New study questions whether Mexico's celebration of wild orchids can be ecologically sustainable
We often associate holidays with specific plants. Christmas decorations in North America abound with poinsettias and mistletoe. In households across Japan, the New Year is symbolized in displays of pine, plum and bamboo. The colors, smells, arrangements and tastes of symbolic plants mark these rituals forever in our sensory memories.
For many Mexicans, cultural and religious holidays - from Holy Week to Christmas to Day of the Dead - are associated with colorful and fragrant flowers. These include, among others, a dizzying range of orchid species that are enjoyed in different ways and by diverse sectors of society: from personal adornment in rural community processions, to elaborate church decorations in bustling towns, to cut flowers that brighten up household tables in the megalopolis of Mexico City. Despite their diversity, these orchids all have one thing in common: they are wild-harvested. Can this celebration of wild orchids be ecologically sustainable?
Wild-harvested Euchile karwinskii orchid flowers (yellow), adorn a crucifix during Holy Week.
Photo Credit: Demetria Mondragón.
Hundreds of wild-harvested Laelia speciosa orchid flowers (purple) adorn church decorations during Corpus Christi.
Photo Credit: Cecila Zamora Sanchez
We recently carried out a study to try to answer this question. First, we determined what is being harvested: which species, where, when and in what volumes. We worked with existing information sources, including market studies and records of government raids of markets. The vast majority of wild orchid sales in Mexico are illegal, since harvest permits tend to be too difficult for most vendors to obtain. We found hundreds (333) of wild-harvested taxa sold in local markets across the country- a third of all Mexico's epiphytic orchids! However, less than 4% of the total species were traded in high volumes, and all of these had showy flowers that bloomed during holiday seasons. They also all had pseudobulbs - a point that becomes important when we think about sustainability. In fact, while whole plants were found for sale in all markets, the majority of sales were of pseudobulbs with flowers.
Wild-harvested orchids sold in Mexican markets alongside other flowers.
Photo Credits: Cecila Zamora Sanchez and Daniela Dutra-Elliott
Next, we asked if these patterns of harvest might be ecologically sustainable. To do this, we carried out a global analysis of existing studies on the population dynamics of epiphytic orchids. Despite the blooming harvest of wild orchids across the globe, we found a dismal lack of studies on species in trade. Still we pulled together studies of populations of 19 species with differing life histories. We found that many of the studied orchid populations were decreasing without any harvest, mostly due to habitat degradation. Using a variety of modeling techniques, we then identified the potential impacts of different levels and types of harvest on the ability of populations to persist over the long-term.
Our results suggest that for most epiphytic orchids, whole-plant harvest - as is practiced for horticultural trade - is not likely to be ecologically sustainable, even if harvest occurs at the lowest levels. However, we did however find some scope for the sustainable harvest of pseudobulbs and/or flowers, if these are harvested from a portion of the plants in a population. Removal of one of two of the largest flowering pseudobulbs leaves the individual alive, with the ability to regrow pseudobulbs of reproductive size. While the specifics will vary across species and locations and requires more research - especially in collaboration with local harvesters - our results suggest a way forward for sustainable use. This is encouraging news not only in Mexico, but globally, where the harvest of many species of wild orchids used for cut flowers, medicine or decorations can involve removal of only inflorescences and/or pseudobulbs. In areas of degraded habitat and/or declining populations, this could involve replanting.
Laelia speciosa growing in a forest population. Photo Credit: Leonel Lopez-Toledo
Euchile karwinskii replanted in a home-garden after being wild- harvested and used for decorations.
Photo Credit: Julia Douglas
In terms of conservation of Mexico's orchids, our results led us to suggest a multipronged approach that includes selective monitoring of those heavily harvested species; enforcement approaches that focus on whole-plant harvest/sales; and the legalization and promotion of community-based wild-harvest of pseudobulbs or inflorescences from forests and homegardens. Clearly this won't solve all problems, nor will it do so overnight - but it can take us a step in the right direction: that is, a step towards maintaining wild orchid populations while supporting those traditions that connect us so intimately to them.