On the distribution and conservation of Sievekingia hirtzii Waldvogel (Orchidaceae, Stanhopeinae): first records from Colombia

. We newly report two populations of the orchid Sievekingia hirtzii in the Andean–Amazonian foothills of Caquetá, Colombia. Following the B criterion of the International Union for the Conservation of Nature, we propose the categorization of this species as Endangered, due to its small Area of Occupancy and Extent of Occurrence, the limited number of populations, and habitat fragmentation and degradation caused by the expansion of agriculture. Additionally, we propose actions for in situ and ex situ conservation of this orchid, including habitat protection and cultivation in botanical gardens.


Introduction
The Orchidaceae Juss.are epiphytic, lithophyte, terrestrial, and mycoheterotrophic plants and have a diversity of near 25,000 species worldwide (Chase et al. 2015;Phillips et al. 2020;Pérez-Escobar et al. 2022).Colombia harbors nearly 20% of this diversity, mainly in the Andes (Betancur et al. 2015).The tribe Stanhopeinae Benth.(subfamily Epidendroideae Kostel.) has Neotropical distribution and encompasses 21 genera, all of them producing short-duration flowers that emit a scent to attract euglosine male bees; when these bees enter upside down flowers, the pollinarium is attached to the trochanter of their legs (Dressler 1976;Rehman et al. 2016).The genera of the tribe Stanhopeinae-Cirrhaea Lindl., Soterosanthus F. Lehm.ex Jenny, Sievekingia Rchb.f., and Trevoria F. Lehm.-have a hook-shaped viscidium adapted to stick the pollinarium in the legs of the bees.In Sievekingia the stipe twists inward under the body of the pollinator (Dressler 1976;Whitten et al. 2000;Gerlach 2003).
Sievekingia is characterized by small to mediumsized plants with rounded to pyriform, sulcated pseudobulbs, one terminal leaf, and compact inflorescences with numerous flowers (Dressler 1976;Villegas 2007).The flowers of this genus are less specialized; the shallow pouch behind the callus contains the osmophores, and the labellum may be distinguished from the petals, but is difficult to differentiate the hypochile, mesochile, and epichile (Curry et al. 1991;Rehman et al. 2016).This genus is composed of 14 species distributed in Central and South America, six of them known to occur in Colombia: S. colombiana Garay, S. cristata Garay, S. fillifera Dressler, S. herklotziana Jenny, S. reichenbachiana Rolfe, and S. suavis Rchb.f..The first three species occur in the Andes at 600-1200 m a.s.l. and the last two species in the Chocó bioregion to elevations of 500 m (Betancur et al. 2015;Bernal et al. 2019, POWO 2023).
Extending from Amazonia to the Andes, the department of Caquetá harbours more than 9% (418 species from 98 genera) of the Orchidaceae of Colombia (Arias et al. 2023).Unfortunately, Caquetá is one of the departments with uncontrolled deforestation, mainly causes being illegal wood extraction and the expansion of the agricultural frontier for livestock and illicit crops (Myers et al. 2000;Armenteras et al. 2007;Malhi et al. 2008).This has led to the loss of more than 30% of the forest cover, which is habitat for many species, and the decline of biodiversity (Köster et al. 2009(Köster et al. , 2011;;Hoffmann et al. 2018;Sierra et al. 2022).
Local and national policies to ensure biodiversity conservation have a low impact in Caquetá.In consequence, deforestation, illegal extraction, and the trade of orchids, plus the lack of knowledge about species' diversity, are threats to the survival of wild orchid populations.To help improve knowledge of the orchid diversity in Colombia, we report the first records of S. hirtzii from Colombia, assess the risk of extinction of this species using IUCN criteria, and propose actions to protect and conserve this species.

