Why are Some Plant Species Missing from Restorations? A Diagnostic Tool for Temperate Grassland Ecosystems

The U.N. Decade on Ecosystem Restoration aims to accelerate actions to prevent, halt, and reverse the degradation of ecosystems, and re-establish ecosystem functioning and species diversity. The practice of ecological restoration has made great progress in recent decades, as has recognition of the importance of species diversity to maintaining the long-term stability and functioning of restored ecosystems. Restorations may also focus on specific species to fulfill needed functions, such as supporting dependent wildlife or mitigating extinction risk. Yet even in the most carefully planned and managed restoration, target species may fail to germinate, establish, or persist. To support the successful reintroduction of ecologically and culturally important plant species with an emphasis on temperate grasslands, we developed a tool to diagnose common causes of missing species, focusing on four major categories of filters, or factors: genetic, biotic, abiotic, and planning & land management. Through a review of the scientific literature, we propose a series of diagnostic tests to identify potential causes of failure to restore target species, and treatments that could improve future outcomes. This practical diagnostic tool is meant to strengthen collaboration between restoration practitioners and researchers on diagnosing and treating causes of missing species in order to effectively restore them

Remote sensing tools for the large-scale monitoring of vegetation dynamics in wetland ecosystems

Continued worldwide urban and agricultural expansion has triggered a loss and degradation of wetland resources. The United States alone seen a 50% decline in its wetland extent, with this percentage reaching a staggering 70% in certain states. With this widespread fragmentation and degradation of habitats, fewer sites are left with the important role of providing ecosystem services critical to the well-being of human populations. A thorough monitoring of wetland resources is necessary for rapidly identifying areas that require adaptive management and for best allocating limited conservation resources. This dissertation explores different methodological approaches for the large-scale monitoring of wetland ecosystems at low cost using open source remote sensing data. The first chapter provides a review of current monitoring practices in restored wetlands of the San Francisco estuary, California, USA. It identifies opportunities to leverage geospatial tools and datasets, including remote sensing products, to measure the contribution of individual restoration efforts towards regional wetland conservation goals. The second chapter examines the response of landscape metrics characterizing the distribution, size, and shape of vegetated patches to vegetation dynamics in a subset of restored wetlands and reference sites in the Sacramento-San Joaquin Delta of California. To portray vegetation response to restoration treatments, this chapter leverages high resolution aerial images from the National Agriculture Inventory Program and a collection of bi-monthly satellite images from the Landsat archives. The third chapter studies changes in the phenology of wetland sites throughout a 17-year period to identify phenological metrics most responsive to restoration interventions. This chapter outlines the impact of site characteristics and vegetation dynamics on landscape phenology. Finally, the fourth chapter uses a broader scale of analysis to examine how vegetation structure, composition, and spatial distribution modulate wetland greenness as measured by spectral vegetation indices derived from satellite data. By examining the relationships between field properties and spectral greenness across 1,138 wetlands of the conterminous United States, this chapter identifies the spectral vegetation indices most suited for wetland monitoring across different wetland types, vegetation densities, and disturbance levels

Remote sensing tools for the large-scale monitoring of vegetation dynamics in wetland ecosystems

