Background:

Flowers are expensive reproductive elements that have cost/benefit balances in their characters. The diversity of the floral structures has been attributed to biotic factors such as the interactions with their floral visitors and abiotic factors such as the characteristics of the environment.

Question:

Is there a relationship between the floral morphology of M. geometrizans and the vegetation type? Is the community of arthropod floral visitors associated with floral morphology and/or the vegetation type? Will the floral morphology and the community of arthropod floral visitors be associated with the disturbance level of the environment?

Studied species:

Myrtillocactus geometrizans (Mart. ex Pfeiff.) Console

Study site and dates:

Tropical deciduous forest and xerophilous scrub in the Tehuacán-Cuicatlán Biosphere Reserve, Puebla, and in the Barranca de Metztitlán Biosphere Reserve, Hidalgo, Mexico. March 2017.

Methods:

At the four sites (two days per site), during the flowering peak of M. geometrizans, the disturbance index was calculated, 30 flowers (N = 120) and the arthropods floral visitors were collected. Floral morphology and arthropods were determined.

Results:

Barranca de Metztitlán sites showed the highest disturbance index, the smallest flowers, and the highest production of floral structures. Flower visitors were more abundant in xerophilous scrubs, particularly in the most disturbed site, where the most relevant functional group was the pollinators.

Conclusions:

Significant differences were found in the floral morphology of M. geometrizans related to vegetation types and geographic location. A trade-off between the size and production of floral characters was reported.