Browsing by Author "MONTENEGRO, G"

Now showing 1 - 6 of 6
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    ANATOMICAL LEAF ADAPTATIONS IN VASCULAR PLANTS OF A SALT-MARSH IN THE ATACAMA DESERT (CHILE)
    (1991) POBLETE, V; CAMPOS, V; GONZALEZ, L; MONTENEGRO, G
    A community of vascular plants living in a salt marsh in the Atacama Desert (northern Chile) was studied. Environmental parameters such as high solar radiation, drought, wind and high salt concentration are the most important limiting factors. Above-ground vegetative organs of twelve species living in this environment were morphologically and microscopically analyzed in terms of adaptive features that allow them to survive under these conditions.
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    DISTRIBUTION AND ABUNDANCE OF 2 GALL-MAKERS ON THE EUPHORBIACEOUS SHRUB COLLIGUAJA-ODORIFERA
    (1992) MARTINEZ, E; MONTENEGRO, G; ELGUETA, M
    Previous studies on the interaction between the two inflorescence gall-maker insects of the euphorbiaceous shrub Colliguaja odorifera postulated a parasitoid relationship, while effects on shrub reproduction were not addressed.
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    FOOD PREFERENCES BY OCTODON-DEGUS (RODENTIA, CAVIOMORPHA) - THEIR ROLE IN THE CHILEAN MATORRAL COMPOSITION
    (1981) SIMONETTI, JA; MONTENEGRO, G
    The food preferences of O. degus were examined in laboratory tests. Degus preferred new rather than mature leaves of Chilean matorral shrubs and degus do not discriminate between new leaves (equivalents of shrub seedlings) of different shrub species. The significance of degus preferences in relation to matorral composition is discussed.
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    SECONDARY WALL INGROWTHS ON VESSEL ELEMENTS IN OMBROPHYTUM-SUBTERRANEUM (BALANOPHORACEAE)
    (1992) MAUSETH, JD; MONTENEGRO, G
    All vessel elements in the parasitic dicot Ombrophytum subterraneum (Balanophoraceae) have irregular, knobby ingrowths on their secondary walls. The ingrowths have a mean spacing of about 4-mu-m and can be longer than 6.4-mu-m, thus causing considerable occlusion of all but the widest vessel elements. The adaptive value is unknown.
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    SURFICIAL INJURIES OF SEVERAL CACTI OF SOUTH-AMERICA
    (1994) EVANS, LS; MCKENNA, C; GINOCCHIO, R; MONTENEGRO, G; KIESLING, R
    Analyses of several species of long-lived columnar cacti in Argentina and Chile show that an accumulation of epicuticular waxes is occurring on many species and that these accumulations obscure stomata. This accumulation leads to visible surficial maladies such as scaling and barking on crests and troughs of ribs similar to those that occur on saguaros, Carnegiea gigantea (giant saguaro) of North America, which results in premature death of individual saguaros. Scaling is the appearance of tan to red-orange discoloration of surfaces. Barking refers to a larger buildup of materials on the surfaces than scaling that appears dark brown to black. Equatorial facing surfaces showed more injuries on stems of Trichocereus pasacana and T. terscheckii in Argentina, and Echinopsis chilensis and E. scotsbergii in Chile, than on polar surfaces. Crest barking was as much as five times greater on equatorial-facing sides compared with polar-facing sides. Spine retention was up to three times greater on equatorial- vs polar-facing sides. The two troughs of a crest were evaluated separately. Results show that injury to one trough of a crest facing the equator was as much as twice that of the second trough being the south pole. These results show that surficial injuries were greater on equatorial than on polar surfaces, and are related to total incident irradiance on these surfaces.