Establishment and Management of Native Functional Groups in Restoration

The limiting similarity hypothesis predicts that communities should be more resistant to invasion by non-natives when they include natives with a diversity of traits from more than one functional group. In restoration, planting natives with a diversity of traits may result in competition between natives of different functional groups and may influence the efficacy of different seeding and maintenance methods, potentially impacting native establishment. We compare initial establishment and first-year performance of natives and the effectiveness of maintenance techniques in uniform versus mixed functional group plantings. We seeded ruderal herbaceous natives, longer-lived shrubby natives, or a mixture of the two functional groups using drill- and hand-seeding methods. Non-natives were left undisturbed, removed by hand-weeding and mowing, or treated with herbicide to test maintenance methods in a factorial design. Native functional groups had highest establishment, growth, and reproduction when planted alone, and hand-seeding resulted in more natives as well as more of the most common invasive, Brassica nigra. Wick herbicide removed more non-natives and resulted in greater reproduction of natives, while hand-weeding and mowing increased native density. Our results point to the importance of considering competition among native functional groups as well as between natives and invasives in restoration. Interactions among functional groups, seeding methods, and maintenance techniques indicate restoration will be easier to implement when natives with different traits are planted separately. © 2013 Society for Ecological Restoration

Plant traits reveal that biotic resistance to invasibility is shaped by slope aspect.

During community assembly, species traits interact with environmental conditions and influence biotic interactions. Learning how traits of non-native species enable them to successfully navigate these interacting biotic and abiotic filters informs invasion dynamics. Here we test how plant traits relate to invasion resistance under differing degrees of abiotic stress based on slope aspect in a large restoration project in Southern California. The site was dominated by non-native annual plants but was restored to coastal sage scrub and grassland with mixtures of native shrubs, grasses, and forbs on two different slope aspects. Abiotic filters may be stronger than biotic filters on slopes exposed to greater solar radiation (S-facing at our study site) resulting in decreased soil moisture and increased abiotic stress. We measured subsequent establishment and performance by the three most abundant non-native species (Brassica nigra in year 1, Salsola tragus and Sonchus oleraceus in year 3) on N- and S-facing slopes to investigate relationships between traits, abiotic environment, native community composition, and invasibility in the context of community assembly. We evaluated which measures of community functional diversity best predicted invader performance and tested whether relationships between invader performance and community-weighted trait values varied by slope aspect. Plots with slow-growing native shrubs contained less of the fast-growing invasive, Brassica nigra. Invasibility was greatest in native communities restored with native grass and on N-facing slopes. Correlations among individual species traits indicated strong biotic filtering, but only in certain environments. For instance, the abundance of Phacelia cicutaria, a native annual with traits similar to Brassica nigra, was negatively correlated with that invasive on N-facing slopes. Community-weighted trait metrics were also related to invasibility and differed by slope aspect, though relationships varied based on specific functional trait, community-weighted trait measure (mean or dispersion), and invader. The native functional group most effective at preventing invasion (native shrubs) was different from the species that most prevented invasion (native forb). In restoration planning, functional groups and individual native species traits may be more predictive of invasion resistance than community-weighted trait metrics. Combining perennials with an under-story of fast-growing annuals worked well to prevent invasion by non-native annuals. Understanding the role of lifespan effects in biotic filtering is essential for interpreting complex community-weighted trait responses to environmental variation across space and time

Coevolution between native and invasive plant competitors: implications for invasive species management

Invasive species may establish in communities because they are better competitors than natives, but in order to remain community dominants, the competitive advantage of invasive species must be persistent. Native species that are not extirpated when highly invasive species are introduced are likely to compete with invaders. When population sizes and genetic diversity of native species are large enough, natives may be able to evolve traits that allow them to co-occur with invasive species. Native species may also evolve to become significant competitors with invasive species, and thus affect the fitness of invaders. Invasive species may respond in turn, creating either transient or continuing coevolution between competing species. In addition to demographic factors such as population size and growth rates, a number of factors including gene flow, genetic drift, the number of selection agents, encounter rates, and genetic diversity may affect the ability of native and invasive species to evolve competitive ability against one another. We discuss how these factors may differ between populations of native and invasive plants, and how this might affect their ability to respond to selection. Management actions that maintain genetic diversity in native species while reducing population sizes and genetic diversity in invasive species could promote the ability of natives to evolve improved competitive ability

Strategic Sharing Workbook: Youth Voice in Advocacy

This workbook is for individuals who have experienced traumatic life experiences and are interested in sharing their stories in an effort to promote change. Training in Strategic Sharing is an important part of advocacy – we encourage anyone who has experienced traumatic life events and wishes to share those experiences in an effort to promote positive changes for yourself and/or others, to do so with the help of this guide. As you will see mentioned several times in this workbook, it is really important that you take the time to take care of yourself. This training was not developed to help anyone overcome aspects of trauma; it was created to help individuals avoid retraumatization when sharing their traumatic experiences with others. So we encourage everyone using this workbook to either continue with your mental health services or to seek out mental health supports. This guide is also meant to help you better convey your message to others. The whole purpose of advocacy is to inspire change on some level. With Strategic Sharing Training, you will be better equipped to do just that. Learning how to safely and effectively share your story will have a lasting impact on individuals and inspire change in not only your life, but in the lives of others

ALBERTO LLERAS CAMARGO, FIRST SECRETARY GENERAL OF THE ORGANIZATION OF AMERICAN STATES: A STUDY OF THE NATURE OF EXECUTIVE LEADERSHIP IN INTERNATIONAL ORGANIZATIONS

Source: Dissertation Abstracts International, Volume: 33-05, Section: A, page: 2466.</p

Establishment and management of native functional groups in restoration

The limiting similarity hypothesis predicts that communities should be more resistant to invasion by non-natives when they include natives with a diversity of traits from more than one functional group. In restoration, planting natives with a diversity of traits may result in competition between natives of different functional groups and may influence the efficacy of different seeding and maintenance methods, potentially impacting native establishment. We compare initial establishment and first-year performance of natives and the effectiveness of maintenance techniques in uniform versus mixed functional group plantings. We seeded ruderal herbaceous natives, longer-lived shrubby natives, or a mixture of the two functional groups using drill- and hand-seeding methods. Non-natives were left undisturbed, removed by hand-weeding and mowing, or treated with herbicide to test maintenance methods in a factorial design. Native functional groups had highest establishment, growth, and reproduction when planted alone, and hand-seeding resulted in more natives as well as more of the most common invasive, Brassica nigra. Wick herbicide removed more non-natives and resulted in greater reproduction of natives, while hand-weeding and mowing increased native density. Our results point to the importance of considering competition among native functional groups as well as between natives and invasives in restoration. Interactions among functional groups, seeding methods, and maintenance techniques indicate restoration will be easier to implement when natives with different traits are planted separately. © 2013 Society for Ecological Restoration