Biomass harvest of invasive Typha promotes plant diversity in a Great Lakes coastal wetland

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111287/1/rec12167.pd

Typha (Cattail) Invasion in North American Wetlands: Biology, Regional Problems, Impacts, Ecosystem Services, and Management

Typha is an iconic wetland plant found worldwide. Hybridization and anthropogenic disturbances have resulted in large increases in Typha abundance in wetland ecosystems throughout North America at a cost to native floral and faunal biodiversity. As demonstrated by three regional case studies, Typha is capable of rapidly colonizing habitats and forming monodominant vegetation stands due to traits such as robust size, rapid growth rate, and rhizomatic expansion. Increased nutrient inputs into wetlands and altered hydrologic regimes are among the principal anthropogenic drivers of Typha invasion. Typha is associated with a wide range of negative ecological impacts to wetland and agricultural systems, but also is linked with a variety of ecosystem services such as bioremediation and provisioning of biomass, as well as an assortment of traditional cultural uses. Numerous physical, chemical, and hydrologic control methods are used to manage invasive Typha, but results are inconsistent and multiple methods and repeated treatments often are required. While this review focuses on invasive Typha in North America, the literature cited comes from research on Typha and other invasive species from around the world. As such, many of the underlying concepts in this review are relevant to invasive species in other wetland ecosystems worldwide

Harvesting Invasive Plants to Reduce Nutrient Loads and Produce Bioenergy: An Assessment of Great Lakes Coastal Wetlands

In Laurentian Great Lakes coastal wetlands (GLCWs), dominant emergent invasive plants are expanding their ranges and compromising the unique habitat and ecosystem service values that these ecosystems provide. Herbiciding and burning to control invasive plants have not been effective in part because neither strategy addresses the most common root cause of invasion, nutrient enrichment. Mechanical harvesting is an alternative approach that removes tissue‐bound phosphorus and nitrogen and can increase wetland plant diversity and aquatic connectivity between wetland and lacustrine systems. In this study, we used data from three years of Great Lakes‐wide wetland plant surveys, published literature, and bioenergy analyses to quantify the overall areal extent of GLCWs, the extent and biomass of the three most dominant invasive plants, the pools of nitrogen and phosphorus contained within their biomass, and the potential for harvesting this biomass to remediate nutrient runoff and produce renewable energy. Of the approximately 212,000 ha of GLCWs, three invasive plants (invasive cattail, common reed, and reed canary grass) dominated 76,825 ha (36%). The coastal wetlands of Lake Ontario exhibited the highest proportion of invasive dominance (57%) of any of the Great Lakes, primarily from cattail. A single growing season\u27s biomass of these invasive plants across all GLCWs was estimated at 659,545 metric tons: 163,228 metric tons of reed canary grass, 270,474 metric tons of common reed, and 225,843 metric tons of invasive cattail, and estimated to contain 10,805 and 1144 metric tons of nitrogen and phosphorus, respectively. A one‐time harvest and utilization for energy of this biomass would provide the gross equivalent of 1.8 million barrels of oil if combusted, or 0.9 million barrels of oil if converted to biogas in an anaerobic digester. We discuss the potential for mitigating non‐point source nutrient pollution with invasive wetland plant removal, and other potential uses for the harvested biomass, including compost and direct application to agricultural soils. Finally, we describe the research and adaptive management program we have built around this concept, and point to current limitations to the implementation of large‐scale invasive plant harvesting

Biomass harvest of invasive Typha promotes plant diversity in a Great Lakes coastal wetland

Ecological and financial constraints limit restoration efforts, preventing the achievement of desired ecological outcomes. Harvesting invasive plant biomass for bioenergy has the potential to reduce feedback mechanisms that sustain invasion, while alleviating financial limitations. Typha × glauca is a highly productive invasive wetland plant that reduces plant diversity, alters ecological functioning, its impacts increase with time, and is a suitable feedstock for bioenergy. We sought to determine ecological effects of Typha utilization for bioenergy in a Great Lakes coastal wetland by testing plant community responses to harvest-restoration treatments in stands of two age classes and assessing community resilience through a seed bank study. Belowground harvesting increased light penetration, diversity, and richness, and decreased Typha dominance and biomass in both years post-treatment. Aboveground harvesting increased light and reduced Typha biomass in post-year 1 and in post-year 2, increased diversity and richness and decreased Typha dominance. Seed bank analysis revealed that young stands (30 years). In the field, stand-age did not affect diversity or Typha dominance, but old stands had greater Typha biomass and slightly higher richness following harvest. Harvesting Typha achieved at least two desirable ecological outcomes: reducing Typha dominance and increasing native plant diversity. Younger stands had greater potential for native recovery, indicated by more diverse seed banks. In similar degraded wetlands, a single harvest of Typha biomass would likely result in significant biodiversity and habitat improvements, with the potential to double plant species richness

Mechanical Harvesting Effectively Controls Young Typha spp. Invasion and Unmanned Aerial Vehicle Data Enhances Post-treatment Monitoring

