Daniela Shebitz

Evaluating the Purpose, Extent, and Ecological Restoration Applications of Indigenous Burning Practices in Southwestern Washington

Understanding the historic fire regime is essential before restoring fire to an ecosystem. Historical ecology provides a means to use both quantitative and qualitative data from different disciplines to address questions about how the traditional ecological management (TEM) practices of indigenous peoples influenced prairie and savanna ecosystems in the past. In this article, we evaluated paleoecological, archaeological, ethnographic, and ethnobotanical information about the Upper Chehalis River basin prairies of southwestern Washington to better understand the extent to which TEM influenced prairie distribution, composition, and availability of wild plant food resources. We also surveyed areas that had been burned at differing frequencies to test whether frequent fires increase camas (Camassia quamash) productivity. Preliminary results support the hypothesis that camas productivity increases with fire-return intervals of one to two years.

Weaving Traditional Ecological Knowledge into the Restoration of Basketry Plants

This paper focuses on the benefits of incorporating traditional ecological knowledge into the field of ecological restoration. Case studies on indigenous use of sweetgrass in New York State, U.S.A (Haudenosaunee Nation), and beargrass in Washington State, U.S.A (Quinault and Skokomish Nations), are presented. Both studies focus on the restoration of basketry plants by incorporating indigenous knowledge of changes in abundance of culturally significant plants; knowledge of sites appropriate for restoration of culturally significant plants; and knowledge of land management methods to restore species and/or habitats. Open-ended, semi-formal, and informal interviews were conducted with indigenous consultants familiar with the plant and/or habitat of interest. Traditional knowledge of appropriate restoration sites was used in a field experiment to re-establish sweetgrass in an area from which it is believed to have been extirpated. Traditional knowledge of anthropogenic burning was used to reintroduce fire in low-elevation beargrass habitats to manage both the resource and its environment. By incorporating traditional knowledge with published information on sweetgrass biology, it was found that two potential factors influencing its population in cultural gathering sites are unsustainable harvesting and the absence of controlled burns.

Ecological and Cultural Significance of Burning Beargrass Habitat on the Olympic Peninsula, Washington

To conserve or restore culturally significant plants, one must consider the important role that indigenous land management techniques have played in maintaining habitats of those species. Beargrass (Xerophyllum tenax) is a basketry plant used by Native Americans and is reportedly declining in traditional gathering sites. Many low-elevation beargrass sites on the Olympic Peninsula in Washington were maintained as savannas and wetland prairies through anthropogenic burning prior to European settlement. This study measures short-term (1 and 2 y) effects of reintroducing prescribed burning (both low and high severity) and manual clearing on beargrass growth and reproductive success—flowering, vegetative reproduction, and seedling establishment. High-severity fire led to a significant increase in beargrass seedling establishment and vegetative reproduction over two years but a decline in beargrass cover. Low-severity fire also decreased beargrass cover, but did not significantly affect shoot production or seedling establishment. In areas where vegetation and coarse woody debris were manually cleared, beargrass cover decreased, while shoot production and flowering increased. Neither low-severity fires nor clearing plots affected beargrass seedling establishment. Results indicate that fire is a useful tool for enhancing low-elevation beargrass populations in this region.

Beargrass (Xerophyllum tenax) on the Olympic Peninsula, Washington: Autecology and Population Status

We studied the autecology and population status of beargrass (Xerophyllum tenax (Pursh) Nutt.) on the Olympic Peninsula of Washington State, focusing in the Olympic National Forest (ONF). Objectives were to: (1) define and describe beargrass habitat types in the ONF through an exploratory field study, and (2) determine whether beargrass populations in the ONF have declined where the species was historically present. We found three distinct beargrass habitat types in on the ONF: western low elevation, eastern low elevation, and high elevation habitats. These habitat types significantly differ in elevation, slope, topographic moisture, vegetation cover, successional stage, and litter layer thickness. We suggest environmental conditions of these habitat types may be attributed to the glacial and cultural history of the Olympic Peninsula. Beargrass cover in previously established plots on the southeastern Olympic Peninsula declined over the past 17 years, perhaps due to harvesting for the floral industry and an increase in canopy cover due to the absence of natural and anthropogenic burning. Our methods and findings may apply to other Northwestern species.

