How do species interactions drive community re-assembly of banksia woodlands?

Degraded land is a major issue globally and impacts human societies on every inhabited continent. To counter the negative effects of land degradation and return ecosystems to reference ecological states, active restoration is often required. However, many restoration efforts suffer from low success in the re-assembly of reference states. As such, there is a need for improvements on current restoration practices. Ecological theory suggests that early plant colonisers could help later arrivals in re-assembly. This theory has the potential to inform restoration efforts. The major goal of my research is to build on current theoretical understanding of plant-plant interactions while at the same time improving restoration practice for banksia woodlands. My study system offers a great test of my ideas because it is highly biodiverse. A greater understanding of plant-plant interactions in space, and interactions between diverse functional groups, will inform the types of species to include in seed mixes and could potentially improve likelihoods of restoration success in other woody ecosystems around the world. Specifically, I used observational and manipulative experiments to test spatial arrangements of plant species and build on theories of plant-plant interactions in early and mid-successional stages of restoration. I tracked re-assembly of banksia woodland after sand mining on the Swan Coastal Plain. I utilized spatial point pattern analysis in two studies to analyse spatial associations of perennial plant species and infer interactions from spatial arrangement. Utilizing knowledge gained from the first two studies, I manipulated the spatial arrangement of seeds to test differences in seedling survival. Finally, I tested different densities of a fire-ephemeral species that could impact survival of seedlings in restoration. Results of my studies demonstrate that plant-plant interactions play a critical role in the survival of some species and spatial arrangement effects restoration outcomes. I found some species have a greater tendency to demonstrate positive interactions, but the strength of positive and negative interactions changes through time and by species. Similarly, density dependent mortality was strong for some species but not others. The spatial arrangement of species was also important to seedling survival. Four of six species had greater survival in concentrated seeding-bare space configurations than completely random dispersed plantings, which are representative of current restoration practices. Few studies of positive plant-plant interactions exist for Australia and my studies demonstrate that both positive and negative interactions drive re-assembly patterns in restoration. A greater understanding of plant-plant interactions in space, and interactions between diverse functional groups, will inform the types of species to include in seed mixes and seeding spatial arrangements. Utilizing spatially-informed restoration practices could improve likelihoods of restoration success in other woody ecosystems around the world

Anaho Island, Nevada: A Relict Area Dominated by Annual Invader Species

This material was digitized as part of a cooperative project between the Society for Range Management, the National Agricultural Library, and the University of Arizona Libraries.The Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform March 202

Seasonal forage production and quality on four native and improved plant communities in Eastern Oregon

Seasonal trends in forage quality and production were studied on improved and unimproved portions of four plant communities in eastern Oregon. The range improvements consisted of seeding and/or thinning. Improvement doubled forage production on the lodgepole pine site (thinned but not seeded), tripled production on the grassland and moist meadow sites (both seeded), and caused a sixfold rise in forage production on the mixed conifer site (thinned and seeded). However, only in the case of the grassland did range improvement lengthen the period when forage provided adequate nutrition for growth of yearling cattle; the improved nutrition can be attributed primarily to inclusion of a legume (alfalfa) in the seeding mixture. On the forested sites, thinning tended to cause forage to mature earlier and thus decline in forage quality faster than on unthinned controls.Published September 1985. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalo

Western Juniper Field Guide: Asking the Right Questions to Select Appropriate Management Actions

Strong evidence indicates that western juniper has significantly expanded its range since the late 1800s by encroaching into landscapes once dominated by shrubs and herbaceous vegetation (fig. 1). Woodland expansion affects soil resources, plant community structure and composition, water, nutrient and fire cycles, forage production, wildlife habitat, and biodiversity. Goals of juniper management include an attempt to restore ecosystem function and a more balanced plant community that includes shrubs, grasses, and forbs, and to increase ecosystem resilience to disturbances. Developing a management strategy can be a difficult task due to uncertainty about how vegetation, soils, hydrologic function, and wildlife will respond to treatments. When developing a management strategy, the first and possibly most important step towards success is asking the right questions. Identifying the attributes of the area to be treated and selecting the right treatments to be applied are of utmost importance. One must ask questions addressing the kind of site (that is, potential natural vegetation, soils, etc.), the current state of the site (that is, successional, hydrologic, etc.), what components need to be restored, how the management unit fits in with the overall landscape mosaic, and the long-term goals and objectives for the area or region. Keep in mind sagebrush-steppe vegetation is dynamic and management strategies must take into account multi-decade time frames. This guide provides a set of tools that will help field biologists, land managers, and private landowners conduct rapid qualitative field assessments that address the kind of site and its current state. These tools include a list of questions to be addressed and a series of photographs, keys, tables, and figures to help evaluate a site. Conducting this assessment will help prioritize sites to be treated, select the best treatment, and predict outcomes. Success of a juniper management program may be greatly enhanced if an interdisciplinary team of local managers and resource specialists, who are experienced with vegetation, fuels, soils, hydrology, wildlife, and economic and sociological aspects of the local resource, use this guide to aid their decision-making

