GLORIA

GEOMAR Library Ocean Research Information Access

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Online Resource
    Online Resource
    Oxford :Oxford University Press, Incorporated,
    Keywords: Mountain ecology -- Colorado -- Niwot Ridge. ; Environmental sciences. ; Electronic books.
    Type of Medium: Online Resource
    Pages: 1 online resource (352 pages)
    Edition: 1st ed.
    ISBN: 9780195344295
    Series Statement: Long-Term Ecological Research Network Series
    DDC: 577.5/38/0978863
    Language: English
    Note: Intro -- Contents -- Contributors -- Foreword -- 1 Introduction: Historical Perspective and Significance of Alpine Ecosystem Studies -- I: Physical Environment -- 2 Climate -- 3 Atmospheric Chemistry and Deposition -- 4 Geomorphic Systems of Green Lakes Valley -- 5 Hydrology and Hydrochemistry -- II: Ecosystem Structure -- 6 The Vegetation: Hierarchical Species-Environment Relationships -- 7 Vertebrates -- 8 Soils -- III: Ecosystem Function -- 9 Primary Production -- 10 Plant Nutrient Relations -- 11 Controls on Decomposition Processes in Alpine Tundra -- 12 Nitrogen Cycling -- 13 Soil-Atmosphere Gas Exchange -- 14 Plant-Herbivore Interactions -- IV: Past and Future -- 15 Paleoecology and Late Quaternary Environments of the Colorado Rockies -- 16 Environmental Change and Future Directions in Alpine Research -- Index -- A -- B -- C -- D -- E -- F -- G -- H -- I -- J -- K -- L -- M -- N -- O -- P -- R -- S -- T -- V -- W.
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Physiologia plantarum 65 (1985), S. 0 
    ISSN: 1399-3054
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: An important physiological feature of chaparral shrubs is the development of low water potentials during periods of drought characteristic of southern Californian summers. Changes in tissue elasticity may be an important characteristic allowing these low water potentials to be reached and maintained without the development of detrimental water deficits. To examine this possibility, seasonal changes in tissue elasticity were measured in 3 species of chaparral shrubs, Arctostaphylos glandulosa Eastw., Quercus dumosa Nutt. and Ceanothus greggii Gray., by the pressure-volume method. Tissue elasticity was characterized using graphs of the modulus of elasticity plotted as a function of turgor pressure, and maximum values of the elastic modulus. The moduli of elasticity of the shrubs increased following leaf emergence in the spring, were highest during periods of low soil water potential, and tended to decrease following the summer-fall drought period. Increases in tissue elasticity facilitate water uptake from drying soils, but result in greater turgor loss during tissue dehydration.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Soils contain the largest near-surface reservoir of terrestrial carbon and so knowledge of the factors controlling soil carbon storage and turnover is essential for understanding the changing global carbon cycle. The influence of climate on decomposition of soil carbon has been well documented, ...
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-1939
    Keywords: Key words Respiration ; Leaf life-span ; Specific leaf area ; Nitrogen ; Functional groups
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Based on prior evidence of coordinated multiple leaf trait scaling, we hypothesized that variation among species in leaf dark respiration rate (R d) should scale with variation in traits such as leaf nitrogen (N), leaf life-span, specific leaf area (SLA), and net photosynthetic capacity (A max). However, it is not known whether such scaling, if it exists, is similar among disparate biomes and plant functional types. We tested this idea by examining the interspecific relationships between R d measured at a standard temperature and leaf life-span, N, SLA and A max for 69 species from four functional groups (forbs, broad-leafed trees and shrubs, and needle-leafed conifers) in six biomes traversing the Americas: alpine tundra/subalpine forest, Colorado; cold temperate forest/grassland, Wisconsin; cool temperate forest, North Carolina; desert/shrubland, New Mexico; subtropical forest, South Carolina; and tropical rain forest, Amazonas, Venezuela. Area-based R d was positively related to area-based leaf N within functional groups and for all species pooled, but not when comparing among species within any site. At all sites, mass-based R d (R d-mass) decreased sharply with increasing leaf life-span and was positively related to SLA and mass-based A max and leaf N (leaf N mass). These intra-biome relationships were similar in shape and slope among sites, where in each case we compared species belonging to different plant functional groups. Significant R d-mass−N mass relationships were observed in all functional groups (pooled across sites), but the relationships differed, with higher R d at any given leaf N in functional groups (such as forbs) with higher SLA and shorter leaf life-span. Regardless of biome or functional group, R d-mass was well predicted by all combinations of leaf life-span, N mass and/or SLA (r 2≥ 0.79, P 〈 0.0001). At any given SLA, R d-mass rises with increasing N mass and/or decreasing leaf life-span; and at any level of N mass, R d-mass rises with increasing SLA and/or decreasing leaf life-span. The relationships between R d and leaf traits observed in this study support the idea of a global set of predictable interrelationships between key leaf morphological, chemical and metabolic traits.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-1939
