ALMaSS is a landscape-scale simulation system for investigating the effects of changes in landscape structure and management on animal populations and ecosystem services in European agricultural landscapes.
As an open-source, open-science platform hosted on GitLab since 2010, ALMaSS enables researchers, regulators, and policymakers worldwide to assess the impacts of agricultural policies, pesticide use, and land management decisions on biodiversity.
ALMaSS employs agent-based modelling, representing individual animals as autonomous agents that move, forage, breed, and die within virtual landscapes that mirror real-world conditions.
What distinguishes ALMaSS from other ecological models is its use of dynamic rather than static landscapes—a comprehensive simulation environment where:
This level of detail enables predictions about how individual-level responses to environmental conditions scale up to population-level impacts, a critical capability for regulatory risk assessment and conservation planning.
Initially developed for Denmark starting in 1998, ALMaSS now operates across 12 European countries including Denmark, Germany, Sweden, Poland, Italy, Belgium, UK, Netherlands, and France. The expanding geographic coverage is supported by national research funding and EU Horizon projects.
The system includes validated models for diverse taxonomic groups:
ALMaSS currently supports cutting-edge research and regulatory initiatives:
Environmental Risk Assessment The ApisRAM honey bee model, developed within the ALMaSS framework, is being implemented for EFSA regulatory use in pesticide risk assessment. The system provides the landscape and pesticide fate modelling underpinning next-generation risk assessment approaches that consider multiple stressors, landscape context, and population-level effects.
PollinERA Project (2024-2027) This Horizon Europe initiative uses ALMaSS to develop systems-based environmental risk assessment for pollinators, moving beyond single-species, single-pesticide approaches to ecologically realistic assessments considering landscape dynamics, multiple stressors, and diverse pollinator groups.
Ecosystem Services ALMaSS models are applied to evaluate pollination services, biological pest control, and trade-offs between agricultural production and biodiversity conservation under different farming systems and policy scenarios.
Recent developments include:
ALMaSS is the principal tool developed and applied by the Social-Ecological Systems Simulation Centre (SESS) at the Department of Agroecology, Aarhus University, Denmark.
SESS collaborates with European and national institutions, including:
As well as research organisations, agroindustry, and NGOs throughout Europe. An overview of major SESS collaborators is found here.
Comprehensive model documentation is available through the ODdox system, a format specifically designed for navigating complex agent-based models. Formal model descriptions for individual species are published in the Food and Ecological Systems Modelling Journal (FESMJ), ensuring transparency and reproducibility.
Developments are available via our ALMaSS GitLab project page.
ALMaSS related publications are displayed in the ALMaSS Outputs Collection in the RIO Journal.
The Aarhus University ALMaSS Pure site showcases major projects related to ALMaSS, as well as all associated publications.
