality, sometimes the practitioners carry on with little thought to ecological theory. This can too easily dissolve into a discussion about paywalls and the peer-reviewed process, but to pull us back from that brink we can also simply acknowledge the need to simplify. To tell the critical details, but no more. This book provides no danger of speaking over anyone or of speaking about ecological restoration without being grounded in reality, but neither does it trivialize anything along the way. I would highly recommend this text for students interested in ecological restoration and restoration ecology, for academics interested in the practical side of restoration, and for practitioners interested in reflecting on their own experiences. I am heartened by Dr. Holl’s call for increased collaboration between scientists and practitioners, and look forward to seeing more collaboration come to fruition after this solitary year we have all experienced!

Wet meadows are a common focus of wetland restoration efforts, and the species within them often exist within a restricted range of water levels. Unfortunately, many restored wetlands have higher water levels and more open water than naturally occurring reference wetlands, and many are invaded and dominated by species of Typha. Most studies evaluating the optimal water level for plant species use observational methods, yet experimental methods are required to understand the breadth of a species' niche. We used experimental transplants of Carex pellita, a common wet meadow sedge used in restoration in the interior of the USA, and Typha latifolia, a species of cattail which invades many restored wetlands, to test whether higher water levels in a restored wetland were prohibitive to the target sedge species. Physiological and growth measurements were collected on both species. We found that C. pellita grew as well or better when transplanted into the ponded water levels, while T. latifolia had reduced growth when transplanted into the relatively drier meadow conditions. Interestingly, C. pellita was able to adjust its Turgor Loss Point in response to changing water levels. Only recently the assumption of a constant Turgor Loss Point for each species has been questioned. Our results provide evidence that wet meadow species have a broader hydrologic niche than previously thought, and their ability to make physiological adjustments in response to changing water levels may allow them to thrive in areas with widely varying water levels.

Few wetland restoration projects include long‐term hydrologic and floristic data collection, limiting our understanding of community assembly over restored hydrologic gradients. Although reference sites are commonly used to evaluate outcomes, it remains unclear whether restoring similar water levels to reference sites also leads to similar plant communities. We evaluated long‐term datasets from reference and restored wetlands 15 years after restoration to test whether similar water levels in reference and restored sites led to vegetation similarity. We compared the hydrologic regimes for three different wetland types, tested whether restored wetland water levels were different from reference water levels, and whether hydrologic similarity between reference and restored wetlands led to similarity in plant species composition. We found restored wetlands had similar water levels to references 15 years after restoration, and that species richness was higher in reference than restored wetlands. Vegetation composition was similar across all wetland types and was weakly correlated to wetland water levels overall. Contrary to our hypothesis, water table depth similarity between restored and reference wetlands did not lead to similar plant species composition. Our results highlight the importance of the initial planting following restoration and the importance of hydrologic monitoring. When the restoration goal is to create a specific wetland type, plant community composition may not be a suitable indicator of restoration progress in all wetland types.

Cushion plant dominated peatlands are key ecosystems in tropical alpine regions of the Andes in South America. The cushion plants have formed peat bodies over thousands of years that fill many valley bottoms, and the forage produced by the plants is critical for native and nonnative domesticated mammals. The sources and flow paths of water supporting these peatlands remain largely unknown. Some studies have suggested that glacier meltwater streams support some peatlands, and that the ongoing loss of glaciers and their meltwaters could lead to the loss or diminishment of peatlands. We analysed the hydrologic regime of 10 peatlands in four mountain regions of Bolivia and Peru using groundwater monitoring. Groundwater levels in peatlands were relatively stable and within 20 cm of the ground surface during the rainy season, and many sites had water tables 40–90 cm below the ground surface in the dry season. Topographic and groundwater elevations in the peatlands demonstrated that the water source of all 10 peatlands was hillslope groundwater flowing from lateral moraines, talus, colluvium, or bedrock aquifers into the peatlands. There was little to no input from streams, whether derived from glacier melt or other sources, and glacier melt could not have recharged the hillslope aquifers supporting peatlands. We measured the stable water isotopes in water samples taken during different seasons, distributed throughout the catchments, and the values are consistent with this interpretation. Our findings indicate that peatlands in the study region are recharged by hillslope groundwater discharge rather than stream water and may not be as vulnerable to glacial decline as other studies have indicated. However, both glaciers and peatlands are susceptible to changing thermal and precipitation regimes that could affect the persistence of peatlands.

The wetland resources of Colorado have been severely impacted by development activities over the past few centuries. Wetland restoration, enhancement, creation, and preservation are necessary steps in the conservation of wetland resources across the landscape, yet are often limited by a lack of landscape-level information. The Landscape, Landform, Water Flow Path, and Water Body (LLWW) classification developed for the Southern Rockies of Colorado by the Colorado Natural Heritage Program is designed to provide management-relevant information on Colorado's wetland resources to decision-makers. From impact avoidance and mitigation opportunities for development projects to the identification of preservation opportunities and strategic investments for land trusts, the Southern Rockies LLWW is meant to serve as a tool to protect, enhance, and restore Colorado's wetlands. The Southern Rockies LLWW is based on the original LLWW classification that has been used throughout the country, and updated for the Southern Rockies landscape to account for prominent differences in wetland hydrology, ecology, and geography in western landscapes. The Southern Rockies LLWW has been used to characterize wetlands in two prominent mountain watersheds in Colorado and will be provided as an online watershed toolbox to project partners and the general public.