    Keywords: Key words Alpine tundra ; Biotic interactions ; Community structure ; Nitrogen ; Trifolium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Alpine Trifolium species have high rates of symbiotic N2-fixation which may influence the abundance and growth of plant species growing near them. The potential for facilitative effects on plant abundance and growth in dry meadow alpine tundra of Niwot Ridge, Colo., characterized by low resource availability, was investigated by measuring soil N, aboveground biomass production, and plant species composition in patches of Trifolium dasyphyllum and surrounding tundra. Extractable inorganic N was more than twofold greater and extractable P was 27% lower in Trifolium patches than in surrounding tundra. Aboveground production was twofold greater in Trifolium patches than in surrounding tundra. However, the difference was largely due to the production of T. dasyphyllum relative to the non-Trifolium component of biomass, which was not different between the Trifolium patches and surrounding tundra. In the Trifolium patches, the proportion of graminoid biomass was lower while the proportion of forb biomass was higher relative to surrounding tundra. Although the abundance of some species was positively associated with the presence of Trifolium, other species were less abundant, possibly due to increased competition for P and differential abilities of alpine species to respond to increased N availability. Trifolium may exert both facilitative and inhibitive effects on dry meadow alpine species and, in the process, substantially influence the spatial heterogeneity in community structure and primary production.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1432-1939
    Keywords: Alpine ecosystem ; δ15N ; Nitrogen cycling ; Symbiotic N2-fixation ; Trifolium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Annual inputs of symbiotic N2-fixation associated with 3 species of alpine Trifolium were estimated in four alpine communities differing in resource supplies. We hypothesized that fixation rates would vary according to the degree of N, P, and water limitation of production, with the higher rates of fixation in N limited communities (dry meadow, moist meadow) and lower rates in P and water limited communities (wet meadow, fellfield). To estimate N2-fixation rates, natural abundance of N isotopes (δ15N) were measured in field collected Trifolium and reference plants and in Trifolium plants grown in N-free medium in a growth chamber. All three Trifolium species relied on a large proportion of atmospherically-fixed N2 to meet their N requirements, ranging from 70 to 100%. There were no apparent differences in the proportion of plant N derived from fixation among the communities, but differences in the contribution of the Trifolium species to community cover resulted in a wide range of annual N inputs from fixation, from 127 mg m−2 year−1 in wet meadows to 810 mg m−2 year−1 in fellfields. Annual spatially integrated input of symbiotic N2-fixation to Niwot Ridge, Colorado was estimated at 490 mg m−2 year−1 (5 kg ha−1 year−1), which is relatively high in the context of estimates of net N mineralization and N deposition.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1432-1939
    Keywords: Alpine tundra ; Nitrogen ; Physiological response to resource additions ; Plant growth form Primary production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Physiological and growth measurements were made on forbs and graminoids following additions of water and N+water in a graminoid-dominated dry meadow and a forb-dominated moist meadow, to determine if the community-level response was related to differential responses between the growth forms. Graminoids had higher photosynthetic rates and lower transpiration rates and foliar N concentrations than forbs, and consequently maintained higher photosynthetic N- and water-use efficiencies. Photosynthetic rates, stomatal conductance, and transpiration rates increased significantly only in response to N fertilization and only in moist meadow species. The increase in photosynthetic rates was unrelated to variation in foliar N concentration, but instead correlated with variation in stomatal conductance. Growth based N-use efficiency was higher in moist meadow graminoids than in moist meadow forbs, but did not differ between the growth forms in the dry meadow. The moist meadow community had higher biomass and N standing crops, but the relative increase in these factors in response to N fertilization was greater in the dry meadow. Graminoids had a greater relative increase in biomass and N accumulation than forbs following N fertilization, but moist meadow graminoids exhibited a greater response than dry meadow graminoids. The difference in the growth response between the dry meadow and moist meadow graminoids to N fertilization was correlated with more conservative leaf gas exchange responses in dry meadow species, presumably related to a higher frequency of soil water deficits in this community. Community-level response to the resource additions was therefore mediated by the plant growth form response, corresponding with differences between the growth forms in physiological factors related to resource acquisition and use.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1432-1939
