摘要
草坪蒸散量是指导草坪合理灌溉的重要指标。自 2 0世纪中叶以来 ,以节水为目的的草坪蒸散研究越来越受到人们的重视。草坪蒸散研究的内容主要包括相互关联的 3个方面 :草坪蒸散率的测定与比较 ,草坪蒸散机制的研究和草坪节水灌溉的研究。草坪蒸散率在不同草种间存在不同程度的差异。暖季型草坪草和冷季型草坪草相比普遍具有较低的草坪蒸散率。暖季型草坪草的夏季日平均最大蒸散率为 3.0～9.0 mm,而冷季型草坪草的为 3.6～ 1 2 .6mm。密度大 ,生长缓慢的杂交狗牙根、结缕草、野牛草和假俭草的耗水量很低 ,细羊茅的耗水量中等 ,而草地早熟禾、高羊茅、1年生早熟禾和匍匐剪股颖的耗水量很大。同种草坪草的不同品种的草坪蒸散率存在差异。有些草种内品种间差异的程度高达 64% ,不亚于种间。冷季型草坪草品种的蒸散率与留茬量显著相关 ,但环境因子对品种的蒸散率影响很大 ,品种的蒸散特性不稳定。与冷季型草坪草相比 ,暖季型草坪草的种内品种间蒸散率的差异程度较小。草坪的冠层是草坪蒸散的一个主要外部条件 ,具有较低蒸散率的草坪往往具备高冠层阻力和低叶面积。土壤水分不受限制时 ,不同的暖季型草坪草种间的草坪蒸散率与叶片背面的气孔密度显著负相关。但在种内品种间没有表现出相关性。
Turfgrass evapotranspiration (ET) is an important index for turfgrass irrigation. Since the middle of the 20 th century, more and more studies of turfgrass ET have been conducted because of the shortage of water for irrigating turfgrass. The content of turfgrass ET research mainly include three aspects that related to each other: (i)Turfgrass ET rate measurement and comparison. (ii)Turfgrass ET mechanism study. (iii) Turfgrass water conservation study. There are major differences in the ET rates among most turfgrass species. Cool-season turfgrass species have higher ET rates than warm-season species. The range of ET rates for cool-season turfgrasses is 2.7 to 12.6 mm·d -1 as compare to 3.0 to 10.0 mm·d -1 for warm-season species. For cool-season species, the fine-leafed fescue ranked medium, while Kentucky bluegrasss, annual bluegrasss, and creeping bentgrass exhibited very high ET rates. For warm-season turfgrasses, high density, low growing species, such as hybrid bermudagrass, zoysiagrass, buffalograss, and centipedegrass, exhibited the lowest ET rates. The ET rates are also different on the intraspecific level. Reported ET rates for Kentucky bluegrasss cultivars differed by as much as 64%, as great as that encountered at the interspecific level. Verdure is significantly correlated to ET rates of cool-season cultivars, but the intraspecific ET characterizations of turfgrass are variable between diverse evaporative environments. For warm-season species, the intraspecific ET difference is smaller as compare to cool-season turfgrass. Canopy characteristic is an important external factor that influences turfgrass ET. Turfgrasses with comparatively lower ET rates are generally characterized by having a high canopy resistance and a low leaf area. Under nonlimiting moisture conditions, there is a significant negative correlation between ET rate and abaxial stomata density on the interspecific level for warm-season species, but no correlation on intraspecific level. For cool-season turfgrass, stomata density is not reliably associated with ET rate both on inter and intraspecies. The crop coefficient is a key index to decide the optimum irrigation rate for turfgrass. The turfgrass crop coefficient based on Line-Source Irrigation System is more practical than that based on mini-lysimeter measurement. Research indicates that the crop coefficient of Kentucky bluegrasss ranged from 0.60 to 0.80, and 0.50 to 0.80 for tall fescue, based on 1982 Kimberly-Penman equation estimates of potential ET, while maintaining acceptable turfgrass quality. And the significance of turfgrass ET study in China was emphasized. Crop water stress index (CWSI) based on canopy temperature is a reasonable index for irrigation timing. This is however variable because of the different turfgrass species and different seasons, and water conservation capacity also changeable. There is almost no turfgrass ET research in China untill now; the significance of turfgrass evapotranspiration study in China should be emphasized.
出处
《生态学报》
CAS
CSCD
北大核心
2003年第1期148-157,共10页
Acta Ecologica Sinica
基金
北京市自然科学基金资助项目 ( 60 0 1 0 0 1 )
中美合作草坪养护管理研究项目
由俄勒冈种子理事会 ( OSCMAP)资助~~
关键词
草坪蒸散
研究进展
冠层特征
暖季型草坪草
冷季型草坪草
草坪合理灌溉
turfgrass evapotranspiration
turfgrass evapotranspiration rate
canopy character
cool-season turfgrass
warm-season turfgrass
turfgrass irrigation
