Can Botanists Rescue the Endangered Orchids of Malaysia?

A study by Besi and colleagues sheds light on the worrying threat to orchid species diversity posed by human activity (anthropogenic) and natural disasters (naturogenic). Published in The Botanical Review, the authors call for urgent conservation initiatives before we lose the irreplaceable diversity of these beautiful and complex plants. The scientists point out that orchids are not just beautiful; they are indicators of a healthy ecosystem with their intricate pollinator relationships and niche adaptations. Their loss can signal a decline in ecosystem health and resilience.

Besi and colleagues highlight the need for ongoing ‘diversity, taxonomy, and conservation’ studies of orchids, stressing the importance of more accurate estimates of orchid diversity using combined methods of morphology, anatomy, and molecular genetics. The study reveals that changes in microclimate conditions and habitat structures are essential determinants for both epiphytic (those that grow on other plants) and terrestrial orchid assemblages after disturbances. It also underscores the importance of incorporating varying forest types and management regimes into biodiversity assessments, providing a broader view of the impact of forest and ecological disturbances on orchid communities.

Orchids, belonging to the family Orchidaceae, have the most impressive range of flower variation among monocotyledonous plants. Malaysia is considered a ‘hot spot’ of orchid diversity, with around 1,000 species recorded in Peninsular Malaysia and up to 3,000 spanning Sabah and Sarawak. These ecological riches, however, are under unprecedented threat due to deforestation, notably in Sarawak and Sabah, where logging has significantly impacted more than 80% of forests.

A systematic approach was adopted to assess the diversity of orchids in various environments. These included undisturbed forests with high orchid diversity, secondary forests regenerating after clear-cutting with lower species abundance, and logged forests with drastic microclimate changes. Unsurprisingly, the study demonstrated that logged forests generally had lower orchid density than disturbed secondary forests. The most shade-adapted epiphytes, which are susceptible to dryness, are often replaced by sun-adapted ones. The scientists found correlations between species density and crown closure, indicating a strong influence of microclimate on patterns of diversity and floristic composition.

The sobering results confirmed that anthropogenic and naturogenic threats impose unprecedented strains on orchid communities. These pressures encourage harmful changes in microclimatic conditions and habitat structures crucial for orchid survival. To make matters worse, excessive logging exposes orchids to intense heat and dryness, leading to a slow but steady death of these precious plants. The study also shed light on the critical association between the rare and endangered orchids and their symbiotic microbial partners that have largely been overlooked until now.

But there’s a glimmer of hope. Besi and colleagues highlighted opportunities involving rescuing orchids from logging sites. They write:

Rescuing orchids from logging sites gives the opportunity to collect all orchids especially those from the tree canopy that leads to discovery of many new and cryptic species. Cryptic species, product of rapid evolutionary radiations within a single genus, can form suites of morphologically similar taxa or species complexes that are indistinguishable both in the field and the herbarium (Elliott & Davies, 2014).

Besi et al. 2023

Understanding of these ‘cryptic species’ has been significantly enhanced by drawing on tools from DNA barcoding and floral anatomy, leading to exciting discoveries and a clearer picture of the taxonomic diversity within the family Orchidaceae. The research closes with a stark warning and a passionate plea for large-scale conservation initiatives to preserve orchid species. 

For threatened species, whose trade is regulated by the CITES, correct identification is crucial for the enforcement of the regulations and future conservation of the species. As well the application of IUCN Red List Criteria at Regional and National levels is much recommended to re-evaluate the current orchid diversity status in Malaysia.

Besi et al. 2023

READ THE ARTICLE
Besi, E.E., Mustafa, M., Yong, C.S.Y. and Go, R. (2023) “Deforestation impacts on diversity of orchids with inference on the conservation initiatives: Malaysia case study, The Botanical Review. Available at: https://doi.org/10.1007/s12229-023-09292-y.