Persistent reduced ecosystem respiration after insect disturbance in high elevation forests

Amid a worldwide increase in tree mortality, mountain pine beetles (Dendroctonus ponderosae Hopkins) have led to the death of billions of trees from Mexico to Alaska since 2000. This is predicted to have important carbon, water and energy balance feedbacks on the Earth system. Counter to current projections, we show that on a decadal scale, tree mortality causes no increase in ecosystem respiration from scales of several square metres up to an 84 km2 valley. Rather, we found comparable declines in both gross primary productivity and respiration suggesting little change in net flux, with a transitory recovery of respiration 6–7 years after mortality associated with increased incorporation of leaf litter C into soil organic matter, followed by further decline in years 8–10. The mechanism of the impact of tree mortality caused by these biotic disturbances is consistent with reduced input rather than increased output of carbon

Meeting the home-care needs of disabled older persons living in the community: does integrated services delivery make a difference?

<p>Abstract</p> <p>Background</p> <p>The PRISMA Model is an innovative coordination-type integrated-service-delivery (ISD) network designed to manage and better match resources to the complex and evolving needs of elders. The goal of this study was to examine the impact of this ISD network on unmet needs among disabled older persons living in the community.</p> <p>Methods</p> <p>Using data from the PRISMA study, we compared unmet needs of elders living in the community in areas with or without an ISD network. Disabilities and unmet needs were assessed with the Functional Autonomy Measurement System (SMAF). We used growth-curve analysis to examine changes in unmet needs over time and the variables associated with initial status and change. Sociodemographic characteristics, level of disability, self-perceived health status, cognitive functioning, level of empowerment, and the hours of care received were investigated as covariates. Lastly, we report the prevalence of needs and unmet needs for 29 activities in both areas at the end of the study.</p> <p>Results</p> <p>On average, participants were 83 years old; 62% were women. They had a moderate level of disability and mild cognitive problems. On average, they received 2.07 hours/day (SD = 1.08) of disability-related care, mostly provided by family. The findings from growth-curve analysis suggest that elders living in the area where ISD was implemented and those with higher levels of disability experience better fulfillment of their needs over time. Besides the area, being a woman, living alone, having a higher level of disability, more cognitive impairments, and a lower level of empowerment were linked to initial unmet needs (r²= 0.25; p < 0.001). At the end of the study, 35% (95% CI: 31% to 40%) of elders with needs living in the ISD area had at least one unmet need, compared to 67% (95% CI: 62% to 71%) in the other area. In general, unmet needs were highest for bathing, grooming, urinary incontinence, walking outside, seeing, hearing, preparing meals, and taking medications.</p> <p>Conclusions</p> <p>In spite of more than 30 years of home-care services in the province of Quebec, disabled older adults living in the community still have unmet needs. ISD networks such as the PRISMA Model, however, appear to offer an effective response to the long-term-care needs of the elderly.</p

Short-term geriatric assessment units: 30 years later

<p>Abstract</p> <p>Background</p> <p>The increasing number of hospitalized elderly persons has greatly challenged decision makers to reorganize services so as to meet the needs of this clientele. Established progressively over the last 30 years, the short-term Geriatric Assessment Unit (GAU) is a specialized care program, now implemented in all the general hospital centres in Quebec. Within the scope of a broader reflection upon the appropriate care delivery for elderly patients in our demographic context, there is a need to revisit the role of GAU within the hospital and the continuum of care. The objective of this project is to describe the range of activities offered by Quebec GAU and the resources available to them.</p> <p>Methods</p> <p>In 2004, 64 managers of 71 GAU answered a mail questionnaire which included 119 items covering their unit's operation and resources in 2002-2003. The clinical and administrative characteristics of the clientele admitted during this period were obtained from the provincial database Med-Echo. The results were presented according to the geographical location of GAU, their size, their university academic affiliation, the composition of their medical staff, and their clinical care profile.</p> <p>Results</p> <p>Overall, GAU programs admitted 9% of all patients aged 65 years and older in the surveyed year. GAU patients presented one or more geriatric syndromes, including dementia. Based on their clientele, three distinct clinical care profiles of GAU were identified. Only 19% of GAU were focused on geriatric assessment and acute care management; 23% mainly offered rehabilitation care, and the others offered a mix of both types. Thus, there was a significant heterogeneity in GAU's operation.</p> <p>Conclusions</p> <p>The GAU is at the cutting edge of geriatric services in hospital centres. Given the scarcity of these resources, it would be appropriate to better target the clientele that may benefit from them. Standardizing and promoting GAU's primary role in acute care must be reinforced. In order to meet the needs of the frail elderly not admitted in GAU, alternative care models centered on prevention of functional decline must be applied throughout all hospital wards.</p

