Project

Back to overview

The Influence of land-use and elevation gradients on network structure of Ecuadorian hummingbird-plant interactions

English title The Influence of land-use and elevation gradients on network structure of Ecuadorian hummingbird-plant interactions
Applicant Graham Catherine
Number 173342
Funding scheme Project funding
Research institution Biodiversität und Naturschutzbiologie Eidg. Forschungsanstalt für Wald, Schnee und Landschaft WSL
Institution of higher education Swiss Federal Institute for Forest, Snow and Landscape Research - WSL
Main discipline Ecology
Start/End 01.08.2017 - 31.07.2022
Approved amount 680'795.00
Show all

Keywords (6)

Ecuador; interaction beta-diversity; beta-diversity; hummingbird-plant interactions; traits; network ecology

Lay Summary (German)

Lead
Prof. Dr. Catherine Graham
Lay summary

Die Wälder der Anden sind wegen ihrer außerordentlich hohen Biodiversität und ihrer Ökosytemleistungen von globaler Bedeutung. Ein Beispiel für diese große Artenvielfalt ist die Lebensgemeinschaft der Kolibris und ihrer Nahrungspflanzen: Auf kleinstem Raum leben etwa 26 Kolibri-Arten und 70 Gefäßpflanzen. Die Ursachen für die hohe Biodiversität der tropischen Bergwälder sind jedoch kaum erforscht. Eine wichtige Hypothese, die diese grosse Artenvielfalt erklärt, ist resource partitioning. Sie besagt, dass jede Art eine eigene Palette von Ressourcen ausbeutet, was die Ressourcen-Konkurrenz zwischen Arten verringert und damit das Zusammenleben zahlreicher Arten ermöglicht. Bisher konnte diese Hypothese allerdings kaum getestet werden, denn ein solcher Test setzt Daten zur Ressourcennutzung diverser Arten unterschiedlicher Standorte voraus- Informationen, die in tropischen Ökosystemen häufig fehlen. Im vorliegenden Projekt sollen Daten zu Interaktionen zwischen Kolibris und Pflanzen entlang zweier Umweltgradienten gesammelt werden, und zwar entlang eines Höhen- (800-3400 m. ü. M.) und eines Störungsgradienten, der von den Urwäldern bis zu den Weiden der ecuadorianischen Anden reicht. Ausdrücklich soll dabei nicht nur der Wechsel der Kolibri- und Pflanzenvielfalt entlang der Gradienten erforscht werden, sondern hauptsächlich Veränderungen in der Interaktion zwischen den beiden Organismengruppen. Die allgemeinen Ziele der Studie sind i) mit einem einzigartigen, später allgemein zugänglichen Datensatz bestehende Wissenslücken über Tier-Pflanzen-Interaktionen zu füllen; ii) die Hypothese zu testen, ob resource partitioning zu einer höheren Biodiversität führt; iii) herauszufinden, wie resource partitioning entlang von Höhen- und Landnutzungsgradienten variiert;  iv) zu erforschen, ob die durch Landnutzung und Klimaunterschiede verursachten phänologischen Veränderungen Auswirkungen auf Artenvielfalt und Interaktion der beiden Gruppen haben.  

Direct link to Lay Summary Last update: 04.07.2017

Lay Summary (English)

Lead
Prof. Dr. Catherine Graham
Lay summary

Andean forests are of global importance due to their outstanding biodiversity and the ecosystems services they provide.  For example, diversity of hummingbirds and plants is extremely high in the Andes with co-occurrence of ~26 hummingbird species and ~70  vascular food plants in a small area. Scientists do not yet understand exactly what causes elevated species richness in tropical mountains.  However, one of the main hypotheses explaining this diversity is resource partitioning where each species uses a different set of resources which reduces resource competition and thus permits many species to co-occur.  This hypotheses has been difficult to test because it requires data on resource use from multiple sites and species; information often lacking in diverse tropical systems.  In this project we will gather data on hummingbird-plant interactions across two gradients: an elevation gradient from 800-3400 m and a disturbance gradient from pristine forests to pasture land in the Andes of Ecuador.  We will use this information to not only evaluate  how hummingbird and plant species richness varies across these gradient, but also how the interactions among these groups change.  Our overall aims are to (i) fill the existing data gap by gathering a unique dataset on plant-animal interactions which will be made available to the community; (ii) test our hypothesis that niche partitioning results in high diversity; (iii) evaluate how niche partitioning varies across elevation and land-use gradients as species composition of both hummingbirds and plants change; and (iv) evaluate how land-use and climate induced phenological changes might influence richness of each group as well as their interactions.

