Long-term and interactive effects of seaweed diversity and herbivory on intertidal community structure and functioning

海藻多样性和草食性对潮间带群落结构和功能的长期交互影响

• 批准号: 0850707
• 负责人: John Stachowicz
• 金额: $ 52.26万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-03-01 至 2014-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0850707&HistoricalAwards=false
• 关键词: Long; term; interactive; effects; seaweed

Stimulated in part by rapid changes in the biological composition and richness of most of Earth's ecosystems, considerable theoretical and empirical research has focused on understanding the effects of species richness on communities and ecosystems. This research has resulted in major advances and has shown that diversity can affect ecosystem processes. However, we are currently limited in our ability to draw generalities regarding these effects that transcend ecosystems and to apply this knowledge to conservation and management efforts because: (1) most experiments are of short duration and relatively few are conducted under field conditions on natural substratum; and (2) most experiments manipulate only diversity and so cannot assess the strength of diversity relative to other known drivers of ecosystem functioning. Previous NSF-funded work found that species diversity of seaweeds does increase the accumulation of producer biomass and the diversity and richness of mobile invertebrates associated with those seaweeds. In this project, the investigator will examine the interactive effects of plant and grazer richness on seaweed productivity and assemblage recovery from disturbance by (a) continuing our ongoing diversity manipulations (b) nesting additional experiments manipulating grazers within these plots, and (c) performing new experiments to examine effects of grazer richness on algal assemblages. The main experiment consists of 72 1.5 m diameter plots in the rocky intertidal at Bodega Bay, California, split into 6 different treatments: a monoculture of each of the 4 algal species that comprise 85% of the algal cover in our system; a 4-species polyculture, and an unmanipulated control plot. The PI created these "diversity" plots by weeding under the auspices of a previous NSF grant. Objectives of this project are: (1) To nest within the diversity plots smaller cleared areas that either allow or prohibit access by grazers in order to test the interactive effects of algal diversity and herbivory on recovery of the algal assemblage from disturbance (or resilience). (2) To conduct a separate combined additive and replacement series experiment to examine the effects of herbivore identity and richness on algal recruitment and succession. (3) While the nested grazer-exclusion experiment is in progress, to continue weeding and collecting data in the uncleared portion of these plots as a continued test of the univariate effect of algal richness on the cover of algae and sessile invertebrates, and on mobile invertebrate abundance, richness, and diversity. Together with previous results, this will produce a 7 year record of the effects of seaweed richness on rocky intertidal communities, which will then be correlated with archived environmental data. (4) After the nested grazer exclusion experiment is complete, to cease weeding plots and track their reinvasion by weeded species in order to evaluate the mechanisms maintaining diversity of perennial algae.Understanding the consequences of simultaneous changes in grazer abundance or diversity and algal diversity as well as the long-term effects of both on the resilience of algal communities in the face of disturbance will provide a better understanding of both the consequences of human encroachment into these habitats and the appropriate management efforts needed to minimize impacts and maintain ecosystem functioning. This is especially critical given that harvesting and trampling by humans are altering the diversity and composition of herbivores and algae in the California rocky intertidal zone. The PI recently briefed legislative and agency staff in California on the results of previous NSF work on the consequences of marine biodiversity, so there is interest from policymakers. The PI will continue to work with outreach groups like COMPASS and the Aldo Leopold Leadership Program to help disseminate the findings of this research as broadly as possible to the general public and decision-makers. In addition, through outreach efforts such as the Bodega Marine Lab Open House and visits to local schools the investigator will continue to foster public understanding of the importance of maintaining biodiversity and more generally of how science works. Finally, this project will develop future scientists including a technician, graduate and undergraduate researchers including those from underrepresented groups.

大多数地球生态系统的生物组成和丰富性的快速变化所激发，大量的理论和经验研究集中在理解物种丰富度对社区和生态系统的影响上。这项研究取得了重大进展，并表明多样性会影响生态系统过程。但是，目前，我们对超越生态系统的这些影响并将这些知识应用于保护和管理工作的能力的能力有限，因为：（1）大多数实验的持续时间很短，在自然基质的现场条件下进行了相对较少的实验； （2）大多数实验仅操纵多样性，因此无法评估相对于其他已知生态系统功能的驱动因素的多样性强度。以前由NSF资助的工作发现，海藻的物种多样性确实增加了生产者生物量的积累以及与这些海藻相关的流动无脊椎动物的多样性和丰富性。在该项目中，研究人员将检查植物和掠夺者丰富度对（a）继续我们正在进行的多样性操纵（b）在这些图中操纵Grazer的其他实验的互动效果，并从干扰中恢复组合恢复，以及（c）执行新的实验，以检查Grazer Richness对Grazer Richness对Algal组装的影响。主要实验由加利福尼亚州博德加湾的岩石间带中的72 1.5 m直径组成，分为6种不同的治疗方法：四个藻类物种中每种物种的单一培养物，占我们系统中藻类覆盖的85％；一个4种多养殖和无操纵的控制图。 PI通过在先前的NSF赠款的主持下除草来创建这些“多样性”图。该项目的目标是：（1）嵌套在多样性中筑巢较小的清除区域，这些区域允许或禁止放牧者访问，以测试藻类多样性和食草动物对从干扰（或弹性）中恢复藻类组合的交互作用。 （2）进行单独的组合添加剂和替代系列实验，以检查草食动物身份和丰富性对藻类募集和继承的影响。 （3）虽然正在进行嵌套的Grazer排斥实验，但仍在这些地块的未清除部分中继续除草并收集数据，以继续测试藻类丰富度对藻类和无脊椎动物封面的单变量效应，以及在移动的无脊椎动物无危险，丰富的，丰富的，富裕，多样性，以及多样性的无脊椎动物上。再加上先前的结果，这将产生7年的海藻丰富度对岩石潮间带社区的影响，然后将与存档的环境数据相关。 （4）在完成嵌套的掠夺者排除实验之后，停止除草地块并通过除草物种的重新攻击，以评估维持多年生藻类多样性的机制。理解同时变化的后果是，掠夺者多样性或藻类多样性的长期影响力以及对alg的长期影响的影响，以及alg的长期影响力的长期影响力，并在alg g的长期上产生了良好的影响力，而alg的脉络性则是在alg的影响方面的发展。人类侵占这些栖息地的后果以及最小化影响并维持生态系统功能所需的适当管理工作。鉴于人类的收获和践踏正在改变加利福尼亚洛矶岩岩层潮间带的多样性和组成，这一点尤其重要。 PI最近向加利福尼亚州的立法和机构工作人员简要介绍了NSF关于海洋生物多样性的后果的结果，因此政策制定者有兴趣。 PI将继续与Compass和Aldo Leopold领导力计划等外展小组合作，以帮助将这项研究的发现尽可能广泛地传播给公众和决策者。此外，通过诸如Bodega Marine Lab Open House之类的外展工作以及对当地学校的访问，调查员将继续公众了解维持生物多样性的重要性以及更广泛地了解科学的工作原理。最后，该项目将发展未来的科学家，包括技术人员，研究生和本科研究人员，包括来自代表性不足的团体的研究人员。