Seasonal bryophyte productivity in the sub-Arctic: a comparison with vascular plants
Seasonal bryophyte productivity in the sub-Arctic: a comparison with vascular plants
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亚北极季节性苔藓植物生产力：与维管植物的比较
DOI：
10.1111/j.1365-2435.2011.01954.x
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发表时间：
2012
影响因子：
5.2
通讯作者：
Street L
中科院分区：
文献类型：
--
作者：
Street L
1.北极生态系统正在经历快速的气候变化，如果生态系统的碳(C)损失超过植物生长对C的吸收，可能会导致气候变暖的正反馈。苔藓植物（苔藓、苔类植物和角苔类植物）是北极植被的重要组成部分，但目前在陆地C模式中没有得到很好的体现；特别是，与维管植物植被相比，苔藓植物C代谢的季节模式尚不清楚。我们的目标是量化春季（3 - 5月）和夏季生长期（6 - 8月）亚北极地区常见苔藓植物斑块（以polytrichum piliferumandSphagnum fuscum为主）的陆地-地表co2通量，并建立苔藓植物总初级生产力通量（PB）的简单模型。我们使用该模型来探索pbforp的关键环境控制。piliferumandS。2 .对同一地点典型维管植物群落生产力的季节分布进行了比较。p . 1年（3 - 11月）的模型总初级生产力（ΣPB）。piliferumwasc。360g cm−2研磨，用于s。熔点：112g cm - 2，c。同年典型维管植物群落总初级生产力的90%和30% （ΣPV）。春季（3 - 5月），维管植物叶片发育不完全，ΣPBforP。毛蕊为3 × ΣPV.4。模型敏感性分析表明（3 - 11月）苔藓植被对草皮含水量影响不显著ΣPBforP。piliferumandS。至少在没有持续降水的时期是这样。然而，我们发现苔藓植物光合能力的季节变化在确定ΣPBfor两种苔藓植物种类中都很重要。我们的研究表明，如果要预测生长季节的变化或植被组成的变化对北极碳平衡的影响，北极的碳动态模型必须包括苔藓植物成分。
1.Arctic ecosystems are experiencing rapid climate change, which could result in positive feedbacks on climate warming if ecosystem carbon (C) loss exceeds C uptake through plant growth. Bryophytes (mosses, liverworts and hornworts) are important components of Arctic vegetation, but are currently not well represented in terrestrial C models; in particular, seasonal patterns in bryophyte C metabolism compared to vascular plant vegetation are poorly understood.2.Our objective was to quantify land‐surface CO2fluxes for common sub‐Arctic bryophyte patches (dominated byPolytrichum piliferumandSphagnum fuscum)in spring (March–May) and during the summer growing season (June–August) and to develop a simple model of bryophyte gross primary productivity fluxes (PB). We use the model to explore the key environmental controls overPBforP. piliferumandS. fuscumand compare seasonal patterns of productivity with those of typical vascular plant communities at the same site.3.The modelled total gross primary productivity (ΣPB) over 1 year (March – November) forP. piliferumwasc. 360 g C m−2ground and forS. fuscum c. 112 g C m−2ground,c. 90% and 30% of total gross primary productivity for typical vascular plant communities (ΣPV) over the same year. In spring (March–May), when vascular plant leaves are not fully developed, ΣPBforP. piliferumwas 3 × ΣPV.4.Model sensitivity analysis indicated that bryophyte turf water content does not significantly affect (March–November) ΣPBforP. piliferumandS. fuscum, at least for periods without sustained lack of precipitation. However, we find that seasonal changes in bryophyte photosynthetic capacity are important in determining ΣPBfor both bryophyte species.5.Our study implies that models of C dynamics in the Arctic must include a bryophyte component if they are intended to predict the effects of changes in the timing of the growing season, or of changes in vegetation composition, on Arctic C balance.