The Sage-Grouse Habitat Mortgage: Effective Conifer Management in Space and Time

AbstractManagement of conservation-reliant species can be complicated by the need to manage ecosystem processes that operate at extended temporal horizons. One such process is the role of fire in regulating abundance of expanding conifers that disrupt sage-grouse habitat in the northern Great Basin of the United States. Removing conifers by cutting has a beneficial effect on sage-grouse habitat. However, effects may last only a few decades because conifer seedlings are not controlled and the seed bank is fully stocked. Fire treatment may be preferred because conifer control lasts longer than for mechanical treatments. The amount of conservation needed to control conifers at large temporal and spatial scales can be quantified by multiplying land area by the time needed for conifer abundance to progress to critical thresholds (i.e., “conservation volume”). The contribution of different treatments in arresting conifer succession can be calculated by dividing conservation volume by the duration of treatment effect. We estimate that fire has approximately twice the treatment life of cutting at time horizons approaching 100 yr, but, has high up-front conservation costs due to temporary loss of sagebrush. Cutting has less up-front conservation costs because sagebrush is unaffected, but it is more expensive over longer management time horizons because of decreased durability. Managing conifers within sage-grouse habitat is difficult because of the necessity to maintain the majority of the landscape in sagebrush habitat and because the threshold for negative conifer effects occurs fairly early in the successional process. The time needed for recovery of sagebrush creates limits to fire use in managing sage-grouse habitat. Utilizing a combination of fire and cutting treatments is most financially and ecologically sustainable over long time horizons involved in managing conifer-prone sage-grouse habitat

Restoring North America’s Sagebrush Steppe Ecosystem Using Seed Enhancement Technologies

Rangelands occupy over a third of global land area, and in many cases are in less than optimum condition as a result of past land use, catastrophic wildfire and other disturbance, invasive species, or climate change. Often the only means of restoring these lands involves seeding desirable species, yet there are few cost effective seeding technologies, especially for the more arid rangeland types. The inability to consistently establish desired plants from seed may indicate that the seeding technologies being used are not successful in addressing the primary sources of mortality in the progression from seed to established plant. Seed enhancement technologies allow for the physical manipulation and application of materials to the seed that can enhance germination, emergence, and/or early seedling growth. In this article we examine some of the major limiting factors impairing seedling establishment in North America’s native sagebrush steppe ecosystem, and demonstrate how seed enhancement technologies can be employed to overcome these restoration barriers. We discuss specific technologies for: (1) increasing soil water availability; (2) enhancing seedling emergence in crusting soil; (3) controlling the timing of seed germination; (4) improving plantability and emergence of small seeded species; (5) enhancing seed coverage of broadcasted seeds; and (6) improving selectivity of pre-emergent herbicide. Concepts and technologies in this paper for restoring the sagebrush steppe ecosystem may apply generally to semi-arid and arid rangelands around the globe

Saving the sagebrush sea: An ecosystem conservation plan for big sagebrush plant communities

Vegetation change and anthropogenic development are altering ecosystems and decreasing biodiversity. Successful management of ecosystems threatened by multiple stressors requires development of ecosystem conservation plans rather than single species plans. We selected the big sagebrush (Artemisia tridentata Nutt.) ecosystem to demonstrate this approach. The area occupied by the sagebrush ecosystem is declining and becoming increasingly fragmented at an alarming rate because of conifer encroachment, exotic annual grass invasion, and anthropogenic development. This is causing rangewide declines and localized extirpations of sagebrush associated fauna and flora. To develop an ecosystem conservation plan, a synthesis of existing knowledge is needed to prioritize and direct management and research. Based on the synthesis, we concluded that efforts to restore higher elevation conifer-encroached, sagebrush communities were frequently successful, while restoration of exotic annual grass-invaded, lower elevation, sagebrush communities often failed. Overcoming exotic annual grass invasion is challenging and needs additional research to improve the probability of restoration and identify areas where success would be more probable. Management of fire regimes will be paramount to conserving sagebrush communities, as infrequent fires facilitate conifer encroachment and too frequent fires promote exotic annual grasses. Anthropogenic development needs to be mitigated and reduced to protect sagebrush communities and this probably includes more conservation easements and other incentives to landowners to not develop their properties. Threats to the sustainability of sagebrush ecosystem are daunting, but a coordinated ecosystem conservation plan that focuses on applying successful practices and research to overcome limitations to conservation is most likely to yield success

Upland Bare Ground and Riparian Vegetative Cover Under Strategic Grazing Management, Continuous Stocking, and Multiyear Rest in New Mexico Mid-grass Prairie

On the Ground • We compared land cover attributes on rangeland pastures with strategically managed ranches (SGM), continuously stocked (CS), and rested pastures. • SGM pastures had less upland bare ground and more riparian vegetative cover than adjoining CS pastures, and SGM pastures had bare ground cover comparable to pastures rested from grazing for three or more years. • Differences in riparian cover between management types were greatest in years of near-average precipitation and lower in years of high precipitation or drought. • Remote sensing technologyprovided a means of quantifying range condition and comparing management effectiveness on large landscapes in a constantly changing environment

Upland Bare Ground and Riparian Vegetative Cover Under Strategic Grazing Management, Continuous Stocking, and Multiyear Rest in New Mexico Mid-grass Prairie

On the Ground • We compared land cover attributes on rangeland pastures with strategically managed ranches (SGM), continuously stocked (CS), and rested pastures. • SGM pastures had less upland bare ground and more riparian vegetative cover than adjoining CS pastures, and SGM pastures had bare ground cover comparable to pastures rested from grazing for three or more years. • Differences in riparian cover between management types were greatest in years of near-average precipitation and lower in years of high precipitation or drought. • Remote sensing technologyprovided a means of quantifying range condition and comparing management effectiveness on large landscapes in a constantly changing environment