Forest ecosystem functioning in response to wetter winters along a large climatic gradient (WetWin)

森林生态系统根据大气候梯度的冬季天气而发挥作用（WetWin）

• 批准号: 450829734
• 负责人: Professor Dr. Jürgen Kreyling
• 金额: --
• 依托单位: Arbeitsgruppe Experimentelle Pflanzenökologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/450829734?language=en
• 关键词: Forest; ecosystem; functioning; response; wetter

Climate models consistently project moderate to large increases in air temperatures for most temperate ecosystems over the next century, with warming in winter exceeding warming in all other seasons for central and northern Europe. Furthermore, winter precipitation is expected to increase and to shift from snow towards rain. In short, European winters will become warmer and wetter. The net effect of these warmer and wetter winters for ecosystem functioning, however, is unclear.Warmer soils are generally expected to enhance soil biotic activity and nutrient availability for plants. In regions with little natural snow pack and warm winters, this increase in available nutrients will either result in increased plant growth or, in particular if winter precipitation increases, in increased nutrient leaching. Towards colder regions with deeper and longer snow cover, loss of snow may result in colder soil temperatures due to missing insulation by the snow pack, reduced mineralization and decreased plant growth. Here, additional rainfall may exacerbate N limitation due to increased N leaching. The broad objective for this project is the investigation of the importance of winter precipitation for the ecology and biogeochemistry of temperate broad-leaved forests. More specifically, we will test for the effects of increased winter precipitation and its interactions with reduced snow cover. It is hypothesized that effects of nitrogen leaching are stronger at warmer sites, while snow cover change causes stronger responses at colder sites. Therefore, the manipulation experiments will be carried out along a strong climatic gradient which exemplifies climate warming effects from formerly colder and snowier conditions in the east of the gradient to future warmer and less snowy conditions in the west of the gradient. Net ecosystem effects to changes in winter precipitation in tree growth and nitrogen leaching will be quantified and potential effects in these proxies will be explained by the following suite of parameters: (1) soil biotic activity, decomposition, and mineralization; (2) nutrient availability and leaching (3) above and below-ground growth and resource allocation of adult and juvenile individuals of the naturally dominating forest tree of central Europe, i.e. Fagus sylvatica, and understory vegetation. We will identify the relative sensitivities of these ecological and biogeochemical response parameters to winter precipitation change along a large gradient of winter temperature from across Northeastern Germany and northern Poland in order to develop a better understanding of the potential effects on ecosystem functioning and sound up-scaling to future climatic conditions.

气候模型一贯预测，在下个世纪，大多数温带生态系统的气温将出现中等到较大的上升，中欧和北欧冬季的变暖超过其他所有季节的变暖。此外，冬季降水量预计将增加，并从雪转雨。简而言之，欧洲的冬天将变得更温暖、更潮湿。然而，这些更温暖、更潮湿的冬季对生态系统功能的净影响尚不清楚。更多的土壤通常被认为会增强土壤的生物活性和植物的养分有效性。在自然积雪少、冬季温暖的地区，有效养分的增加将导致植物生长增加，特别是如果冬季降雨量增加，则会导致养分淋失增加。对于积雪更深、更长的寒冷地区，积雪的消失可能会导致土壤温度更低，这是因为积雪没有隔热，矿化作用减少，植物生长减少。在这里，额外的降雨量可能会由于增加氮素淋失而加剧氮素限制。该项目的总体目标是调查冬季降水对温带阔叶林生态和生物地球化学的重要性。更具体地说，我们将测试冬季降水增加的影响及其与降雪减少的相互作用。据推测，氮素淋失的影响在较温暖的地点更强，而积雪覆盖的变化在较冷的地点引起更强的反应。因此，操纵实验将沿着一个强烈的气候梯度进行，这表明气候变暖的影响从梯度东部以前更冷和更多雪的条件到未来梯度西部更温暖和更少雪的条件。将量化生态系统对树木生长和氮素淋失的冬季降水变化的净生态系统影响，并将通过以下一组参数来解释这些替代指标中的潜在影响：(1)土壤生物活性、分解和矿化；(2)养分有效性和淋溶；(3)中欧自然优势林木，即青冈和林下植被的成虫和幼虫地上和地下生长和资源分配。我们将确定这些生态和生物地球化学响应参数对德国东北部和波兰北部冬季气温大梯度上冬季降水变化的相对敏感性，以便更好地了解这些参数对生态系统功能的潜在影响，以及对未来气候条件的合理放大。