Continued worldwide urban and agricultural expansion has triggered a loss and degradation of wetland resources. The United States alone seen a 50% decline in its wetland extent, with this percentage reaching a staggering 70% in certain states. With this widespread fragmentation and degradation of habitats, fewer sites are left with the important role of providing ecosystem services critical to the well-being of human populations. A thorough monitoring of wetland resources is necessary for rapidly identifying areas that require adaptive management and for best allocating limited conservation resources. This dissertation explores different methodological approaches for the large-scale monitoring of wetland ecosystems at low cost using open source remote sensing data. The first chapter provides a review of current monitoring practices in restored wetlands of the San Francisco estuary, California, USA. It identifies opportunities to leverage geospatial tools and datasets, including remote sensing products, to measure the contribution of individual restoration efforts towards regional wetland conservation goals. The second chapter examines the response of landscape metrics characterizing the distribution, size, and shape of vegetated patches to vegetation dynamics in a subset of restored wetlands and reference sites in the Sacramento-San Joaquin Delta of California. To portray vegetation response to restoration treatments, this chapter leverages high resolution aerial images from the National Agriculture Inventory Program and a collection of bi-monthly satellite images from the Landsat archives. The third chapter studies changes in the phenology of wetland sites throughout a 17-year period to identify phenological metrics most responsive to restoration interventions. This chapter outlines the impact of site characteristics and vegetation dynamics on landscape phenology. Finally, the fourth chapter uses a broader scale of analysis to examine how vegetation structure, composition, and spatial distribution modulate wetland greenness as measured by spectral vegetation indices derived from satellite data. By examining the relationships between field properties and spectral greenness across 1,138 wetlands of the conterminous United States, this chapter identifies the spectral vegetation indices most suited for wetland monitoring across different wetland types, vegetation densities, and disturbance levels

Spatially explicit tools to assess invasion risks by Phragmites australis in freshwater wetlands

The rapid progression of an exotic haplotype of common reed (Phragmites australis (Cav.) Trin. ex Steud.) in North America is associated with a decline in the plant diversity of wetlands and possibly threatens native haplotypes of Phragmites australis. As prevention is a better strategy than control, a spatially-explicit approach was developed to predict the risk of invasion by the exotic P. australis and its potential impact on a native haplotype. Focusing on a protected wetland of Quebec, Canada where the two haplotypes occur, this study specifically aimed to: 1) compare and contrast the current spatial distribution of the two haplotypes in relation to landscape and land use/land cover variables, and 2) predict, using spatially-explicit models, the potential expansion patterns of the exotic and native P. australis. Results showed that the native P. australis was currently more frequent than the exotic P. australis. At this stage of invasion, native and exotic P. australis still occupied distinct parts of the territory, the native one being associated more with low marsh and areas of lesser human impacts, the exotic one being closer to roads or associated with drier land covers. Perturbations to the natural environment provided invasion foci for the exotic P. australis which is more tolerant to disturbances than the native one. The current distribution of invasion foci of exotic P. australis and its association to a broad range of conditions resulted in predicted expansion patterns where the cover of the exotic P. australis could potentially surpass the cover of the native P. australis within 10 years. This could lower the conservation value of the protected wetland and increase the competition with native colonies of P. australis where the two haplotypes intersect.La progression d'un haplotype exotique du roseau commun (Phragmites australis (Cav.) Trin ex Steud.) en Amérique du nord réduit la diversité végétale des milieux humides en plus de menacer les haplotypes indigènes de Phragmites australis. La prévention étant plus efficace que le contrôle, une approche spatialement explicite visant à prédire les risques d'invasion par l'haplotype exotique et son impact sur un haplotype indigène a été développée. Cette étude conduite dans un marais protégé du Québec (Canada) visait à : 1) comparer et expliquer la distribution spatiale actuelle de ces deux haplotypes sur la base de leur relation à des variables de couverture/utilisation du sol et du paysage et 2) prédire à partir de modèles spatialement explicites les patrons d'expansion futures des haplotypes exotique et indigène de P. australis. À ce stade-ci de l'invasion, les haplotypes occupent des zones distinctes du territoire ; le P. australis indigène est associé aux bas marais et à des zones où l'influence anthropique est faible, tandis que le P. australis exotique se trouve près des routes et dans les milieux plus secs. Les perturbations au milieu naturel constituent des foyers d'invasion propices à l'haplotype exotique qui semble tolérer un éventail de conditions environnementales plus large que l'haplotype indigène. La modélisation des patrons d'expansion de l'haplotype a démontré que celui-ci pourrait surpasser en couverture l'haplotype indigène d'ici 10 ans, en raison de son association à un vaste éventail de conditions environnementales. Cette progression de l'haplotype exotique pourrait réduire la valeur de conservation du milieu humide et intensifier la compétition avec les colonies indigènes de P. australis

Geospatial Tools for the Large-Scale Monitoring of Wetlands in the San Francisco Estuary: Opportunities and Challenges

