Gradients of marine biodiversity and linkages with eDNA across the Wallacea Region

生态系统中生物之间的相互依存关系支配着生态功能、对生态系统变化的反应和生态系统服务的提供。复杂的多物种相互作用形成了生态网络，增加了群落的稳定性，众所周知，较高的多样性促进了动态稳定性，并应对了生态系统的压力。了解这些生态网络和动态对多种慢性和急性环境扰动的反应是设计养护干预措施的关键，但在热带海洋系统中，网络动态在很大程度上仍然是未知的。Wallacea地区不仅是全球珊瑚礁多样性的震中，它的珊瑚礁也是数百万人最重要的食物和收入来源。该地区对于维持全球受到威胁的珊瑚礁生物多样性具有全球重要意义，因为它是为数不多的尚未因气候压力事件而经历大规模退化的珊瑚礁之一。然而，这些地区的珊瑚礁受到当地压力因素的极大改变，最明显的是陆源沉积物流失和渔业过度开发。缓解这些地方压力源的管理正在进行中，但由于普遍缺乏数据和了解这些压力源如何影响整个区域的生物多样性及其相互作用，这一管理工作受到了严重阻碍。考虑到当地有限的资源、时间和专业知识，目前Wallacea的大多数珊瑚礁都无法克服缺乏信息来向管理层提供信息的问题。该项目涉及三个目标，需要解决这三个目标以克服这些挑战。首先，我们将使用对珊瑚、大型无脊椎动物和鱼类的传统目测技术来确定基本未受影响、水质下降或下降的生态网络与捕捞地点的不同之处。生态网络将以实地数据为基础，使用新的/尖端的生态建模方法和网络理论进行量化。这一目标最初侧重于容易观察到的非神秘分类群，并将形成我们对EDNA的比较评估的基础，EDNA具有巨大的潜力，但在珊瑚礁系统中仍未得到验证。我们的第二个目标将验证EDNA在描述珊瑚礁生物多样性动态方面的有效性，并首次测试根据EDNA构建的网络与来自生态调查的网络进行比较的情况。结果将提供独特的见解和珊瑚礁监测方法逐步改变的潜力，扩大加强空间和时间采样的机会，同时提供与使用这些新颖的EDNA数据构建的生态网络及其衡量标准相关的置信度限制。最后，在评估了EDNA技术的应用后，我们计划通过从偏远地区进行广泛的EDNA采样来绘制Wallacea珊瑚礁生物多样性图。我们将把EDNA抽样扩展到Wallacea内的另外10个地点，以提供前所未有的空间和生态复杂性规模的新数据，使我们能够在与印尼海洋空间规划最相关的规模上模拟和预测应对人为压力的变化。尽管巨大多样的珊瑚礁生态系统的功能高度冗余，但物种的丧失将改变群落的组成和功能，产生广泛的生态、社会和经济影响。对于复杂系统中的保护工作，在这些系统中，神秘物种采样不足，但发挥着重要的功能作用，现实世界需要了解真实的生物多样性和网络相互作用。我们将开发和测试应对这一挑战的新方法，以便在面对珊瑚礁危机时实现可持续发展。生态网络中的响应动态为群落的稳健性提供了信息，这些信息是管理决策的关键。

The interdependencies among organisms in ecological systems govern ecological function, responses to ecosystem change and the provision of ecosystem services. Complex multi-species interactions form ecological networks that increase community stability, where it is known that higher diversity promotes dynamic stability and counters pressures on the ecosystem. Understanding these ecological networks and dynamics in response to multiple chronic and acute environmental disturbances is key to designing conservation interventions, but network dynamics remain largely unknown in tropical marine systems. The Wallacea region is not only the epicenter of global coral reef diversity, it's coral reefs are also the most important source of food and income for millions of people. The region is globally important for sustaining globally threatened reef biodiversity, because it is one among few reefs that have not yet experienced large-scale degradation due to climate stress events. However, the regions' reefs are greatly transformed by local stressors, most notably terrestrial derived sediment run-off and fisheries overexploitation. Management to mitigate these local stressors is underway, but is severely hampered by a pervasive lack of data and understanding how these stressors affect biodiversity and its interactions throughout the region. Given the limited local resources, time, and expertise, presently the lack of information to inform management will not be overcome for most reefs across Wallacea. This project addresses three aims, which require addressing to overcome these challenges. Firstly, we will employ traditional visual observation techniques for reef corals, macro-invertebrates and fishes to determine how ecological networks differ between largely unimpacted, sedimented or reduced water quality, and fished sites. Ecological networks will be quantified based on field data using novel/cutting edge ecological modelling approaches and network theory. This aim focuses on easily observable non-cryptic taxa initially, and will form the basis of our comparative assessment of eDNA which has great potential but remains unvalidated in coral reef systems. Our second aim will validate eDNA's utility in describing reef biodiversity dynamics and test for the first time how networks constructed from eDNA compare to those from ecological surveys. Outcomes will provide unique insights and the potential for a step change in reef monitoring approaches by expanding opportunities to intensify spatial and temporal sampling, alongside providing confidence limits associated with ecological networks and their metrics that have been constructed using these novel eDNA data. Finally, having assessed the application of eDNA techniques, we plan to map the coral reef biodiversity of Wallacea with extensive eDNA sampling from remote regions. We will expand eDNA sampling to 10 further sites within Wallacea to provide novel data at unprecedented spatial and ecological complexity scales, enabling us to model and predict change in response to anthropogenic pressures at scales most relevant to Indonesian marine spatial planning. Despite high functional redundancy in the mega-diverse coral reef ecosystems, the loss of species will shift community composition and functionality with wide-ranging ecological, social and economic implications. For conservation efforts in complex systems where cryptic species are under-sampled but play important functional roles, there is a real-world need to know true biodiversity and network interactions. We will develop and test novel approaches to tackle this challenge to inform sustainable development in the face of the coral reef crisis. The response dynamics in ecological networks inform community robustness and this information is key to management decision making.