The input of terrestrial invertebrates from tree canopies to a stream

SUMMARY. The input of terrestrial invertebrates from different tree canopies to a trout stream was determined for a 28-week period from April to October, 1980. Sycamore produced the greatest number of animals, followed by oak and alder. Ash was not significantly different from the controls. Coleoptera, Diptera, Homoptera and Arachnida made up the greatest number of animals caught, with Lepidoptera larvae important beneath oak. The input of biomass (g m^-2 dry wt) was also greatest beneath sycamore (35.80), followed by oak (27.76), alder (20.39), ash (11.15) and control (9.92). The input of biomass was bimodal. The significance of terrestrial invertebrates as food for salmonids is discussed.     

The Ultrastructure of Myosin-Extracted Striated Muscle Fibers

Electron microscope examination of myosin-extracted psoas muscleof the rabbit reveals a number of thin filaments, about 25 Äin diameter, bridging the gap between the ends of the actinsand the remaining myosin of the M band. Extraction of actinfrom the region of the Z disc shows similar thin filaments nearthe Z disc. Myosin-extraction of several invertebrate musclesreveals a remaining network of thin filaments in the regionof the A band. These thin filaments are probably elastic, andcould contribute to the functioning of these muscles.     

An aquatic microfossil assemblage from Cenomanian amber of France

The ‘osseous’ amber from the Cenomanian of northwestern France contains numerous microscopic inclusions, some of which are fairly well preserved and identifiable as protists. This paper describes three cyanobacteria similar to modern Plectonema. Lyngbya, and Coelosphaeriunr, fungus-like fossils of uncertain affinities (cf. ?Candida); a colorless chrysomonad similar to Monas; a desmid identical with Closterium; and naked ciliates of uncertain affinities (cf. Cyrtolophosis). All of these fossils are in a single sample of amber from Bretagnolles (Eure Département). This assemblage is comparable to modern limnetic microbial communities. It is typical of shallow freshwater environments in which productivity and respiration are both high. This interpretation fits paleoecological reconstructions drawn from the arthropod fossils from French amber. ***Chrysomonads, ciliates, Cretaceous, cyanobacteria, desmids, fungi, micropaleontology.     

Preservation of in situ reef framework in regions of low hurricane frequency: Pleistocene of Curaçao and Bonaire, southern Caribbean

Luxuriant fringing reefs along the southwestern shores of the Caribbean islands of Curaçao and Bonaire (12°N), located outside the most frequent hurricane tracks, are rarely affected by major storms. Consequently, reef growth and long-term preservation are potentially optimal and distinct from reefs experiencing greater hurricane frequency. Hurricane Lenny (November 1999) took an unusual west-to-east track, bisecting the Caribbean Basin north of these islands, but generated heavy waves (3-6  m) that severely damaged reefs along the normally leeward shores. Massive coral colonies >100 years old were toppled, but even at the most severely damaged sites, 82–85% of colonies remained in growth position. Late Pleistocene (125  ka) elevated reefs in the Lower Terrace of Curaçao record even higher proportions of corals in growth position (93%), possibly reflecting a low hurricane frequency during the Pleistocene highstand. In comparison, coeval Pleistocene reefs in regions that today experience a high hurricane frequency (Great Inagua Island and San Salvador, Bahamas) have lower proportions of corals preserved in growth position (79% and 38%, respectively). These results are consistent with the hypothesis that reefs in regions experiencing very low hurricane frequency, like the southern Caribbean, are more likely to be preserved with corals in primary growth position in comparison to regions with higher hurricane frequency.     

Phenological growth stages of North American ginseng (Panax quinquefolius)

The BBCH (Biologische Bundesanstalt, Bundessortenamt, Chemische Industrie) scale is used to describe the phonological growth stages of North American ginseng (Panax quinquefolius). Eight principal growth stages for germination and bud development, leaf development (crop canopy), root and perennating bud formation, peduncle elongation and inflorescence development, flowering and fruit set, development of fruit, ripening of fruit and senescence, and 42 secondary growth stages are described. A practical use of the scale is proposed with reference to the timing of application of agrochemicals for disease control.     

Philopatry in the alpine grasshopper, Podisma pedestris: a novel experimental and analytical method

Abstract.

• 1 Local dispersal and philopatric behaviour of the alpine grasshopper, Podisma pedestris, were studied at two sites in the Alpes Maritimes using a new mark—release—resight technique featuring marking in situ, and multiple resighting without handling. The time-consuming nature of the design was justified by the quantity and quality of the data yielded.
• 2 Philopatry is defined independently of any concept of home range as a phenomenon by which movements over longer periods are less than would be expected by extrapolation of measures over shorter periods.
• 3 By this definition, the grasshoppers are shown to exhibit philopatry. Nymphs comprise two heterogenous classes of those which move little and those which move considerable distances.
• 4 Daily dispersal estimates were obtained from movements of 1055 nymphs and adults at one site, and of 593 adults at another.
• 5 Differences are demonstrated in daily dispersal distances for age, sex and site combinations.
• 6 Some differences in microhabitat preference were observed.
• 7 The findings are compared with previous measurements of dispersal in this species, and the merits of the new technique are discussed.