Significant wetland losses and continuing threats to remnant habitats have motivated extensive restoration efforts in the San Francisco Bay–Delta estuary of California, the largest in the western United States. Consistent monitoring of ecological outcomes from this restoration effort would help managers learn from past projects to improve the design of future endeavors. However, budget constraints and challenging field conditions can limit the scope of current monitoring programs. Geospatial tools and remote sensing data sets could help complement field efforts for a low-cost, longer, and broader monitoring of wetland resources. To understand where geospatial tools could best complement current field monitoring practices, we reviewed the metrics and monitoring methods used by 42 wetland restoration projects implemented in the estuary. Monitoring strategies within our sample of monitoring plans relied predominantly on field surveys to assess key aspects of vegetation recovery while geospatial data sets were used sparingly. Drawing on recent publications that focus on the estuary and other wetland systems, we propose additional geospatial applications to help monitor the progress made toward site-specific and regional goals. These include the use of ecological niche models to target on-the-ground monitoring efforts, the up-scaling of field measurements into regional estimates using remote sensing data, and the analysis of time-series to detect ecosystem shifts. We discuss challenges and limitations to the broad-scale application of remote sensing data in wetland monitoring. These notably include the need to find a venue to store and share computationally intensive data sets, the often cumbersome pre-processing effort needed for long-term analyses, and multiple confounding factors that can obscure the signal of remote sensing data sets

Mixed Metal Oxide Nanoparticle Formulations for the Treatment of Seroma.

Seroma formation is a well-recognized postoperative complication for many plastic and general surgical procedures. Although various tissue adhesives and substances have been used in an effort to treat seroma formation, no therapies have been established clinically. Recently, the nano-bridging phenomenon has been introduced as a promising approach to achieve tissue adhesion and strong closure of deep skin wounds in rats. The present study seeks to assess the potential of nano-bridging beyond skin wounds in a rat model of seroma. Seromas were induced in 20 Lewis rats through bilateral axillary lymphadenectomy, excision of the latissimus dorsi and cutaneous maximus muscles, and disruption of dermal lymphatics. On postoperative day (POD) 7, the seroma was aspirated on both sides. A bioactive nanoparticle (NP) suspension based on zinc-doped strontium-substituted bioglass/ceria nanoparticles (NP group) or fibrin glue (fibrin group) was injected into the right seroma cavity, while the left side was left untreated. On POD 14, the NP group showed complete remission (no seromas at all), while the fibrin group recorded a reduction of only 63% in the seroma fluid volume. The NPs exerted local anti-inflammatory and neo-angiogenic effects, without any detectable systemic changes. Moreover, the ceria levels recorded in the organs did not surpass the background level, indicating that the nanoparticles stayed at the site of application. This study is a promising first example demonstrating the ability of inorganic nanoparticle formulations to reduce seroma formation in a rat model, without any detectable systemic adverse effects. These results emphasize the potential of nanotechnological solutions in the therapeutic management of seroma in the clinical setting

Remotely sensed phenological heterogeneity of restored wetlands: linking vegetation structure and function

Seasonal phenological dynamics of vegetation hold important clues on ecosystem performance towards management goals, such as carbon uptake, and thus should be considered in projections of their targeted services. However, in wetlands spatio-temporal heterogeneity due to mixing of open water, soil, green and dead vegetation makes it difficult to generalize ecosystem functioning across different regions. Remote sensing observations can provide spatially-explicit, cost-effective phenology indicators; however, little is known about their capacity to indicate the links between wetland ecosystem structure and function. Here we assessed this potential by comparing one-year Enhanced Vegetation Index (EVI) from satellite products at high (5m; RapidEye) and low (30m; Landsat) spatial resolutions with eddy covariance time series of net carbon exchange, field digital camera (phenocam) greenness and water temperature among three floristically similar restored wetlands in California, USA. Phenological timing differed by wetland site: depending on satellite, the range in site-median start of greening was up to 28 days, end of greening – up to 73 days, start of senescence – up to 79 days, and end of senescence – up to 10 days. Key transition dates from satellite inputs agreed with seasonal changes in net carbon exchange, phenocam greenness and water temperatures, suggesting that phenological contrasts could result in part from site differences in vegetation configuration and litter affecting the exposure of canopy, soil and water to sunlight and thus sub-canopy microclimate and ecosystem functioning. Yet, the agreement between satellite inputs was non-systematic, with the greatest disparities at the more heterogeneous, less vegetated site. Phenological model fitting uncertainty increased with greater spatial resolution, highlighting the tradeoff between the accuracy of representing vegetation and the complexity of local seasonal variation. These findings highlight the sensitivity of satellite-derived phenology to structural and functional heterogeneity of ecosystems and call for more rigorous spatially-explicit analyses to inform assessments of restoration and management outcomes

