HomeIngredientFlexible drought deciduousness in a neotropical understory herb

Flexible drought deciduousness in a neotropical understory herb

August 20, 2022

Am J Bot. 2022 Jul 21. doi: 10.1002/ajb2.16037. Online ahead of print.

ABSTRACT

PREMISE OF THE STUDY: Adaptive divergence across environmental gradients is a key driver of speciation. Precipitation seasonality gradients are common in the tropics, yet drought adaptation is nearly unexplored in neotropical understory herbs. We examine two recently diverged neotropical spiral gingers, one adapted to seasonal drought and one reliant on perennial water, to uncover the basis of drought adaptation.

METHODS: We combine ecophysiological trait measurements in the field and greenhouse with experimental and observational assessment of real-time drought response to determine how Costus villosissimus (Costaceae) differs from C. allenii to achieve drought adaptation.

KEY RESULTS: We find that drought-adapted C. villosissimus has several characteristics indicating flexible dehydration avoidance via semi-drought-deciduousness and a fast economic strategy. Although the two species do not differ in water use efficiency, C. villosissimus has a more rapid growth rate, lower leaf mass per area, lower stem density, higher leaf nitrogen, and a strong trend of greater light-saturated photosynthetic rates. These fast economic strategy traits align with both field-based observations and experimental dry-down results. When faced with drought, C. villosissimus displays facultative drought-deciduousness, losing lower leaves during the dry season and rapidly growing new leaves in the wet season.

CONCLUSIONS: We reveal a drought adaptation strategy that has not, to our knowledge, previously been documented in tropical herbs. This divergent drought adaptation evolved recently and is an important component of reproductive isolation between C. villosissimus and C. allenii, indicating that adaptive shifts to survive seasonal drought may be an underappreciated axis of neotropical understory plant diversification. This article is protected by copyright. All rights reserved.

PMID:35862815 | DOI:10.1002/ajb2.16037

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About The Author

Patrick Blanchard MD

Meet Dr. Blanchard Dr. Blanchard’s medical practice is an embodiment of Integrative health which brings conventional and complementary approaches together in a coordinated way. Conveniently located in sunny Florida and over the internet with ValiseMD’s secure HIPPA compliant telXmed servers. Since 1994, patients with a wide range of challenging medical problems have achieved optimum health using the best of natural medicine, judiciously combined with high-tech innovations. Breakthroughs are often achieved even after patients have consulted mainstream specialists and holistic practitioners. Dr. Blanchard is founder and CEO of ValiseMD, Inc. He is board certified in Family Medicine since 1994 and awarded Fellow of the American Academy of Family Physicians in 2001. He received the ‘Teacher of the Year’ award from the University of Kansas School of Medicine at completion of his residency in Family Medicine. He completed a fellowship at Wake Forest University in the field of vascular neurosonology. He holds a medical patent in the field of Gastroenterology. He holds an unrestricted license to practice medicine and surgery in Florida. He started his medical career as a Emergency Medical Technician, then as a Paramedic and later a Medical Doctor.