A stomatal frequency record based on buried Tsuga heterophylla needles reveals significant centennial-scale atmospheric CO 2 fluctuations during the last millennium. The record includes four CO 2 minima of 260-275 ppmv (ca. A.D. 860 and A.D. 1150, and less prominently, ca. A.D. 1600 and 1800). Alternating CO 2 maxima of 300-320 ppmv are present at A.D. 1000, A.D. 1300, and ca. A.D. 1700. These CO 2 fluctuations parallel global terrestrial air temperature changes, as well as oceanic surface temperature fluctuations in the North Atlantic. The results obtained in this study corroborate the notion of a continuous coupling of the preindustrial atmospheric CO 2 regime and climate.
Between 9 and 22 January 1999, radio-tracking revealed that nine Sturnira lzlium (seven females, one lactating, and two males) used hollow trees (N = 5), vine tangles ( N = 2), or the bases of palm fronds (N = 1) as day roosts near Lamanai in Belize over 43 roost days. The bats roosted in hollows of four tree species, and the roost entrances ranged from 2.0 to 7.9 m above the ground. Radio-tagged individuals returned to the same roosts day after day, with the exception of a subadult female that used at least three day roosts over the course of the study. In their day roosts, S. lilium were inconspicuous, difficult to flush, and easily overlooked. Radio-tagged bats usually roosted alone and emerged significantly later than bats without radio tags.
Between 9 and 22 January 1999, radio-tracking revealed that nine Sturnira lzlium (seven females, one lactating, and two males) used hollow trees (N = 5), vine tangles ( N = 2), or the bases of palm fronds (N = 1) as day roosts near Lamanai in Belize over 43 roost days. The bats roosted in hollows of four tree species, and the roost entrances ranged from 2.0 to 7.9 m above the ground. Radio-tagged individuals returned to the same roosts day after day, with the exception of a subadult female that used at least three day roosts over the course of the study. In their day roosts, S.lilium were inconspicuous, difficult to flush, and easily overlooked. Radio-tagged bats usually roosted alone and emerged significantly later than bats without radio tags.
Petunia × hybrida Vilm. cvs. `Purple Wave', `Celebrity Burgundy', `Fantasy Pink Morn', and `Dreams Red' were treated with temperature and photoperiod treatments for different lengths of time at different stages of development during the first 6 weeks after germination. Plants were grown with ambient light (≈8–9 hr) at 16°C before and after treatments. Flowering was earliest and leaf number below the first flower was lowest when plants were grown under daylight plus 100 μmol·m–2·s–1 continuous light (high-pressure sodium lamps). Flowering did not occur when plants were grown under short-day treatment (8-hr daylight). Plants grown with night interruption lighting from 2200–0200 HR (2 μmol·m–2·s–1 from incandescent lamps) flowered earlier, and with a reduced leaf number compared to plants grown with daylight + a 3-hr day extension from 1700–2000 HR (100 μmol·m–2·s–1 using high-pressure sodium lamps). Plant height and internode elongation were greatest and least in night interruption and continuous light treatments, respectively. `Fantasy Pink Morn' and `Purple Wave' were the earliest and latest cultivars to flower, respectively. Flowering was hastened as temperature increased from 12 to 20°C, but not as temperature was further increased from 20 to 24°C. Branching increased as temperature decreased from 24 to 12°C. Implications of data with respect to classification of petunia flower induction and pre-fi nishing seedlings are discussed.
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