Wetland restoration performed as a requirement of compensatory mitigation does not always replace lost acreage or functions. Most new projects are required to identify performance standards to evaluate restoration outcomes. Current performance standards are primarily related to vegetation with little to no evaluation of wetland hydrologic regimes. Because of the agreement in the scientific literature about the role of hydrology in creating and maintaining wetland structure and function, hydrologic performance standards may be an ecologically meaningful way to evaluate restoration outcomes. This research tests the use of water level data from project specific reference sites to evaluate restored water levels for three distinct wetland types across the United States. We analyzed existing datasets from past and ongoing wetland mitigation projects to identify the number of years it took water levels in restored wetlands to match reference sites, and to test whether similar water levels between restored and reference sites leads to increased vegetation success. Wetland types differed in the number of years it took for water levels to match reference sites. Vernal pools in California took nine years to match reference sites, fens and wet meadows in Colorado took four years, and forested wetlands in the southeastern US were hydrologically similar to reference sites the first year following restoration. Plant species cover in all three restored wetland types was related to the water level similarity to reference sites. Native cover was higher when water levels were more similar to reference sites, and was lower in areas where water levels were different. Exotic species cover showed the opposite relationship in fens and wet meadows, where hydrologic similarity led to low cover of exotic species. Along with the general agreement of the importance of hydrology for wetland form and function, this research shows that hydrologic performance standards may also lead to increased vegetation success in some wetland types.

Twelve wetland complexes were buried and/or drained by golf course and ski area development in the Colorado Rocky Mountains in the 1980s and early 1990s. We restored all or portions of each wetland, including fens, wet meadows and riparian areas, during 1997-2002. Intensive pre- and post-construction monitoring was used to develop restoration plans and evaluate their success. We revisited the sites to analyze long-term restoration processes in 2013-2016. Prior to construction the depth to the water table was measured weekly in monitoring wells installed through the fill, and into the wetland surfaces during and following restoration. Reference sites for each wetland type were used to characterize water tabledepth and vegetation for each wetland type. Restoration included removal of fill material and drains to create land surfaces with water table depth and dynamics similar to the reference areas for each wetland type. We planted each site with nursery grown sedges, willows and herbaceous dicots. Post restoration monitoring of water table depth, vegetation composition, sedge shoot density and willow growth was analyzed.The water table depth and dynamics of each restored wetland was similar to suitable reference sites on short and long time scales, indicating a stable hydrologic regime. Carex utriculata reached its maximum shoot density 4-5 years after planting indicating rapid growth and high production. Willow stems were still increasing in height 15 years after planting and basal stem density was also increasing. Most planted herbaceous dicots disappeared, indicating the difficulty of establishing them from plantings. Exotic (nonnative) plants have invaded all three wetland types, with their highest cover in riparian areas. Critical factors that led to success were careful hydrological analysis of reference and restoration sites prior to earthwork, creating appropriate land/ground water interactions, and establishing clonal rhizomatoussedges and native willows. (C) 2017 Elsevier B.V. All rights reserved.

(1) The high-altitude (4,500+ m) Andean mountain range of north-western Bolivia contains many peatlands. Despite heavy grazing pressure and potential damage from climate change, little is known about these peatlands. Our objective was to quantify carbon pools, basal ages and long-term peat accumulation rates in peatlands in two areas of the arid puna ecoregion of Bolivia: near the village of Manasaya in the Sajama National Park (Cordillera Occidentale), and in the Tuni Condoriri National Park (Cordillera Real). (2) We cored to 5 m depth in the Manasaya peatland, whose age at 5 m was ca. 3,675 yr. BP with a LARCA of 47 g m^-2^ yr^-1^. However, probing indicated that the maximum depth was 7–10 m with a total estimated (by extrapolation) carbon stock of 1,040 Mg ha^-1^. The Tuni peat body was 5.5 m thick and initiated ca. 2,560 cal. yr. BP. The peatland carbon stock was 572 Mg ha^-1^ with a long-term rate of carbon accumulation (LARCA) of 37 g m^-2^ yr^-1^. (3) Despite the dry environment of the Bolivian puna, the region contains numerous peatlands with high carbon stocks and rapid carbon accumulation rates. These peatlands are heavily used for llama and alpaca grazing.

Irrigation has increased agricultural productivity in the arid American West, and has greatly altered the natural landscape. This study sought to identify the hydrologic processes linking irrigation canals and reservoirs to wetlands. We mapped wetlands within an irrigation company service area in northern Colorado, measured groundwater levels, and used stable oxygen isotopes to identify groundwater sources. We related vegetation composition in study wetlands to environmental variables to identify the types of wetlands supported by leakage from irrigation conveyance and storage structures. Ninety-two percent of wetlands were visually connected to the irrigation infrastructure. Wetland water tables varied with adjacent canal flow, and isotopic data indicated that wetlands within the study area were recharged solely by canal leakage. Wetland vegetation composition was related to both soil salinity and groundwater depth. Salt flats formed in areas with high salinity, marsh communities in areas with low salinity and higher standing water, and meadow communities in areas with low salinity and water tables near the ground surface. Though land conversion and water diversions have led to dramatic reductions in historic wetland area in some places, it is clear from our study that current agricultural landscapes create wetlands that rely on irrigation water.