Changes in Soil Biogeochemistry Following Disturbance by Girdling and Mountain Pine Beetles in Subalpine Forests

A recent unprecedented epidemic of beetle-induced tree mortality has occurred in the lodgepole pine forests of Western North America. Here, we present the results of studies in two subalpine forests in the Rocky Mountains, one that experienced natural pine beetle disturbance and one that experienced simulated disturbance imposed through bole girdling. We assessed changes to soil microclimate and biogeochemical pools in plots representing different post-disturbance chronosequences. High plot tree mortality, whether due to girdling or beetle infestation, caused similar alterations in soil nutrient pools. During the first 4 years after disturbance, sharp declines were observed in the soil dissolved organic carbon (DOC) concentration (45–51 %), microbial biomass carbon concentration (33–39 %), dissolved organic nitrogen (DON) concentration (31–42 %), and inorganic phosphorus (PO4 3−) concentration (53–55 %). Five to six years after disturbance, concentrations of DOC, DON, and PO4 3− recovered to 71–140 % of those measured in undisturbed plots. Recovery was coincident with observed increases in litter depth and the sublitter, soil O-horizon. During the 4 years following disturbance, soil ammonium, but not nitrate, increased to 2–3 times the levels measured in undisturbed plots. Microbial biomass N increased in plots where increased ammonium was available. Our results show that previously observed declines in soil respiration following beetle-induced disturbance are accompanied by losses in key soil nutrients. Recovery of the soil nutrient pool occurs only after several years following disturbance, and is correlated with progressive mineralization of dead tree litter

Leaf isoprene emission rate as a function of atmospheric CO2 concentration

There is considerable interest in modeling isoprene emissions from terrestrial vegetation, because these emissions exert a principal control over the oxidative capacity of the troposphere

High Productivity in Hybrid-poplar Plantations Without Isoprene Emission to the Atmosphere

Hybrid-poplar tree plantations provide a source for biofuel and biomass, but they also increase forest isoprene emissions. The consequences of increased isoprene emissions include higher rates of tropospheric ozone production, increases in the lifetime of methane, and increases in atmospheric aerosol production, all of which affect the global energy budget and/or lead to the degradation of air quality. Using RNA interference (RNAi) to suppress isoprene emission, we show that this trait, which is thought to be required for the tolerance of abiotic stress, is not required for high rates of photosynthesis and woody biomass production in the agroforest plantation environment, even in areas with high levels of climatic stress. Biomass production over 4 y in plantations in Arizona and Oregon was similar among genetic lines that emitted or did not emit significant amounts of isoprene. Lines that had substantially reduced isoprene emission rates also showed decreases in flavonol pigments, which reduce oxidative damage during extremes of abiotic stress, a pattern that would be expected to amplify metabolic dysfunction in the absence of isoprene production in stress-prone climate regimes. However, compensatory increases in the expression of other proteomic components, especially those associated with the production of protective compounds, such as carotenoids and terpenoids, and the fact that most biomass is produced prior to the hottest and driest part of the growing season explain the observed pattern of high biomass production with low isoprene emission. Our results show that it is possible to reduce the deleterious influences of isoprene on the atmosphere, while sustaining woody biomass production in temperate agroforest plantations

BEHAVIOR-ANALYTIC RESEARCH ON DEMENTIA IN OLDER ADULTS

It is estimated that 1 in 10 adults aged 65 years and older have been diagnosed with dementia, which is associated with numerous behavioral excesses and deficits. Despite the publication of a special section of the Journal of Applied Behavior Analysis (JABA) on behavioral gerontology (Iwata, 1986), there continues to be a paucity of behavior-analytic research with this population. This review compares the research published before and after the behavioral gerontology special section and evaluates the most recently published aging articles in JABA