NSFDEB-NERC:Tropical deadwood carbon fluxes: Improving carbon models by incorporating termites and microbes

NSFDEB-NERC：热带枯木碳通量：通过结合白蚁和微生物改进碳模型

• 批准号: NE/R012342/1
• 负责人: Paul Eggleton
• 金额: $ 30.7万
• 依托单位: Natural History Museum
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FR012342%2F1
• 关键词: NSFDEB; NERC; Tropical; deadwood; carbon

Objectives of this project are to measure rates of tropical deadwood (coarse woody debris;CWD) turnover and identify mechanisms that determine fates of CWD carbon (C) under currentand future climates. Woody plants are the largest aboveground terrestrial biotic C store,and CWD biomass is likely substantial but poorly estimated. Much of our knowledge of turnovercomes from temperate systems, where CWD is thought to be slow cycling. Less is known abouttropical CWD pools and turnover, despite large living tree biomass. Due to differences inclimate (warmer temperatures and sometimes greater precipitation), wood construction, andloss pathways (increasing role of termites), it is likely that CWD is dynamic in tropicalsystems. This project combines field, molecular, and modeling approaches in tropical Australia,where termites and fungi are key agents of wood turnover. A continuous belt of forest fromrainforest to savanna with existing long-term data and infrastructure makes it an ideal location.Three questions will be addressed: Q1. What controls rates of CWD C turnover? Turnover rateswill be determined by termite and fungal activity, which are dependent on climate and woodconstruction. Warmer and wetter conditions should increase turnover, but termites should increaseturnover relatively more in dry conditions as they have water conservation strategies. Densehighly lignified wood should decay more slowly. Q2. What controls fates of C from CWD? C fates(CO2, CH4, organic residues) will depend on stage of decay and functional composition of termiteand microbial communities. Later stages of decay, increased methanogens, decreased methanotrophsand changes in termite species should result in greater CH4:CO2. Greater organic residue formationwill occur when C loss is via termites. Q3. How do mechanisms of wood turnover scale up toaffect ecosystem-level C fluxes under climate change? Climate warming in Northern Australiawill increase turnover rates and alter C fates of wood. To date, CWD is poorly parameterizedin Earth system models (e.g., CWD decays only via physical fragmentation). Field data fromQ1 and Q2 will be used to drive new predictive models of wood turnover and greenhouse gas(GHG) production under climate change. To test Q1 and determine relative saprobic microbeand termite decay rates in response to precipitation variation, blocks of a novel substrate(Pinus radiata) known to attract termites will be placed at 6 sites (Rainfall gradient experiment).Blocks will be enclosed in fine-mesh with or without holes manipulating termite access; blockswill be harvested at end of wet and dry seasons for 4 years. To determine influence of woodconstruction on decay, replicate logs of 10 species/site similarly enclosed will be placedat rainforest and savannah sites (Common garden experiment). Logs will be harvested at endof 2 wet and 2 dry seasons. For logs/blocks, initial and final mass, density and chemistrywill be measured. Local weather stations will provide climate data. To test Q2, wood subsamplesand termites in wood will be collected to determine termite community, microbial communityand functional gene composition, and organic residue formation. CO2 and CH4 will be measuredfor harvested logs/blocks. As some termites live in mounds, experimental mounds (Termite mesocosmexperiment) will be established and mound diel CO2 and CH4 fluxes will be measured monthlyfor 1 yr. To test Q3, field data will be incorporated into woodCLM, an ecosystem model derivedfrom the Community Land Model. Results from the modified and original models will be compared.Using woodCLM, wood dynamics and GHG emissions will be simulated under future climate scenarios

