Applications of wetting-agent solutions produce mortality in birds. The exact cause of death is undetermined, but it is believed that destruction of the insulating qualities of the plumage permits ambient cold temperatures and evaporation to lower the body temperature to a lethal level. The original concept of using these materials as bird-control tools was developed in 1958 at the Patuxent Wildlife Research Center, Bureau of Sport Fisheries and Wildlife, Laurel, MD. Early field trials by personnel of the Division of Wildlife Services and the Denver Wildlife Research Center indicated that ground-application techniques had promise but limitations of the equipment precluded successful large-scale roost treatments. In 1966, Patuxent Center personnel began using tanker-type aircraft to evaluate high-volume aerial applications of wetting agents. The success of these tests led to the use of small aircraft to make low-volume, high-concentration aerial applications just prior to expected rainfall. Recent trials of the low-volume method show that, with some limitations, it is effective, inexpensive, and safe to the environment. Current research emphasizes the screening of new candidate materials for efficacy, biodegradability, and toxicity to plants and non-target animals, as well as basic investigations of the avian physiological mechanisms involved. Field trials to develop more effective application techniques will continue.

The effectiveness of eyespot balloons in discouraging boat-tailed grackle (Quiscalus major) use of a simulated orange grove was investigated in a series of 4-day trials. The mean distance to the trees of 6-bird experimental flocks was the same with a plain white balloon present as with no balloon. A white balloon with red and black eyespots kept birds at a greater distance from the trees throughout the trial. The presence of a black balloon with orange and yellow eyespots did not repel the birds from the grove. Observations of birds using the area within 1 m of the trees revealed no effect due to the eyespot balloons nor was the number of oranges pecked reduced in the presence of the eyespot balloons. These results were primarily due to a single bird that consistently ignored the white eyespot balloon during the 4-day trial, entered the grove, and avidly pecked the fruit. In combination with other crop protection devices, eyespot balloons may prove effective in deterring bird use of citrus trees.

Rooting depth affects soil profiles of water uptake and carbon inputs. Here we explore the importance of deep roots in a mature tropical forest of eastern Amazonia, where a throughfall exclusion experiment was conducted to test the resilience of the forest to experimentally induced drought. We hypothesized that soil water depletion occurred below the depth previously measured by sensors in 11-m-deep soil pits and that only a small root biomass is necessary to affect water uptake and the isotopic signature of soil CO2. A noninvasive electrical profiling method demonstrated greater depletion of soil water in the 11-18 m depth increment in the exclusion plot compared with the control plot by the end of the 3rd year of the experiment. A fine root biomass of only 0.1 g/cm3 measured at 3-6 m was sufficient for soil water drawdown and for imparting an isotopic signature of modern soil 14CO2 in both plots. A soil 13CO2 profile indicated drought stress in the exclusion plot. Fine root inputs of organic C to deep soils are small with respect to the carbon dynamics of the forest, but the deep rooting habit clearly affects the ecosystem water balance and profiles of soil CO2. © 2011 by the Society of American Foresters.

DEFORESTATION and logging transform more forest in eastern and southern Amazonia than in any other region of the world1-3. This forest alteration affects regional hydrology4-11 and the global carbon cycle12-14, but current analyses of these effects neglect an important deep-soil link between the water and carbon cycles. Using rainfall data, satellite imagery and field studies, we estimate here that half of the closed forests of Brazilian Amazonia depend on deep root systems to maintain green canopies during the dry season. Evergreen forests in northeastern Pará state maintain evapotranspiration during five-month dry periods by absorbing water from the soil to depths of more than 8m. In contrast, although the degraded pastures of this region also contain deep-rooted woody plants, most pasture plants substantially reduce their leaf canopy in response to seasonal drought, thus reducing dry-season evapotranspiration and increasing potential subsurface runoff relative to the forests they replace. Deep roots that extract water also provide carbon to the soil. The forest soil below 1 m depth contains more carbon than does above-ground biomass, and as much as 15% of this deep-soil carbon turns over on annual or decadal timescales. Thus, forest alteration that affects depth distributions of carbon inputs from roots may also affect net carbon storage in the soil. © 2002 Nature Publishing Group.

Chlamydomonas reinhardtii is a unicellular green alga whose lineage diverged from land plants over 1 billion years ago. It is a model system for studying chloroplast-based photosynthesis, as well as the structure, assembly, and function of eukaryotic flagella (cilia), which were inherited from the common ancestor of plants and animals, but lost in land plants. We sequenced the 120-megabase nuclear genome of Chlamydomonas and performed comparative phylogenomic analyses, identifying genes encoding uncharacterized proteins that are likely associated with the function and biogenesis of chloroplasts or eukaryotic flagella. Analyses of the Chlamydomonas genome advance our understanding of the ancestral eukaryotic cell, reveal previously unknown genes associated with photosynthetic and flagellar functions, and establish links between ciliopathy and the composition and function of flagella.