Regeneración Agroecológica: ¿Por qué?

Diego Griffon

An eco-evolutionary theory of host-associated microbiomes 

Araujo et al., 2026

Host-associated microbiomes often display host specificity and heritability, yet the evolutionary processes under which such structured communities first emerge are still unclear. In particular, the conditions by which intergenerational (i.e., vertical) transmission of microbes can evolve and generate host-specific microbiomes are still unresolved. Here, we present an eco-evolutionary theory of microbiome assembly under minimal assumptions of microbial dynamics (i.e., neutrally driven by environmental fluctuations) and host control. We consider the adaptive evolution of microbial and host traits, including microbiome size and vertical transmission. We show that environmental fluctuations can generate enough among-host microbial variation to enable host-level selection favoring beneficial microbiome configurations. Vertical transmission can then evolve and, even when weak, allow microbiome specificity to be inherited and amplified across generations despite continuous influx from the external environment. Selection is most effective at intermediate levels of environmental fluctuation and host lifespan, revealing fundamental trade-offs between stochastic assembly, inheritance, and dispersal of microbes. The resulting microbiomes are dense, host-specific, and heritable, yet retain high intraspecific variability and lack strict phylosymbiosis. Simulated patterns of microbial dominance, diversity, and host–microbiome dissimilarity closely match those observed in nature, as evidenced using marine sponge microbiomes. Our results provide a mechanistic theory for the early evolution of host-associated microbiomes, showing that beneficial and species-specific communities can arise through selection and inheritance prior to the evolution of dedicated host-control mechanisms.

https://www.pnas.org/doi/10.1073/pnas.2612550123

Higher and more stable biological control of multiple herbivore species in diversified strip cropping systems 

Bolletta et al., 2026

1. Context: Agricultural intensification has simplified agroecosystems, reduced biodiversity and weakened natural pest control. Effective biological control requires reliable, long-term control of multiple herbivores. While studies investigated biological control in diversified cropping systems, there is little information as to what extent pest suppression is sustained throughout the growing season and whether it provides satisfactory control of several herbivores.
2. Objectives: Here we assessed how increasing crop diversity and an ‘attract-and-reward’ (A&R) strategy influence the effectiveness and temporal stability of biological control.
3. Methods: We compared predation, parasitism of eggs and caterpillars in a cabbage system with four levels of crop diversity: cabbage monoculture, cabbage-oat strip cropping, strip cropping with six crops and an A&R system in which a strip cropping system was enhanced by inclusion of a parasitoid-attractive cabbage cultivar and nectar-providing buckwheat. Experiments were conducted at two organically-managed farms in the Netherlands in 2023 and 2024. Additionally, a full-factorial experiment was conducted in 2023 at one location to assess the effects of the A&R components. Temporal stability was quantified as the coefficient of variation and the proportion of sampling weeks in which each treatment exceeded the mean biological control level.
4. Results: Across locations and years, strip cropping enhanced parasitism rates of Pieris brassicae and Plutella xylostella compared with monocultures. Pieris brassicae parasitism increased from 28% in monocultures to 58% in strip cropping systems, while P. xylostella parasitism rose from 10% to 25%–30%. Parasitism of Mamestra brassicae eggs by Trichogramma spp. reached up to 30% in the strip cropping system with six crops, compared with 1% in monocultures. A&R provided no improvement beyond standard strip cropping. Monocultures showed the highest coefficient of variation and exceeded the site-year mean in only 13% of weeks, compared to more than 60% in strip crop systems.
5. Synthesis and application: Our results highlight that strip cropping can enhance and stabilize biological control. Even simple two-crop designs provide clear benefits over monocultures, while increasing crop diversity to six crops offers additional advantages. Because the temporal stability of biological control increases with crop diversity, designing strip cropping systems with more crops can help maintain consistent and resilient pest regulation throughout the growing season.

https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2664.70381

Predator decision-making shapes the dynamics and stability of mimicry systems 

Sun and Ke, 2026

1. Mimicry is an anti-predator strategy in which prey species (the mimic) resemble an unprofitable species (the model) to deceive predators. Despite theoretical expectations for perfect mimicry, imperfect mimicry, where the mimic resembles its model imperfectly, is widespread in nature.
2. To understand how imperfect mimicry can persist ecologically, we studied the effect of different predator recognition processes on the dynamics and stability of various mimicry systems. Specifically, we extended a dynamical model that integrates optimal foraging and signal detection theories by introducing a novel abundance-dependent recognition mechanism, where predators' perception of the similarity between mimic and model is influenced by the relative abundance of prey types.
3. We demonstrate that intermediate similarity promotes stable community dynamics and increases mimic abundance in single Batesian mimicry systems. Moreover, abundance-dependent recognition leads predators to reduce attack on mimics with low morphological similarity, further contributing to system stability.
4. Extending the framework to a multi-mimicry system, we find that Batesian and Müllerian mimics have contrasting effects: Intermediate Batesian similarity continues to stabilize the system, while high Müllerian similarity provides additional protection and can offset destabilization caused by highly similar Batesian mimics.
5. Our study offers a novel explanation for the prevalence of imperfect mimicry in nature and highlights how recognition processes shape the ecological stability of mimicry systems.

https://besjournals.onlinelibrary.wiley.com/doi/abs/10.1111/1365-2656.70319