该项目的目标是测量热带枯木（粗木屑；CWD）的周转率，并确定确定当前和未来气候下 CWD 碳 (C) 命运的机制。木本植物是最大的地上陆地生物碳库，CWD 生物量可能很大，但估计不足。我们对周转的大部分了解都来自于温带系统，在这些系统中，CWD 被认为是缓慢循环的。尽管活树生物量很大，但对热带 CWD 池和周转率知之甚少。由于气候（气温升高，有时降水较多）、木结构和损失途径（白蚁作用增强）的差异，CWD 在热带系统中很可能是动态的。该项目结合了澳大利亚热带地区的实地、分子和建模方法，白蚁和真菌是澳大利亚热带地区木材周转的关键因素。从雨林到稀树草原的连续森林带以及现有的长期数据和基础设施使其成为理想的地点。将解决三个问题： Q1。是什么控制着 CWD C 的周转率？周转率将由白蚁和真菌活动决定，而白蚁和真菌活动又取决于气候和木结构。温暖和潮湿的条件应该会增加周转率，但白蚁在干燥条件下应该相对更多地增加周转率，因为它们有节水策略。致密的高度木质化木材腐烂得更慢。 Q2。是什么控制着 CWD 的命运？ C 的命运（CO2、CH4、有机残留物）将取决于腐烂阶段以及白蚁和微生物群落的功能组成。腐烂的后期阶段、产甲烷菌增加、甲烷氧化菌减少以及白蚁种类的变化会导致更多的 CH4:CO2。当白蚁造成碳损失时，会形成更多的有机残留物。 Q3。气候变化下木材周转机制如何扩大影响生态系统水平的碳通量？澳大利亚北部的气候变暖将增加周转率并改变木材的碳命运。迄今为止，CWD 在地球系统模型中的参数化很差（例如，CWD 仅通过物理碎片衰减）。第一季度和第二季度的现场数据将用于推动气候变化下木材周转和温室气体（GHG）产生的新预测模型。为了测试 Q1 并确定腐生微生物和白蚁随降水变化的相对腐烂率，已知能吸引白蚁的新型基质（辐射松）块将被放置在 6 个地点（降雨梯度实验）。块将被封闭在细网中，有或没有操纵白蚁进入的孔；区块将在 4 年的雨季和旱季结束时收获。为了确定木结构对腐烂的影响，将在雨林和热带草原地点放置 10 个物种/地点的复制原木，同样封闭（共同花园实验）。原木将在 2 个雨季和 2 个旱季结束时收获。对于原木/块，将测量初始和最终质量、密度和化学成分。当地气象站将提供气候数据。为了测试Q2，将收集木材子样本和木材中的白蚁，以确定白蚁群落、微生物群落和功能基因组成以及有机残留物形成。将测量收获的原木/木块的二氧化碳和甲烷。由于一些白蚁生活在土丘中，因此将建立实验土丘（Termite mesocosmexperiment），并在一年内每月测量土丘昼夜二氧化碳和甲烷通量。为了测试第三季度，现场数据将被纳入 woodCLM，这是一个源自社区土地模型的生态系统模型。将比较修改后的模型和原始模型的结果。使用 woodCLM，将在未来的气候情景下模拟木材动态和温室气体排放

项目成果

Effects of land use and soil properties on taxon richness and abundance of soil assemblages

• DOI: 10.1111/ejss.13430
• 发表时间: 2023-11
• 期刊: European Journal of Soil Science
• 影响因子: 4.2
• 作者: Victoria J Burton;A. Baselga;A. Palma;Helen R. P. Phillips;Christian Mulder;Paul Eggleton;Andy Purvis

Earthworm distributions are not driven by measurable soil properties. Do they really indicate soil quality?

• DOI: 10.1371/journal.pone.0241945
• 发表时间: 2021
• 期刊: PloS one
• 影响因子: 3.7
• 作者: Hodson ME;Corstanjeb R;Jones DT;Witton J;Burton VJ;Sloan T;Eggleton P
• 通讯作者: Eggleton P

Land use and soil characteristics affect soil organisms differently from above-ground assemblages.

• DOI: 10.1186/s12862-022-02089-4
• 发表时间: 2022-11-17
• 期刊: BMC ecology and evolution
• 影响因子: 2.2

Shifts in internal stem damage along a tropical precipitation gradient and implications for forest biomass estimation.

内部茎损伤沿热带降水梯度的变化及其对森林生物量估计的影响。

• DOI: 10.1111/nph.19417
• 发表时间: 2023
• 期刊: The New phytologist
• 作者: Flores-Moreno H

Assessing the Australian Termite Diversity Anomaly: How Habitat and Rainfall Affect Termite Assemblages

• DOI: 10.3389/fevo.2021.657444
• 发表时间: 2021-04-23
• 期刊: FRONTIERS IN ECOLOGY AND EVOLUTION
• 影响因子: 3
• 作者: Clement, Rebecca A.;Flores-Moreno, Habacuc;Zanne, Amy E.
• 通讯作者: Zanne, Amy E.