Journal ArticleDOI
Germination and seedling establishment in California annual grassland.
TLDR
Comparison of depletion of the seed-bank in the soil and increase of plant density showed that seeds germinating in the first week of the growing season produced fewer established seedlings than seeds germination in the second or third weeks.Abstract:
(1) Data for plant density, germinable seed in the soil, and seed production in annual grassland were obtained at Hopland Field Station, California, U.S.A., in 1973 and 1974. The study combined indirect estimates of numbers of seed in the soil, germination in soil samples containing natural seed, and estimation of plant density. (2) Autumn patterns of establishment differed significantly between the two study years. Plant density increased through the autumn, reaching peaks of 261 8 and 345*3 plants per dM2 in the seventh week after germination began, in 1973 and 1974 respectively. (3) The numbers of germinable seed in the top 6.4 cm of the soil prior to the start of the growing season were 6705 per dM2 in 1973 and 6102 per dM2 in 1974, and thus showed little difference between years. (4) Comparison of depletion of the seed-bank in the soil and increase of plant density showed that seeds germinating in the first week of the growing season produced fewer established seedlings than seeds germinating in the second or third weeks. The few seeds remaining in the fifth and sixth weeks had a high probability for successful establishment. (5) Six species-groups exhibiting contrasting strategies for germination and establishment are discussed in detail.read more
Citations
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Journal ArticleDOI
Species Interactions Reverse Grassland Responses to Changing Climate
TL;DR: It is shown that, in a California grassland, species interactions strongly influence responses to changing climate, overturning direct climatic effects within 5 years and suggesting a prominent role for species interactions in ecosystem response to climate change.
Journal ArticleDOI
Seasonal variation in carbon dioxide exchange over a Mediterranean annual grassland in California
Liukang Xu,Dennis D. Baldocchi +1 more
TL;DR: In this paper, the authors used the eddy covariance method to measure the flux of CO 2 (F{sub c, flux toward the surface is negative) over a Mediterranean, annual grassland in California, USA for two years.
Journal ArticleDOI
How soil moisture, rain pulses, and growth alter the response of ecosystem respiration to temperature
TL;DR: Xu et al. as mentioned in this paper analyzed 3 years of carbon flux data from continuous eddy covariance measurements to investigate how soil moisture, rain pulses, and growth alter the response of ecosystem respiration to temperature.
Journal ArticleDOI
The Demography of Bromus Tectorum: Variation in Time and Space
Richard N. Mack,David A. Pyke +1 more
TL;DR: Year-to-year variation in environment (weather, predator activity) overrode the intrinsic differences among the three habitat types along a 200 km transect of varying moisture availability often producing considerable amplitude in population attributes (recruitment, survivorship and fecundity).
Journal ArticleDOI
Woody seedling dynamics in an east Texas floodplain forest.
TL;DR: In this article, the relative importance of flooding, drought, fungal attack, herbivory, proximity to a conspecific adult, and shading in causing seedling mortality was estimated.
References
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Journal ArticleDOI
Buried, viable seeds in two California bunchgrass sites and their bearing on the definition of a flora
Jack Major,William T. Pyott +1 more
TL;DR: The soil content of buried, viable seeds in the two stands of Stipa pulchra, bunchgrass vegetation in the eastern foothills of the central Coast Ranges of California is used as a measure of this potential flora.
Journal ArticleDOI
Vegetational changes in the california annual type
TL;DR: The objectives of the study were to describe fluctuations in the California annual type that occur within a growing season and from one year to the next.
Journal ArticleDOI
Terrestrial Vegetation of California.
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