Species–habitat networks: A tool to improve landscape management for conservation

Abstract

Land‐use change is reshaping terrestrial ecosystems world‐wide and is recognized as a key driver of biodiversity loss with negative consequences on ecosystem functioning. Understanding how species use resources across landscapes is essential for the design of effective management strategies. Despite recent advances in network ecology, there is still a gap between theory and applied ecological science, and we lack the information to manage entire landscapes to maximize biodiversity conservation and ecosystem service delivery. While several pioneering approaches have tried to link ecological networks and conservation science, applied ecologists still struggle to incorporate these models into research due to their inherent complexity. We propose the application of bipartite networks principles to create species–habitat networks. This approach explicitly links multiple species and habitat resources, provides tools to estimate the importance of particular species or specific habitat in a given landscape, and quantifies emerging properties of entire habitat networks. Most existing metrics used to study properties of bipartite ecological networks can easily be adapted to investigate species–habitat relationships. The tool use is relatively simple and does not require advanced computational expertise. Synthesis and applications. One of the biggest challenges in applied ecology is managing multiple habitats for the effective conservation of multiple species. One key advantage of this proposed approach is that the scale of the derived ecological information could match the scale of landscape management interventions. The versatility, visualization power and ease of interpretation of these networks will enable application of the species–habitat network concept to a wide array of real‐world problems, such as multispecies conservation, habitat restoration, ecosystem services management or invasion ecology. In particular, species–habitat networks could be applied to identify optimal landscape compositions and configurations to design effective interventions at the landscape scale. This approach also enables the detection of emerging network properties that could also be used to test the effects of large‐scale drivers of global change upon ecosystem structure and stability.

Species–habitat networks elucidate landscape effects on habitat specialisation of natural enemies and pollinators

“…Further advances in network ecology with the development of metrics capable of quantifying the level of specialisation of the involved organisms (e.g. Poisot et al ., 2012; Delmas et al ., 2019) now allow to fully describe the complexity of species–habitat networks (Marini et al ., 2019). The main advantage of this approach is that species–habitat associations can be envisioned as bipartite networks between species and habitat patches, which can then be analysed with the well‐established suit of specialisation metrics at the species and network levels (Dormann et al ., 2008).…”

Evaluating the taxa that provide shared pollination services across multiple crops and regions

“…Although a mix of wild and managed pollinating taxa is a prudent strategy, we still know relatively little about (i) the identity of wild pollinators that visit multiple co-flowering or sequentially flowering crops across a number of growing regions and (ii) the level of specialisation of pollinator taxa on crops across different habitats. Quantification of the connections between plants and pollinators 36–38 , species and habitats 39 , and crops and pollinators 28 is urgently required in order to devise strategies that support the in-situ management of local, wild pollinator taxa across multiple crops and regions. This would provide a focus for management efforts on local, wild pollinator taxa that already exist in a given landscape, to support or augment managed honey bee services, without importing new exotic taxa and their associated pests, parasites and disease 1–3,12,40–42 .…”

Network modularity influences plant reproduction in a mosaic tropical agroecosystem

“…Understanding the causes and consequences of modularity is important as it can have a positive effect on stability and ecosystem function [44,58,59], especially in human-dominated landscapes and disturbed systems [60]. Although this modularity–stability relationship is generally considered in terms of mutualistic plant–pollinator networks [44], future work should aim to determine how this translates to pollinator–habitat networks [22]. The landscape network in this study was significantly modular compared with a random network.…”

“…More recently, the utility of traditional network approaches to solve conservation and applied ecology problems has been demonstrated [22,26,27]. Greater understanding of how the structure of interaction networks influences ecosystem function, as well as how landscape management influences network structure, is essential to inform decisions that sustain biodiversity and ecosystem services in managed landscapes [22]. Historically, analyses of network structure have largely concentrated on global properties, such as degree distribution.…”