Direct link to Lay Summary Last update: 04.07.2017

Responsible applicant and co-applicants

Employees

Project partner

Collaboration

Group / person Country
Types of collaboration
Aves y Conservacion Ecuador (South America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
7th Frugivores and Seed Dispersal Symposium Talk given at a conference Rewilding defaunated Atlantic Forests with tortoises to restore lost seed dispersal functions 02.03.2020 Corbett, India Bello Carolina;
GfO Conference 2019 Talk given at a conference Two sides of the coin: different strategies for hummingbirds and plants 09.09.2019 Munster, Germany Graham Catherine; Bello Carolina;
Ekologie 2019 – 7th Conference of the Czech Society for Ecology Talk given at a conference Key note: Linking patterns and processes across scales: a case study with Neotropical hummingbirds 06.09.2019 Olomouci, Czech Republic Graham Catherine; Bello Carolina;
European Ornithological Union Conference Talk given at a conference Mechanisns influencing spatial and temporal variation in hummingbird-plant interactions (Plenary) 28.08.2019 Cluj-Napoca, Romania Graham Catherine;
International Biogeography Society Meeting Poster Plant-hummingbird interactions along gradients of elevation and deforestation in the tropical Andes of Ecuador 08.08.2019 Quito, Ecuador Graham Catherine; Guevara Esteban;
43rd New Phytologist Symposium Poster The 43rd New Phytologist Symposium, 'Interaction networks and trait evolution' 01.07.2019 Zurich, Switzerland Graham Catherine; Bello Carolina;
The 43rd New Phytologist Symposium, 'Interaction networks and trait evolution' Talk given at a conference Invited talk: Ecological strategies that govern plant-hummingbird interactions 01.07.2019 Zurich, Switzerland Graham Catherine;


Self-organised

Title Date Place
Seed dispersal in the anthropocene. 7th Frugivores and Seed Dispersal Symposium; Organized Symposium: "Two side of the coin. Defaunation and rewilding effects on frugivory and seed dispersal processes” 02.03.2020 Corbett, India

Associated projects

Number Title Start Funding scheme
199379 Experimental Network Ecology and Restoration (Exper-net) 01.02.2022 SPIRIT
197753 Macroecology in environmental space 01.11.2020 Project funding

Abstract

The impacts of climate and land-use change will increasingly affect biological diversity, species interactions, and ecosystem services. One key question is how the changes in species identity, composition, and abundance alter trophic interactions. Network ecology aims to quantify interactions of species in a given assemblage, but rarely addresses changes in interactions across time and space. These interactions, such as a pollinator visiting a given plant species, form the architecture of biodiversity, yet we lack a unifying theory of interaction beta-diversity. Parsing out the influence of climate, resources, and seasonality on interaction networks will bring additional biological realism to our models of community stability. Past work has largely focused on describing network patterns, rather than generating explicit predictions for the change in species interaction and composition across space. Post-hoc comparison among widely separate sites and an inability to gather sufficient data at needed temporal and spatial resolution have hampered our ability to draw general conclusions. Especially in diverse tropical systems, we have little idea on how interacting species co-vary across a landscape, and the mechanisms behind species turnover and network change. Filling this gap first requires detailed knowledge of how and why individual species groups vary independently across temporal and spatial gradients - i.e., by quantifying drivers of compositional and trait beta-diversity. We can then study the relative contribution of species turnover, nestedness and the formation of new interactions in contributing to changes in network structure across space. Our goals are to (1) evaluate patterns of species and functional beta-diversity of hummingbirds and their food plants across elevation and land-use gradients in the Ecuadorian Andes; (2) evaluate hummingbird-plant interactions at multiple sites along gradients to test theoretical network predictions; and (3) quantify how and why interaction beta-diversity (turnover in species interactions, including both change in species composition, and change in interacting partners) changes across elevation and land-use gradients. Addressing these aims will allow us to (i) fill the existing empirical data gap by gathering a unique dataset on plant-animal interactions which will be made available to the scientific community; (ii) test theory about network structure and the mechanisms responsible for high tropical diversity; (iii) test and develop the concept of interaction beta-diversity; (iv) evaluate how land-use and climate induced phenological changes might influence network-structure.The proposed research, although ambitious, is feasible because the methods have been tested in the field in smaller-scale studies and all sites are identified and permissions for working at these sites have been or can be readily obtained (both at local and national levels). Further, this proposal will benefit from on-going research collaboration with Ecuadorian scientists and students who will provide logistical support, be involved in data-collection, and participate in resulting publications.
-