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Heike Knörzer Karin Hartung Hans‐Peter Piepho Iris Lewandowski 《Global Change Biology Bioenergy》2013,5(5):572-579
To diversify energy crop production and improve its biodiversity and sustainability, there is currently a search for alternative energy crops. Many of the newly arising alternatives are perennial species such as the C4 grass miscanthus. The assessment of reliable data is a prerequisite for understanding the performance of these crops and developing corresponding management systems. However there is great uncertainty concerning research methodology for these crops. When data are collected from small plots of perennial crops, such as miscanthus or short rotation coppice plantations, a larger variability is expected than for cereals. A square meter cut, corresponding to harvest practice in cereals, is not sufficient for perennial C4 grasses and is not recommended for these species. The aim of this research was to identify an adequate size of sampling area for miscanthus to estimate the true biomass yield or quality. For this purpose, whole plots of 10‐ and 14‐year old miscanthus stands were divided into smaller subplots. These were used to calculate variances for various sizes of simulated plots. The variances for all traits in the experiments were rather high when the sampling area was smaller than 2 m². A cutting regime of more than 5.6 m² would be advisable, but an area of 3 m² is sufficient to eliminate approximately 90% of the variances and is therefore an adequate size of sampling area. 相似文献
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C. J. Knüsel 《Human Evolution》1992,7(1):1-7
Fifer (1987) has provided a very useful hypothesis to explain the advent of bipedal gait and locomotion. Through re-focusing
attention on a functional argument centred on throwing behaviour he has invigorated the debate surrounding the origins of
thehominidae. The present article provides evidence of plastic and pathological osteological indicators of throwing that may aid in more
precisely elucidating the timing of this adaptative event and its subsequent development. 相似文献