Mixed Metal Oxide Nanoparticle Formulations for the Treatment of Seroma

Seroma formation is a well-recognized postoperative complication for many plastic and general surgical procedures. Although various tissue adhesives and substances have been used in an effort to treat seroma formation, no therapies have been established clinically. Recently, the nano-bridging phenomenon has been introduced as a promising approach to achieve tissue adhesion and strong closure of deep skin wounds in rats. The present study seeks to assess the potential of nano-bridging beyond skin wounds in a rat model of seroma. Seromas were induced in 20 Lewis rats through bilateral axillary lymphadenectomy, excision of the latissimus dorsi and cutaneous maximus muscles, and disruption of dermal lymphatics. On postoperative day (POD) 7, the seroma was aspirated on both sides. A bioactive nanoparticle (NP) suspension based on zinc-doped strontium-substituted bioglass/ceria nanoparticles (NP group) or fibrin glue (fibrin group) was injected into the right seroma cavity, while the left side was left untreated. On POD 14, the NP group showed complete remission (no seromas at all), while the fibrin group recorded a reduction of only 63% in the seroma fluid volume. The NPs exerted local anti-inflammatory and neo-angiogenic effects, without any detectable systemic changes. Moreover, the ceria levels recorded in the organs did not surpass the background level, indicating that the nanoparticles stayed at the site of application. This study is a promising first example demonstrating the ability of inorganic nanoparticle formulations to reduce seroma formation in a rat model, without any detectable systemic adverse effects. These results emphasize the potential of nanotechnological solutions in the therapeutic management of seroma in the clinical setting

Productive wetlands restored for carbon sequestration quickly become net CO2 sinks with site-level factors driving uptake variability.

Inundated wetlands can potentially sequester substantial amounts of soil carbon (C) over the long-term because of slow decomposition and high primary productivity, particularly in climates with long growing seasons. Restoring such wetlands may provide one of several effective negative emission technologies to remove atmospheric CO2 and mitigate climate change. However, there remains considerable uncertainty whether these heterogeneous ecotones are consistent net C sinks and to what degree restoration and management methods affect C sequestration. Since wetland C dynamics are largely driven by climate, it is difficult to draw comparisons across regions. With many restored wetlands having different functional outcomes, we need to better understand the importance of site-specific conditions and how they change over time. We report on 21 site-years of C fluxes using eddy covariance measurements from five restored fresh to brackish wetlands in a Mediterranean climate. The wetlands ranged from 3 to 23 years after restoration and showed that several factors related to restoration methods and site conditions altered the magnitude of C sequestration by affecting vegetation cover and structure. Vegetation established within two years of re-flooding but followed different trajectories depending on design aspects, such as bathymetry-determined water levels, planting methods, and soil nutrients. A minimum of 55% vegetation cover was needed to become a net C sink, which most wetlands achieved once vegetation was established. Established wetlands had a high C sequestration efficiency (i.e. the ratio of net to gross ecosystem productivity) comparable to upland ecosystems but varied between years undergoing boom-bust growth cycles and C uptake strength was susceptible to disturbance events. We highlight the large C sequestration potential of productive inundated marshes, aided by restoration design and management targeted to maximise vegetation extent and minimise disturbance. These findings have important implications for wetland restoration, policy, and management practitioners