Susan G. Stafford

Phytophage effects on primary production, nutrient turnover, and litter decomposition of young Douglas-fir in western Oregon

Abstract We tested the effect of defoliating and sap-sucking phytophages on young Douglas-fir at the H.J. Andrews Experimental Forest in western Oregon. Experimental trees were subjected to manipulated abundances of a sap-sucking insect at 0–1 insect g−1 foliage or a defoliating insect at 0 –0.06 g−1 foliage. Tree mass, throughfall, litterfall, litter decomposition, and N, K and Ca turnover were measured for each tree over a 3 year period. Herbivore abundance had no effect on calculated tree growth or nutrient content. These data suggest compensatory growth and replacement of lost nutrients. Herbivory also did not significantly affect decomposition rate for exogenous Douglas-fir needle litter. Throughfall volume, N, K and Ca content, and litterfall mass were positively related (P The results of this study support results from an eastern deciduous forest. Our study relates nutrient turnover rates to herbivore abundances, a prerequisite for modeling phytophage effects on nutrient flows.

Evolution of a multisite network information system: the LTER information management paradigm.

urban watershed, coastal estuary, eastern deciduous forest, tropical rain forest, tallgrass prairie—these are just a few of the ecosystems represented in the 24 sites of the Long-Term Ecological Research (LTER) Network (Franklin et al. 1990). By combining information from the diverse ecosystems represented in the LTER network, participants have a unique opportunity for large-scale investigations of complex phenomena like climate change, biodiversity, soil dynamics, and environmental policy. In 1996, to facilitate data exchange and synthesis from its multiple sites, LTER launched the LTER Network Information System (NIS), based on an independent site and central office organizational infrastructure. Other organizational partnerships provide examples of earlier efforts also focused on communications and data sharing: the Worm Community System, the Flora of North America Project (FNAP), and the Organization of Biological Field Stations (OBFS). The Worm Community System was developed—before Internet connectivity became available—as a collaborative software environment through which its 1400 widely dispersed researchers could share information on the genetics, behavior, and biology of the soil nematode species Caenorhabditis elegans. Insight into the complexity of a network structure was gained through attention to the design and analysis of both the system’s structure and usability (Star and Ruhleder 1996). The FNAP system, in contrast, was developed with Internet technology. The FNAP, with a goal of identifying and cataloging all plant species, uses online technology to create

Light and nutrient limitation in Pinus monticola: seedling susceptibility to Armillaria infection

Abstract Pinus monticola Dougl. seedlings were grown under eight light × nutrient treatments in a greenhouse for 5 months. One month after treatments began, seedlings were exposed to Armillaria; they were removed from their cells and inoculated by sandwiching the primary root between blocks of infected P. monticola. A small lateral root also was severed on each seedling. Seedlings grown with a complete nutrient supply and full light had significantly lower Armillaria infection rates than seedlings grown under light, nitrogen or phosphorus limitations and had significantly higher root, shoot, and total biomass and shoot: root ratios. However, root or shoot sugar or starch concentrations did not differ regardless of treatment. Seedlings given complete nutrient supply but limited light took up more Al, B, Cu, Fe, Mg, Mn, Na, P, and Zn than those given complete nutrient supply and full light; those given complete nutrient supply and full light contained significantly lower concentrations of Cu, K, Mn, Mo, and P but higher concentrations of Al, B, and Fe than seedlings given nutrient-deficient treatments. In the greenhouse, resistance of Pinus monticola to Armillaria infection depends largely on adequate light and nutrient resources; thus, creating conditions that favor tree vigor could reduce incidence of Armillaria infection, especially where light is a limiting factor.

Data, data everywhere but not a byte to read: Managing monitoring information

The problem of managing scientific information for widespread availability and use can be overwhelming. At Oregon State University, the Quantitative Sciences Group has found a workable solution. The group has developed a Forest Science Data Bank (FSDB) to house data generated by scientists and collaborating researchers in the Andrews Long-Term Ecological Research program. Today the FSDB houses some 2400 data sets from over 350 existing ecological studies and adds about 20 new studies yearly. This paper describes what we have learned in setting up the FSDB as a facility that can be used by researchers who both deposit information in and retrieve information from the FSDB.

Capacity of Second-Growth Douglas-fir and Western Hemlock Stump Anchors for Cable Logging

The use of small instead of large stumps for cable logging anchors will usually result in applied loads approaching the load capacity of the anchors more closely. The use of small stump anchors is then contingent on better means of assessing their capacity. The results of field load tests of Douglas-fir and western hemlock stump anchors are reported. Ultimate loads were modeled as power functions of DBH. In addition, the relation between load and movement relationships for the stumps are modeled using a hyperbolic function that also provides an estimate of ultimate load. Practical use of the model equations requires knowledge of failure statistics and the acceptance of a probabilistic anchor capacity. Probability is applied to the re-rigging required when an anchor fails to perform adequately and to total pull-out failure.

Recommendations for interdisciplinary study of tipping points in natural and social systems

In September 2009, the U.S. National Science Foundations (NSF) Advisory Committee for Environmental Research and Education (AC-ERE) released “Transitions and Tipping Points in Complex Environmental Systems,” a report that advocates sweeping change in the way environmental research and education are sponsored and conducted. The conviction of the committee that physical and life scientists, engineers, educators, and social scientists must work collaboratively to understand the dynamics of complex environmental systems should resonate with AGUs membership. A major theme of the AC-ERE report is that scientists need to understand environmental systems that, partly owing to human activity, may be approaching thresholds for irreversible change. This theme echoes sentiments expressed in the geosciences community, such as by Rockstrom et al. [2009], who estimate the magnitudes of thresholds for irreversible changes in nine key Earth subsystems and focus on how human activities have driven systems closer—or even past—some thresholds. The AC-ERE report argues that understanding natural systems will require integrated research among geoscientists, social scientists, ecologists, and others.

Finding leadership opportunities in an era of dual-career families

he recurring problem of a lack of diversity within national science leadership is exacerbated by the logistical problems associated with drawing women from dual-career families into leadership roles. Many of the specific issues that dual-career families face are now familiar to the BioScience readership (Foster 1993a,b, Lubchenco and Menge 1993, Wake 1993). Qualified scientists may not pursue opportunities beyond their home institutions because the problems seem insurmountable. Creative, flexible solutions are needed to enable more