The ecological impacts of invasive plants increase dramatically with time since invasion. Targeting young populations for treatment is therefore an economically and ecologically effective management approach, especially when linked to post-treatment monitoring to evaluate the efficacy of management. However, collecting detailed field-based post-treatment data is prohibitively expensive, typically resulting in inadequate documentation of the ecological effects of invasive plant management. Alternative approaches, such as remote detection with unmanned aerial vehicles (UAV), provide an opportunity to advance the science and practice of restoration ecology. In this study, we sought to determine the plant community response to different mechanical removal treatments to a dominant invasive wetland macrophyte (Typha spp.) along an age-gradient within a Great Lakes coastal wetland. We assessed the post-treatment responses with both intensive field vegetation and UAV data. Prior to treatment, the oldest Typha stands had the lowest plant diversity, lowest native sedge (Carex spp.) cover, and the greatest Typha cover. Following treatment, plots that were mechanically harvested below the surface of the water differed from unharvested control and above-water harvested plots for several plant community measures, including lower Typha dominance, lower native plant cover, and greater floating and submerged aquatic species cover. Repeated-measures analysis revealed that above-water cutting increased plant diversity and aquatic species cover across all ages, and maintained native Carex spp. cover in the youngest portions of Typha stands. UAV data revealed significant post-treatment differences in normalized difference vegetation index (NDVI) scores, blue band reflectance, and vegetation height, and these remotely collected measures corresponded to field observations. Our findings suggest that both mechanically harvesting the above-water biomass of young Typha stands and harvesting older stands below-water will promote overall native community resilience, and increase the abundance of the floating and submerged aquatic plant guilds , which are the most vulnerable to invasions by large macrophytes. UAV’s provided fast and spatially expansive data compared to field monitoring, and effectively measured plant community structural responses to different treatments. Study results suggest pairing UAV flights with targeted field data collection to maximize the quality of post-restoration vegetation monitoring

Typha (Cattail) Invasion in North American Wetlands: Biology, Regional Problems, Impacts, Ecosystem Services, and Management

Typha is an iconic wetland plant found worldwide. Hybridization and anthropogenic disturbances have resulted in large increases in Typha abundance in wetland ecosystems throughout North America at a cost to native floral and faunal biodiversity. As demonstrated by three regional case studies, Typha is capable of rapidly colonizing habitats and forming monodominant vegetation stands due to traits such as robust size, rapid growth rate, and rhizomatic expansion. Increased nutrient inputs into wetlands and altered hydrologic regimes are among the principal anthropogenic drivers of Typha invasion. Typha is associated with a wide range of negative ecological impacts to wetland and agricultural systems, but also is linked with a variety of ecosystem services such as bioremediation and provisioning of biomass, as well as an assortment of traditional cultural uses. Numerous physical, chemical, and hydrologic control methods are used to manage invasive Typha, but results are inconsistent and multiple methods and repeated treatments often are required. While this review focuses on invasive Typha in North America, the literature cited comes from research on Typha and other invasive species from around the world. As such, many of the underlying concepts in this review are relevant to invasive species in other wetland ecosystems worldwide

Reconstructing plant invasions using historical aerial imagery and pollen core analysis: T ypha in the L aurentian G reat L akes

Aim Determining the spatial‐temporal spread of an invasive plant is vital for understanding long‐term impacts. However, invasions have rarely been directly documented given the resources required and the need for substantial foresight. One method widely used is historical photography interpretation, but this can be hard to verify. We attempt to improve this method by linking historical aerial photos to a paleobotanical analysis of pollen cores. Location Laurentian G reat L akes coastal wetlands, U nited S tates of A merica. Methods We chose invasive cattail ( T ypha ) as our model species because it is identifiable from aerial imagery and has persistent, identifiable pollen, and its ecological impacts appear to be time‐dependent. We used G eographic I nformation S ystems, aerial photo‐interpretation and field verification to post‐dict the invasion history of T ypha in several wetland ecosystems. Using 210 P b and 137 C s sediment dating and pollen classification, we correlated the temporal dominance of T ypha to our estimates of per cent coverage at one site. The pollen record was then used to estimate the T ypha invasion dynamics for dates earlier than those for which aerial photos were available. Results Typha spread through time in all study wetlands. Typha pollen dominance increased through time corresponding with increased spatial dominance. Hybrid cattail, T .  ×  glauca increased in pollen abundance relative to T . angustifolia pollen through time. Main conclusions This study illustrates the value of generating historical invasion maps with publically available aerial imagery and linking these maps with paleobotanical data to study recent (< 100 years) invasions. We determined rates of T ypha expansion in two coastal wetland types, validated our mapping methods and modelled the relationship between pollen abundance and wetland coverage, enhancing the temporal precision and breadth of analyses. Our methodology should be replicable with similar invasive plant species. The combination of pollen records and historical photography promises to be a valuable additional tool for determining invasion dynamics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94878/1/ddi929.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/94878/2/ddi929-sup-0001-FigureS1.pd

