Does extraction of orchids affect their population structure? Evidence from populations of Laelia autumnalis (Orchidaceae)

• Published in: Forest ecology and management Vol. 480; p. 118667
• Main Authors: Emeterio-Lara, Aucencia, García-Franco, José G., Hernández-Apolinar, Mariana, Toledo-Hernández, Víctor H., Valencia-Díaz, Susana, Flores-Palacios, Alejandro
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.01.2021
• Subjects: Chronic anthropogenic disturbance; Non-timber forest product; Oak forest; Plant biomass; Reproduction tradeoff; Reproduction tradeoff; Oak forest; Chronic anthropogenic disturbance; Non-timber forest product; Plant biomass
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/j.foreco.2020.118667

•Although extraction is recognized as a threat for orchids, its effects are unknown.•Extraction increases the abundance of old plants but diminishes that of the young.•Plant sections extraction diminishes the biomass of the plants and their flowering.•Fallow periods are required in populations under extraction. Chronic anthropogenic disturbance caused by the extraction of plant sections or entire individuals from wild populations can modify the population structure of the plants. Population structure, plant biomass capital and reproductive probability were compared in five Laelia autumnalis populations under different extraction intensities. For each plant, the number of pseudobulbs was counted and the biomass of each pseudobulb estimated and its live/dead status recorded along with the presence of inflorescence remnants. The live biomass of each plant was related to its total number of pseudobulbs. In populations under greater levels of extraction, the plants accumulate less biomass as they become larger. In populations under lower extraction, there was a greater abundance of small plants (1–9 and 10–18 pseudobulbs). In contrast, populations under higher extraction presented a structure with a greater abundance of large individuals (>19 pseudobulbs). In all populations, the frequency of the remains of inflorescences increases with plant size. In contrast, the development of inflorescences in the study season decreased as the intensity of extraction increased. In conclusion, extraction of Laelia autumnalis plants causes them to accumulate less biomass and become less likely to develop inflorescences as they age, and ultimately modifies their population structure toward an abundance of large, old plants.