Fronds to forests: Individual-based and whole-forest models of kelp

在一些国家，特别是远东地区，收获海藻以获取生物燃料、化肥以及提取用于人类和动物食品产品以及药品的化学品是一项重要的产业。在东北大西洋地区，只有在法国和挪威才会使用专用船只进行大量捕捞。挪威每年的收成超过10万吨。据估计，苏格兰水域的海带(主要是海带)的生物量超过2,000万吨2，在1970年的S-1990年的S时期，西岛发展了每年10,000-15,000吨的捕捞产业。然而，目前的收获仅限于少数生产特色产品的手工捕捞企业，最近关于机械收获的提议已被苏格兰政府拒绝，等待彻底审查。反对在苏格兰的地点机械捕捞海带似乎更多的是出于一种预防方法，而不是基于任何关于大规模不利后果的具体科学证据，至少从预期的收获规模来看是这样。事实上，尽管从法国和挪威的经验中有大量关于有效收获战略的经验知识，但对海藻森林动态的科学理解明显不足。海带是一种生理复杂的植物，寿命相对较长(根据物种的不同，最长可达10年)，能够储存大量的氮，并将大量的多糖排泄到环境中。森林为各种无脊椎动物和脊椎动物物种提供了密集的栖息地，森林的动态取决于一系列环境因素，例如浑浊、温度和波浪暴露，以及依赖密度的调节过程，例如代际竞争空间(定居孢子需要安全的表面才能保持快速发育)，以及自我遮荫竞争光线。在这个项目中，我们将开发适合苏格兰水域的海藻森林动态的数学模型，然后可以用来探索自然变异性和采伐对森林生物量和更新的影响。我们将从两个方向来解决这个问题--使用全森林生物量和性质的模型，以及基于个体的相互作用植物模型。文献3、4中存在的少数海藻动态模型通常是对单个植物的发育(生长和存活)进行建模，然后假定这是森林发展的同义词。然而，事实并非如此。博士项目的任务将是：-从Creran湖5的历史数据遗产开始，为苏格兰各地的一系列水井研究地点开发、测试森林和基于个体的模型并将其参数化。-进行模型实验，以确定整个森林模型能够模拟基于个体的模型的行为的程度以及在什么条件和参数值下。-用模型进行实验，以确定最优的采伐策略，以确保未来可持续的森林生物量和结构1 Capuzzo，E.和McKie，T.(2016)。海藻在英国和国外的现状、产品、限制、差距和Cefas的作用。CEFAS合同报告FC002I。78pp.2Burrow et al.(2018)野生海藻收获为渔民提供了多样化的机会。SRSL关于HIE的报告，1713Aldridge，J.，van de Molen，J.和Forster，R.(2012)。大型藻类养殖的更广泛的生态影响。《皇室财产》，95页4 Broch，O.J.和Slagstad，D.(2012年)。模拟海带的季节生长和组成。J.Appl.菲科尔。约翰斯顿，C.S.，琼斯，R.G.和亨特，R.D.(1977)。苏格兰海湖的季节性碳收支。赫尔戈兰德·威斯。

Harvesting of seaweeds for biofuel, fertiliser, and extraction of chemicals for human and animal food products, and pharmaceuticals, is a significant industry in some countries especially the Far East1. In the northeast Atlantic region, significant harvesting involving dedicated vessels occurs only in France and Norway. The annual Norwegian harvest is more than 100,000 tonnes. The biomass of kelp (mainly Laminaria hyperborea) in Scottish waters is estimated to be in excess of 20 million tonnes2, and a 10,000-15,000 tonne per annum harvesting industry developed in the Western Isles during the 1970's-1990's. However, the current harvesting is confined to a small number of hand-harvesting businesses producing speciality products, and recent proposals for mechanical harvesting have been rejected by the Scottish Government pending a thorough review. Opposition to mechanical harvesting of kelp at sites in Scotland appears to be motivated more by a precautionary approach, and not based on any specific scientific evidence of large scale adverse consequences, at least from the scale of harvesting that is envisaged. In fact, although there is ample experience-based knowledge on effective harvesting strategies from French and Norwegian experiences, scientific understanding of kelp forest dynamics is markedly lacking. Kelp are relatively long-lived (up to 10 years depending on species) physiologically complex plants, able to store significant reserves of nitrogen, and excrete quantities of polysaccharides into the environment. Forests provide a dense habitat for a wide range of invertebrate and vertebrate species, and forest dynamics depend on a range of environmental factors such as turbidity, temperature and wave exposure, and density-dependent regulatory process such as inter-generational competition for space (settling spores require a secure surface for holdfast development), and self-shading competition for light. These density dependent processes are exactly the ones that may mitigate or accentuate any effects of harvesting on the forests.In this project we will develop mathematical models of kelp forest dynamics appropriate to Scottish waters that can then be used to explore the consequences of natural variability and harvesting on forest biomass and regeneration. We will approach the problem from two directions - using models of whole-forest biomass and properties, and individual-based models of interacting plants. The few models of kelp dynamics that exist in the literature3,4 generally model the development (growth and survival ) of individual plants, and then assume that this is synonymous with forest development. However, this is not necessarily the case.The task of the PhD project will be to:-Develop, test and parameterise both the forest and individual-based models for a range of well studies sites around Scotland, starting with the legacy of historical data from Loch Creran5.-Conduct model experiments to determine the extent, and under what conditions and parameter values, the whole-forest model is able to simulate the behaviour of the individual-based models.-Conduct experiments with the models to determine the optimum harvesting strategy to ensure sustainable forest biomass and structure into the future1Capuzzo, E. and McKie, T. (2016). Seaweed in the UK and abroad - status, products, limitations, gaps and Cefas role. Cefas contract report FC002I. 78pp.2Burrows et al. (2018) Wild Seaweed Harvesting as a Diversification Opportunity for Fishermen. A report by SRSL for HIE, pp. 1713Aldridge, J., van de Molen, J. and Forster, R. (2012). Wider ecological implications of Macroalgae cultivation. The Crown Estate, 95 pp.4Broch, O.J. and Slagstad, D. (2012). Modelling seasonal growth and composition of the kelp Saccharina latissimi. J. Appl. Phycol. 24, 759-776.5Johnston, C.S., Jones, R.G. and Hunt, R.D. (1977). A seasonal carbon budget for a laminarian population in a Scottish sea-loch. Helgolander Wiss.