Forest Structure, Nutrients, and Pentaclethra macroloba Growth after Deforestation of Costa Rican Lowland Forests

Succession following deforestation in Neotropical forests has been investigated extensively, yet rarely have studies connected nutrient dynamics with vegetation. This study was conducted in lowland wet forests of Maquenque, Costa Rica. The objectives were (1) to compare carbon (C), nitrogen (N), and phosphorus (P) characteristics and understory vegetation diversity between regenerating forests and primary forests; and (2) to use these variables to evaluate P. macroloba’s successional role. Four 300 m2 plots were established in primary and secondary forests where P. macroloba was the dominant N-fixing tree. Soil and vegetation data were collected from 2008 to 2010. Values of indicators of C, N, and P cycle activity were generally greater in primary than in secondary forest soils. Efficiency of organic C use and the relative contribution of respiration and organic C to soil biomass were also greater in the primary forest. These trends corresponded with greater richness, biomass, and cover of total and leguminous plant species, greater volume of P. macroloba in primary stands, and greater density of P. macroloba in secondary stands. As cleared regions of former primary forest regenerate, P. macroloba is the important dominant N-fixing tree and a critical driver of C, N, and P recuperation and ecosystem recovery.

Preliminary observations of using smoke-water to increase low-elevation Beargrass Xerophyllum tenax germination

Through a greenhouse experiment, we found that smoke-water can be an effective restoration tool in germinating bear-grass (Xerophyllum tenax (Pursh) Nutt. [Liliaceae]) seeds. We studied the effects of smoke-water on germination rates of beargrass seeds collected from low-elevation dry forests of the southeastern Olympic Peninsula of Washington State and from a wetland of the western Peninsula. Seeds received a treatment of either smoke-water or tap water (the control), which was followed by a cold stratification treatment for 0, 8, 10, 12, 14, or 16 wk. The highest success of beargrass seed germination resulted from seeds collected from the wetland habitat being exposed to smoke-water prior to undergoing 14 wk of cold stratification. This study supports the use of smoke technology in restoration when the reintroduction of burning is not feasible.

The Effects of the N-Fixing Tree Pentaclethra macroloba on the Above and Below Ground Communities Within a Primary Forest in the Northern Zone of Costa Rica

The soil microbial community is not only critical to nutrient recycling and mineralization of organic material, but also plays a fundamental role in influencing plant community composition (Kent & Triplett 2002, Buckley & Schmidt 2003, Leininger et al. 2006, Wardle et al. 2004, Ibekwe et al. 2007, Fierer et al. 2007, Litton & Giardina 2008). Conversely, differences in vegetation community also affect the soil fungal and bacterial composition, which then drives the decomposition and nutrient cycle processes. For example, a complex relationship exists between vegetation-derived carbohydrates, lignin, soil inorganic N, increased soil complexity and microbial community development that affects the soil organic C levels and productivity (Guggenberger et al. 1994, Zech and Kogel-Knaber 1994, Brookes 1995, Anderson 2003, He et al. 2003, Moscatelli et al. 2005, Bradford et al. 2008). Furthermore, increases in soil inorganic N stimulate increased production of more labile root-derived carbohydrates by plants which are used by the bacterial community, while preliminary plant decomposition selects for fungi which degrade the lignin, cellulose, hemicelluloses, and other complex materials (Guggenberger et al. 1994, 1995; Padmanabhan et al. 2003; de Boer et al. 2005; Fierer et al. 2007; Bradford et al. 2008; Talbot et al. 2008). Thus, it is the fungi that decompose more complex organic substrates more efficiently than bacteria leaving behind more recalcitrant residues and enhancing the organic carbon matter in the soil, and are more important as decomposers in older or restored soils (Holland and Coleman, 1987, Bardgett et al. 1993, Cambardella and Elliot 1994, Guggenberger et al. 1994, 1995, 1999; Beare 1997, Bardgett and McAlister 1999; Stahl et al. 1999, Griffith and Bardgett 2000, Zeller et al. 2001; Bailey et al. 2002, Talbot et al 2008). The soil bacteria, on the other hand, are more critical in decomposition and N nutrient cycling in managed, young, or recovering ecosystems (Moore and de Ruiter 1991, Lovell et al. 1995).

Undergraduate Learning from the Ground Up: Linking Belowground and Aboveground Diversity in Costa Rica

Through a grant from the National Science Foundation’s Research Experiences for Undergraduates (NSF REU), 24 undergraduates (more than half from underrepresented demographic groups) addressed ecological and natural resource management questions within the Maquenque National Wildlife Refuge between 2013 and 2015. Students worked with faculty mentors and researched vegetation, invertebrates, primates, soil microbial community structures, or soil biogeochemical characteristics within a variety of undamaged, damaged, or at-risk habitats. This article highlights some studies conducted by students that sought to provide new ecological information to Costa Rica’s Research and Monitoring Plan. Development and diversity are compared within a variety of sites, including selectively harvested forests, 10to 30-year-old regenerating secondary forests, silviculture plots, and recent agriculture sites that were left fallow. Outcomes in student learning, scientific growth, and ability to connect personal research to that of others are presented. The research experience encouraged the students to become scientists with a global perspective in ecology and environmental sciences, and provided data that can be used for future land management and educational purposes.