Data from the Women's Health Initiative were used to quantify the relationship between the loss of trees to an invasive forest pest—the emerald ash borer—and cardiovascular disease. We estimated semi- parametric Cox proportional hazards model of time to cardiovascular disease, adjusting for confounders. We defined the incidence of cardiovascular disease as acute myocardial infarction requiring overnight hospitalization, silent MI determined from serial electrocardiograms, ischemic or hemorrhagic stroke,or death from coronary heart disease. Women living in a county infested with emerald ash borer had an increased risk of cardiovascular disease(HR=1.25, 95% CI: 1.20–1.31).
Aim We evaluated whether the performance of individuals and populations of the invasive plant Verbascum thapsus differs between its native and non-native ranges, across climate gradients, and in response to its position in a global- scaled niche model.
Location India (Kashmir) and Switzerland (native range) and Australia and USA (Hawaii, Montana and Oregon) (non-native range).
Methods We measured population characteristics (density of flowering indi- viduals, population size), plant traits (plant height, number of flowering branches) and seed germination for 50 populations of V. thapsus growing along elevational gradients in six mountain regions around the world (two in the native range, and four in the non-native range). We fitted linear regression models to determine the relationship of plant and population level perfor- mance variables to range, region, climate and probability of occurrence from a global niche model.
Results Plant height, number of flowering branches and population density of V. thapsus did not differ consistently between the native and non-native ranges, but the area covered by populations in the non-native range was on average two orders of magnitude larger than the area of native populations. Within and among regions, individual plant performance traits responded variably to precipitation and mean annual temperature, depending on the climatic range of the observed populations; however, performance was greater for populations that had a greater modelled probability of occurrence. Seed germination under controlled conditions was highest between 20 and 35 °C and consistent across populations, although germination at low temperatures was substantially higher for native populations from Kashmir.
Main conclusions The introduction of V. thapsus to its non-native range is not associated with consistent increases in plant performance. Instead, plant performance is more strongly influenced by position within the climate niche of the species, position along environmental gradients, and climatic or other differences among regions. We demonstrate that individual-level and popula- tion-level performance traits can yield different predictors of plant perfor- mance. Therefore, future studies comparing plant performance in native and non-native ranges should include both plant and population characteristics and should also sample the target species from multiple regions in both ranges and along environmental gradients that comprehensively represent the niche of the species
Many modern environmental problems span vastly different spatial scales, from the management of local ecosystems to understanding globally interconnected processes, and addressing them through international policy. MIREN tackles one such “glocal” (global/local) environmental problem – plant invasions in mountains – through a transdisciplinary, multi-scale learning process at the science-policy interface. The approach led to a new framing of invasions in mountains, and promoted innovation by engaging scientists and practitioners.
Herbicides are primarily used for protecting agricultural crops from weeds and controlling vegetation competition in newly planted forest stands. Yet for over 40 years, they have also proven useful in controlling invasive plant species in natural areas. Nonnative invasive plant species, if not controlled, can displace native species and disrupt an ecosystem by changing soil chemical and biological properties. However, before an herbicide may be applied in a U.S. national forest, toxicological and ecological assessments and field testing are required to ensure it won’t negatively affect the landscape or people.
In the Gifford Pinchot National Forest, scientists with the U.S. Forest Service Pacific Northwest Research Station established experimental plots to test effects of aminopyralid (a plant growth-regulating herbicide) on both the nonnative and native meadow plant species. When applying less than the manufacturer’s maximum labeled rate, researchers found the herbicide reduced the cover of Canada thistle and other nonnatives without strongly affecting native species.
Aminopyralid, along with aminocyclopyrachlor and clopyralid (also plant growth-regulating herbicides), were also tested in a growth chamber trial for their effectiveness in controlling the germination of Scotch broom, a large invasive shrub that often reduces survival of young Douglas-fir. Spraying the soil with each type of herbicide controlled up to 90 percent of the germinating Scotch broom seedlings.
This chapter sets the context for the following sociocultural sections of the synthesis by providing information on the broader social, cultural, and economic patterns in the Sierra Nevada and southern Cascade Range. Demographic influences surrounding population change, including those accounted for through amenity migration, are examined. Social and cultural concerns surrounding place meanings and place attachments are reviewed next, including potential influences on responses to natural resource management. Managing for resilience includes effectively applying a “triple bottom line approach,” presented in this chapter through a discussion of recreation and tourism, one of the ecosystem services of importance in the assessment region.