AlbertDennisHorticultureBiomassHarvestInvasiveTypha(SupplementaryTables1-2).pdf

Ecological and financial constraints limit restoration efforts, preventing the achievement of desired ecological outcomes. Harvesting invasive plant biomass for bioenergy has the potential to reduce feedback mechanisms that sustain invasion, while alleviating financial limitations. Typha × glauca is a highly productive invasive wetland plant that reduces plant diversity, alters ecological functioning, its impacts increase with time, and is a suitable feedstock for bioenergy. We sought to determine ecological effects of Typha utilization for bioenergy in a Great Lakes coastal wetland by testing plant community responses to harvest-restoration treatments in stands of two age classes and assessing community resilience through a seed bank study. Belowground harvesting increased light penetration, diversity, and richness, and decreased Typha dominance and biomass in both years post-treatment. Aboveground harvesting increased light and reduced Typha biomass in post-year 1 and in post-year 2, increased diversity and richness and decreased Typha dominance. Seed bank analysis revealed that young stands (30 years). In the field, stand-age did not affect diversity or Typha dominance, but old stands had greater Typha biomass and slightly higher richness following harvest. Harvesting Typha achieved at least two desirable ecological outcomes: reducing Typha dominance and increasing native plant diversity. Younger stands had greater potential for native recovery, indicated by more diverse seed banks. In similar degraded wetlands, a single harvest of Typha biomass would likely result in significant biodiversity and habitat improvements, with the potential to double plant species richness.Keywords: Hybrid cattail, Biodiversity, Seed bank, Biomass energy, Lake Huron, ConservationKeywords: Hybrid cattail, Biodiversity, Seed bank, Biomass energy, Lake Huron, ConservationKeywords: Hybrid cattail, Biodiversity, Seed bank, Biomass energy, Lake Huron, ConservationKeywords: Hybrid cattail, Biodiversity, Seed bank, Biomass energy, Lake Huron, Conservatio

Field-based measurement tools to distinguish clonal Typha taxa and estimate biomass: a resource for conservation and restoration

Two species of clonal Typha [T. latifolia (native) and T. angustifolia (exotic)] hybridize to form the highly invasive, heterotic (high vigor) T. × glauca in North American wetlands leading to increased primary production, litter accumulation, and biodiversity loss. Conservation of T. latifolia has become critical as invasive Typha has overwhelmed wetlands. In the field, Typha taxa identification is difficult due to subtle differences in morphology, and molecular identification is often unfeasible for managers. Furthermore, improved methods to non-destructively estimate Typha biomass is imperative to enhance ecological impact assessments. To address field-based Typha ID limitations, our study developed a predictive model from 14 Typha characters in 7 northern Michigan wetlands to accurately distinguish Typha taxa (n = 33) via linear discriminant analysis (LDA) of molecularly identified specimens. In addition, our study developed a partial least squares regression (PLS) model to predict Typha biomass from field collected measurements (n = 75). Results indicate that two field measurements [Leaf Counts, Longest Leaf] can accurately differentiate the three Typha taxa and advanced-generation hybrids. The LDA model had a 100% correct prediction rate of T. latifolia. The selected PLS biomass prediction model (sqrt[Typha Dry Mass] ~ log[Ramet Area at 30 cm] + Inflorescence Presence + Total Ramet Height + sqrt[Organic Matter Depth]) improved upon existing simple linear regression (SLR) height-to-biomass predictions. The rapid field-based Typha identification and biomass assessment tools presented in this study advance targeted management for regional conservation of T. latifolia and ecological restoration of wetlands impacted by invasive Typha taxa

AlbertDennisHorticultureBiomassHarvestInvasiveTypha.pdf

Ecological and financial constraints limit restoration efforts, preventing the achievement of desired ecological outcomes. Harvesting invasive plant biomass for bioenergy has the potential to reduce feedback mechanisms that sustain invasion, while alleviating financial limitations. Typha × glauca is a highly productive invasive wetland plant that reduces plant diversity, alters ecological functioning, its impacts increase with time, and is a suitable feedstock for bioenergy. We sought to determine ecological effects of Typha utilization for bioenergy in a Great Lakes coastal wetland by testing plant community responses to harvest-restoration treatments in stands of two age classes and assessing community resilience through a seed bank study. Belowground harvesting increased light penetration, diversity, and richness, and decreased Typha dominance and biomass in both years post-treatment. Aboveground harvesting increased light and reduced Typha biomass in post-year 1 and in post-year 2, increased diversity and richness and decreased Typha dominance. Seed bank analysis revealed that young stands (30 years). In the field, stand-age did not affect diversity or Typha dominance, but old stands had greater Typha biomass and slightly higher richness following harvest. Harvesting Typha achieved at least two desirable ecological outcomes: reducing Typha dominance and increasing native plant diversity. Younger stands had greater potential for native recovery, indicated by more diverse seed banks. In similar degraded wetlands, a single harvest of Typha biomass would likely result in significant biodiversity and habitat improvements, with the potential to double plant species richness.Keywords: Hybrid cattail, Seed bank, Lake Huron, Conservation, Biomass energy, BiodiversityKeywords: Hybrid cattail, Seed bank, Lake Huron, Conservation, Biomass energy, Biodiversit