Geology topics

Kyle Doherty

Publications and source records attributed to Kyle Doherty.

3 recordsLinked to original sources

USGS2026

The next generation of products and methodologies to establish biocrusts in degraded ecosystems

Biological soil crusts (biocrusts) – thin, coherent soil surface layers aggregated and inhabited by communities of tiny photoautotrophic and heterotrophic organisms – support ecosystem functioning in drylands and influence the Earth system. Biocrust loss due to disturbance, global change and land use leads to altered hydrological function, susceptibility to erosion and diminished biogeochemical cycling, with consequences extending to regional and global environmental quality and ecosystem service provisioning. To restore degraded drylands, specific techniques could inform how to 1. produce biocrust biota ex situ for use as an inoculum in degraded environments and then 2. encourage the establishment of the inoculum in high-stress environments. To re-establish lost biocrusts, a promising pathway could be the integration of adding biocrust biota (inoculation), ensuring that it stays where applied (retention) and softening environmental stresses and limitations (amelioration) at approximately the same time. Several techniques, most of them developed in only the past few years, demonstrate this integration: biocrust sods, cloths, pellets, capsules and slurries. Biocrust sods are fabric-reinforced patches of biocrust growing on soil, produced in farms and transported to and deployed intact in field sites. Biocrust cloths are fabrics and sheets with biocrust biota grown directly on their surface in greenhouse-based fog chambers that can be attached to soil in the field. Biocrust pellets are small, protective pieces of a binder material (often clay) infused with biocrust inoculum. Biocrust capsules are biodegradable gel capsules filled with biocrust inoculum, often with protective substances. Both pellets and capsules are broadcast over degraded soils. Biocrust slurries are semi-liquid suspensions of biocrust inoculum and other solids that are sprayed or spread in degraded sites. Emerging techniques like these have the potential to restore highly functional drylands and their ecosystem services. Potential applications include ecological restoration of dryland areas disturbed by fire, overgrazing, agriculture, mining and other factors or environmental engineering in other contexts such as cultural heritage sites, croplands or human infrastructure. The next-generation techniques for biocrust restoration described here are tools that could be applied to solve small- to medium-scaled challenges now and with increased production efficiency and informed, strategic use of the products, large-scaled challenges in the future.

Drylands↗

USGS2017

Matching seed to site by climate similarity: techniques to prioritize plant materials development and use in restoration

Land management agencies are increasing the use of native plant materials for vegetation treatments to restore ecosystem function and maintain natural ecological integrity. This shift toward the use of natives has highlighted a need to increase the diversity of materials available. A key problem is agreeing on how many, and which, new accessions should be developed. Here we describe new methods that address this problem. Our methods use climate data to calculate a climate similarity index between two points in a defined extent. This index can be used to predict relative performance of available accessions at a target site. In addition, the index can be used in combination with standard cluster analysis algorithms to quantify and maximize climate coverage (mean climate similarity), given a modeled range extent and a specified number of accessions. We demonstrate the utility of this latter feature by applying it to the extents of 11 western North American species with proven or potential use in restoration. First, a species-specific seed transfer map can be readily generated for a species by predicting performance for accessions currently available; this map can be readily updated to accommodate new accessions. Next, the increase in climate coverage achieved by adding successive accessions can be explored, yielding information that managers can use to balance ecological and economic considerations in determining how many accessions to develop. This approach identifies sampling sites, referred to as climate centers, which contribute unique, complementary, climate coverage to accessions on hand, thus providing explicit sampling guidance for both germplasm preservation and research. We examine how these and other features of our approach add to existing methods used to guide plant materials development and use. Finally, we discuss how these new methods provide a framework that could be used to coordinate native plant materials development, evaluation, and use across agencies, regions, and research groups.

Ecological Applications↗

USGS2015

Production of greenhouse-grown biocrust mosses and associated cyanobacteria to rehabilitate dryland soil function

Mosses are an often-overlooked component of dryland ecosystems, yet they are common members of biological soil crust communities (biocrusts) and provide key ecosystem services, including soil stabilization, water retention, carbon fixation, and housing of N 2 fixing cyanobacteria. Mosses are able to survive long dry periods, respond rapidly to precipitation, and reproduce vegetatively. With these qualities, dryland mosses have the potential to be an excellent dryland restoration material. Unfortunately, dryland mosses are often slow growing in nature, and ex situ cultivation methods are needed to enhance their utility. Our goal was to determine how to rapidly produce, vegetatively, Syntrichia caninervis and S. ruralis , common and abundant moss species in drylands of North America and elsewhere, in a greenhouse. We manipulated the length of hydration on a weekly schedule (5, 4, 3, or 2 days continuous hydration per week), crossed with fertilization (once at the beginning, monthly, biweekly, or not at all). Moss biomass increased sixfold for both species in 4 months, an increase that would require years under dryland field conditions. Both moss species preferred short hydration and monthly fertilizer. Remarkably, we also unintentionally cultured a variety of other important biocrust organisms, including cyanobacteria and lichens. In only 6 months, we produced functionally mature biocrusts, as evidenced by high productivity and ecosystem-relevant levels of N 2 fixation. Our results suggest that biocrust mosses might be the ideal candidate for biocrust cultivation for restoration purposes. With optimization, these methods are the first step in developing a moss-based biocrust rehabilitation technology.

Restoration Ecology↗