Four rates of aminopyralid (30, 60, 90, and 120 g ae ha-1 [0.4, 0.9, 1.3, and 1.8 oz ae acre-1]) were compared for their ability to reduce abundance of nonnative dicot species and favor native species in an invaded Cascade Mountain meadow near Trout Lake, WA. Treatments were applied in two replicated studies (June 2009 and 2010), and foliar cover and species richness were monitored for two years. First-year control of nonnative dicots from application of 30 g ae ha-1 of aminopyralid (69%) was greater than that of native dicots (29%); whereas, significant control of both species groups occurred at the higher rates. By the second year after treatment, absolute differences in cover between treated and non-treated plots averaged 217% and 221% for native and nonnative dicots, respectively, and +1% and +27% for native and nonnative monocots, respectively. First-year control of Canada thistle and oxeye daisy was greater after treatment in 2009 (88% and 90%, respectively) than after treatment in 2010 (56% and 55%, respectively), probably because lower spring temperatures in 2010 limited vegetation development and plant susceptibility to aminopyralid. Cover of Kentucky bluegrass and sheep fescue averaged 20% and 6% greater, respectively, in treated plots than in non-treated plots. Application of 30 g ae ha-1 of aminopyralid had no detectable effect on second-year richness of native and nonnative species relative to non-treated plots; however, higher rates caused 24% to 43% reductions in richness of each species group. Research results suggest that application of aminopyralid at 30 g ae ha-1 has the potential to reduce abundance of nonnative dicot species in similar meadow communities of the Pacific Northwest with little or no negative impacts to abundance and richness of native species. As a potential strategy to limit the subsequent spread of Kentucky bluegrass, a grass herbicide, such as fluazifop or sethoxydim, could be added to the treatment.
Previous chapters of this synthesis rely on multiple ecological disciplines to frame core aspects of a sustainable, resilient ecosystem. Approaching forest management in the Sierra Nevada and southern Cascade Range in a manner that promotes socioecological resilience and sustains important forest values requires consideration of not only the ecological, but also the social, economic, cultural, and institutional components of the ecosystem, using a systems approach (Higgins and Duane 2008). The term "socioecological system" has been widely used in scientific literature on resilience. Key ideas underpinning the concept of integrated socioecological systems are: interactions between biophysical and social factors; linkages across spatial, temporal, and organizational scales; regulation of the flow and use of critical resources that are natural, socioeconomic, and cultural; and continuous adaptation (Redman et al. 2004).
Disease processes are dynamic, involving a suite of gene expression changes in both the host and the pathogen, all within a single tissue. As such, they lend themselves well to transcriptomic analysis. Here we focus on a generalist invasive pathogen (Phytophthora ramorum) and its most susceptible California Floristic Province native host, tanoak (Notholithocarpus densiflorus (Hook. & Arn.) Manos, Cannon & S.H. Oh). The advent of new sequencing technologies has made the study of non-model systems possible at a scale never before possible. We argue that this non-model system is ideal for studying the interactions between host and pathogen using massively parallel mRNA sequencing, in part because the P. ramorum genome has been fully sequenced.
We present early data in a project developed to elucidate the molecular genetic interactions between these two species. We used the Illumina Genetic Analyzer system to sequence all mRNA present in a single tanoak genotype after inoculation with P. ramorum, and from a non-inoculated control. We separated sequences from the dataset that originated from the pathogen, or from highly conserved regions, by aligning the reads to the P. ramorum genome; this first set includes the genes expressed in vivo by the pathogen. The remaining sequences were used to generate a de novo reference transcriptome for tanoak, and then to subsequently pinpoint gene regions of interest with increased or decreased expression after infection. Each of the three outcomes—the set of expressed P. ramorum gene regions, the tanoak gene regions showing changes in expression, and the tanoak transcriptome reference itself—are an important step in understanding the interactions of forest pathogens and their hosts at the molecular level.
Development owing to population increases over the last 30 years has greatly affected forested lands in the United States. To assess and compare increases in development, we counted changes in the number of structures on a systematic grid of photointerpreted points around public forest land in Washington and Oregon. Areas bordering public forest land are showing substantial increases in development, with the number of structures on private lands near almost all types of public forest more than doubling between the 1970s and 2000s. Lands bordering Washington’s Department of Natural Resources lands have more than twice as many new structures along their edges compared to other public owners. In Oregon, the greatest amount of development occurred along the edges of Bureau of Land Management forests. The greatest increases in structure density along the borders of public forests occurred in Pierce, King, Snohomish, and Clark Counties in Washington, and Deschutes County in Oregon. The continuing development pressure along the edges of public forests in Washington and Oregon has numerous consequences, including increased road density with more human-caused ignition of wildfire, higher probability for invasive species, greater demand for local recreation, higher fire suppression costs, and increased complexity for managers trying to reduce wildfire hazard through fuel treatments.
Well-functioning food webs are fundamental for sustaining rivers as ecosystems and maintaining associated aquatic and terrestrial communities. The current emphasis on restoring habitat structure-without explicitly considering food webs-has been less successful than hoped in terms of enhancing the status of targeted species and often overlooks important constraints on ecologically effective restoration. We identify three priority food web-related issues that potentially impede successful river restoration: uncertainty about habitat carrying capacity, proliferation of chemicals and contaminants, and emergence of hybrid food webs containing a mixture of native and invasive species. Additionally, there is the need to place these food web considerations in a broad temporal and spatial framework by understanding the consequences of altered nutrient, organic matter (energy), water, and thermal sources and flows, reconnecting critical habitats and their food webs, and restoring for changing environments. As an illustration, we discuss how the Columbia River Basin, site of one of the largest aquatic/riparian restoration programs in the United States, would benefit from implementing a food web perspective. A food web perspective for the Columbia River would complement ongoing approaches and enhance the ability to meet the vision and legal obligations of the US Endangered Species Act, the Northwest Power Act (Fish and Wildlife Program), and federal treaties with Northwest Indian Tribes while meeting fundamental needs for improved river management.