Herbivory and warming have opposing short‐term effects on plant‐community nutrient levels across high‐Arctic tundra habitats
Herbivory and warming have opposing short‐term effects on plant‐community nutrient levels across high‐Arctic tundra habitats
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食草和变暖对北极苔原高栖息地的植物群落营养水平具有相反的短期影响
DOI：
10.1111/1365-2745.14114
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发表时间：
2023
影响因子：
5.5
通讯作者：
Jónsdóttir, Ingibjörg Svala
中科院分区：
文献类型：
--
作者：
Petit Bon, Matteo;Bråthen, Kari Anne;Ravolainen, Virve Tuulia;Ottaviani, Gianluigi;Böhner, Hanna;Jónsdóttir, Ingibjörg Svala
环境变化可以迅速改变冻土带植物群落的常绿生物量；然而，它们能在多大程度上改变植物群落的营养水平？营养水平及其变化可以影响生物量、养分循环速率和草食动物的养分有效性。我们研究了环境扰动如何改变北极植物群落叶片养分浓度（干质量百分比，即资源质量）和养分池（单位面积绝对质量，即资源量）。我们在斯瓦尔巴群岛的高北极生态系统中实验施加了两种不同类型的环境扰动，跨越了土壤湿度和植物群落组成不同的三个栖息地。我们既模拟了脉冲扰动（春天鹅的觅食事件），也模拟了压力扰动（恒定水平的夏季变暖）。经过2年的扰动，我们量化了最丰富的维管植物物种的1268个叶片样品的氮和磷的高峰季节浓度。我们得到了整个植物群落和单个植物功能类型（pft）的群落加权营养浓度和营养总量（池）。春季蛴螬增加了湿润生境（+13%）和湿润生境（+8%）的植物群落养分浓度，但没有增加湿润生境，并减少了所有生境的养分池（湿润生境：- 49%；湿润生境，湿润生境：- 31%至- 37%）。相反，夏季变暖使湿润生境和湿润生境的植物群落营养物质浓度降低（- 10% ~ - 12%），而湿润生境的植物群落营养物质浓度没有降低（+50%）。快速生长的PFTs表现出营养浓度响应，而缓慢生长的PFTs通常没有。啃食提高了湿润生境牧草和牧草的养分浓度（+20%），提高了湿润生境马尾草和牧草的养分浓度（+ 19-23%）。相反，变暖降低了湿润生境中马尾的养分浓度（- 15%），湿润生境中草、马尾和草本的养分浓度（- 12%至- 15%）。尽管最丰富的PFT对扰动有反应，但每个PFT所持有的营养池受到的影响较小。北极植物群落的营养水平可能会因环境变化而迅速改变，从而影响短期过程速率和植物与食草动物的相互作用。不同生境和PFTs对营养物浓度和池的群落水平响应相反且存在差异。我们的发现对我们如何理解由草食和变暖引起的苔原栖息地内部和之间资源质量和数量精细分布的变化具有启示意义。
Environmental changes can rapidly alter standing biomass in tundra plant communities; yet, to what extent can they modify plant‐community nutrient levels? Nutrient levels and their changes can affect biomass production, nutrient cycling rates and nutrient availability to herbivores. We examined how environmental perturbations alter Arctic plant‐community leaf nutrient concentrations (percentage of dry mass, i.e. resource quality) and nutrient pools (absolute mass per unit area, i.e. resource quantity).We experimentally imposed two different types of environmental perturbations in a high‐Arctic ecosystem in Svalbard, spanning three habitats differing in soil moisture and plant‐community composition. We mimicked both a pulse perturbation (a grubbing event by geese in spring) and a press perturbation (a constant level of summer warming).After 2 years of perturbations, we quantified peak‐season nitrogen and phosphorus concentrations in 1268 leaf samples from the most abundant vascular plant species. We derived community‐weighted nutrient concentrations and total amount of nutrients (pools) for whole plant communities and individual plant functional types (PFTs).Spring grubbing increased plant‐community nutrient concentrations in mesic (+13%) and wet (+8%), but not moist, habitats, and reduced nutrient pools in all habitats (moist: −49%; wet, mesic: −31% to −37%). Conversely, summer warming reduced plant‐community nutrient concentrations in mesic and moist (−10% to −12%), but not wet, habitats and increased nutrient pools in moist habitats (+50%).Fast‐growing PFTs exhibited nutrient‐concentration responses, while slow‐growing PFTs generally did not. Grubbing enhanced nutrient concentrations of forbs and grasses in wet habitats (+20%) and of horsetails and grasses in mesic habitats (+19–23%). Conversely, warming decreased nutrient concentrations of horsetails in wet habitats (−15%) and of grasses, horsetails and forbs in moist habitats (−12% to −15%). Nutrient pools held by each PFT were less affected, although the most abundant PFTs responded to perturbations.Synthesis. Arctic plant‐community nutrient levels can be rapidly altered by environmental changes, with consequences for short‐term process rates and plant‐herbivore interactions. Community‐level responses in nutrient concentrations and pools were opposing and differed among habitats and PFTs. Our findings have implications for how we understand herbivory‐ and warming‐induced shifts in the fine‐scaled distribution of resource quality and quantity within and across tundra habitats.
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影响因子：
5.2
作者：
Judith Sitters;M. Chérif;Dagmar D. Egelkraut;R. Giesler;J. Olofsson
通讯作者：
Judith Sitters;M. Chérif;Dagmar D. Egelkraut;R. Giesler;J. Olofsson
放牧和全球变暖对格陵兰岛东部蜕皮鹅禾本科沼泽的组成和承载能力的长期影响
影响因子：
6.5
作者：
J. Madsen;C. Jaspers;M. Tamstorf;C. Mortensen;F. Rigét
通讯作者：
F. Rigét
影响因子：
6.4
作者：
Kai Yue;Yan Peng;D. Fornara;Koenraad Van Meerbeek;L. Vesterdal;Wanqin Yang;C. Peng;B. Tan;W. Zhou
通讯作者：
Kai Yue;Yan Peng;D. Fornara;Koenraad Van Meerbeek;L. Vesterdal;Wanqin Yang;C. Peng;B. Tan;W. Zhou
影响因子：
3.7
作者：
L. Street;Nora Mielke;S. Woodin
通讯作者：
L. Street;Nora Mielke;S. Woodin
影响因子：
5.5
作者：
Jefferies, RL;Jano, AP;Abraham, KF
通讯作者：
Abraham, KF