    Keywords: Ion uptake ; Nonhalophyte ; Osmotic adjustment ; Photosynthetic inhibition ; Salt tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary To examine the importance of Na+ and Cl- to osmotic adjustment in a salt-tolerant ecotype of the C4 nonhalophyte Andropogon glomeratus, plants were watered with sorbitol, a neutral osmoticum, and synthetic seawater, for five days. Gas exchange measurements were made during the course of the watering treatment and during a recovery period following treatment. Leaf osmotic adjustment occurred only in plants watered with seawater, and was associated with an increase in Na+ and Cl- concentrations. Estimates of the molar concentrations indicated these ions could account for 95% of the leaf osmotic adjustment. Net photosynthetic CO2 uptake was less effected during the watering treatment, and photosynthetic recovery was greater following the treatment in plants watered with seawater. Photosynthetic inhibition was related primarily to metabolic factors, including a decrease in carboxylation efficiency. A model is presented for a mechanism promoting tolerance to transient seawater inundation in A. glomeratus.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1432-1939
    Keywords: Ahdropogon glomeratus ; Genetic differentiation ; Growth response ; Salinity ; Stress tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This research was undertaken to investigate differences in salt tolerance under conditions in which salinity is increased gradually and maintained for long periods or increased rapidly and maintained for shorter periods. The responses of populations of a C4 nonhalophytic grass, Andropogon glomeratus, to long- and short-term salinity were measured under controlled environment conditions. Additionally, plants from a salt marsh population and an inland population were transplanted into a salt marsh and their survival compared. The relative growth reductions in the salt marsh and the inland populations under long-term salinity were similar. Survival of seedlings of 4 populations inundated with full-strength seawater over a relatively short period indicated differential capacities to tolerate soil salinities imposed in a manner similar to tidal inundation in a salt marsh. The greater survival of plants from the marsh population transplanted into the salt marsh further indicated genetic differentiation between the populations. These results indicate that genetic differentiation to salt tolerance in A. glomeratus is better reflected by survival after shortterm salinity events, rather than growth inhibition due to long-term salinity imposed gradually.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1432-1939
    Keywords: Andropogon glomeratus ; A-Ci curves ; Osmotic adjustment ; Photosynthesis ; Salinity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Andropogon glomeratus is a C4 nonhalophytic grass which exhibits population differentiation for tolerance to short-term salinity exposure. To investigate possible physiological mechanisms whch enable salt-tolerant individuals to survive short-term inundation, gas exchange and water relations parameters were measured before and during a 5-day watering treatment of half-strength synthetic seawater in plants from a tolerant and a non-tolerant population. Photosynthetic recovery was followed for 10 days after the salinity treatment. Photosynthetic CO2 uptake was substantially inhibited in both populations. Stomatal conductances decreased and intercellular CO2 concentrations increased, indicating non-stomatal factors were primarily responsible for the decrease in CO2 uptake. After termination of the salinity treatment photosynthetic capacity increased more rapidly in the tolerant population and reached the pretreatment level after 6 days, whereas the nontolerant population did not recover fully after 10 days. A-Ci curves measured before and after the salinity treatment indicated a decrease in the carboxylation efficiency, and suggested a proportionately greater metabolic inhibition relative to the increase in the stomatal limitation. Osmotic adjustment occurred in a 2-day period in the tolerant population, but there was no change in the osmotic potentials or the water potential at the point of turgor loss in the nontolerant population. Thus short-term salt tolerance in the marsh population is associated with rapid osmotic adjustment and recovcry of photosynthetic capacity shortly after the end of the salinity exposure, rather than maintenance of greater photosynthesis during the salinity treatment.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...