Methods
We found two populations of Sievekingia hirtzii in the department of Caquetá, in the Colombian Amazon.One population is in Alto Fragua Indi-Wasi National Natural Park (municipality of Belén de Los Andaquíes; Fig. 1) and was found during in an expedition of the project "Taxonomy diversity of epiphytes in the Andean-Amazonian Foothills of the Caquetá department".The other population was found in the Caraño river basin (rural Florencia; Fig. 1), in an expedition supported by the project "Strategy for knowledge, study, and conservation of the orchid flora of the Andean-Amazonian foothills of Caquetá department".We compared individuals from these populations to the description of the species by Waldvogel (1977).We searched for geographical information in the Global Biodiversity Information Facility (GBIF), Distributed Information System for Biological Collections (SpeciesLink), Tropicos.org,and Plants of Colombia Catalogue.In addition, we searched online records in the databases of the COAH and COL herbaria (acronyms according to Thiers 2023), and we used Google Scholar to scientific literature on S. hirtzii.
Our voucher specimens were deposited the CUVC herbarium (acronym according to Thiers 2023).We used the location of the populations and the B criterion of the International Union for Conservation of Nature categories and criteria (IUCN 2022) to risk of extinction for S. hirtzii.Forest-cover loss data from 2001 to 2022 (Hansen et al. 2013) were used in R (R Core Team 2022) to estimate deforestation in the Extent of Occurrence (EOO) of the species; this was used as a proxy for habitat loss.The map (Fig. 1) and bar plot (Fig. 3) were produced using RStudio (RStudio Team 2022).

Results
Sievekingia hirtzii Waldvogel.Die Orchidee 28: 5-7 (Waldvogel 1977) Figure 2 Previously known records (Fig. 1).Conservation status.We categorized S. hirtzii as globally Endangered under criteria B1 + B2ab(i, iii) because there are four populations, the AOO is only 16 km 2 , and there is a continuing loss and degradation of habitat that has led to the loss of 12.6% (2,118 km 2 ) of the forest cover in the EOO (16,699 km 2 ).

Conservation strategies.
We propose five strategies that may help in the conservation of S. hirtzii populations and their habitat.All strategies are from literature dealing with the conservation of epiphytic orchids. 1) In situ conservation-preserve species' habitat; consider life history traits; follow development of populations and their ecological relationships with mycorrhizal fungi, pollinators, dispersers, and predators (Orejuela-Gartner 2012; Zhou et al. 2021).
2) Ex situ conservation-cultivate plants in botanical gardens and institutions dedicated to plant conservation; collect and cryopreserve germplasm; conserve and reproduce associated mycorrhizal fungi (Seaton et al. 2010;Merritt et al. 2014;Zhou et al. 2021).
3) Sustainable use-implement through programs to develop trade of cultivated specimens obtained from vegetative and in vitro reproduction; implement orchid ecotourism; secure equitable distribution of social, economic, and environmental benefits of use (Orejuela-Gartner 2012;Fay 2018;Zhou et al. 2021;Longchar and Deb 2022;Mutum et al. 2023).
4) Research-study pollination biology and reproductive biology of species; identify pollinators, dispersers, and predators; determine the risk of extinction of the species; establish conservation priorities and policies (Orejuela-Gartner 2012; Wraith et al. 2020;Zhou et al. 2021) 5) Education-involve people in rural and urban areas and employees of institutions in conservation and surveillance of natural resource exploitation; expand knowledge on the importance of conservation of orchids, as well as on biology and ecology of orchid species; develop and understanding of the relationship between socio-economic development and orchid conservation (Swarts and Dixon 2009;Orejuela-Gartner 2012;Gale et al. 2018).

Discussion
Caquetá department in Colombia harbours incredible biodiversity, mainly due to its location at the confluence of the Amazonia and Andes biomes (Gentry 1992;Bush et al. 2008).This region is classified into three altitudinal subregions: Amazonian lowlands below 250 m, Andean-Amazonian foothills at 250-800 m, and Andean Amazonia above 800 m (Hoekstra et al. 2010).Consequently, there are many niches for orchids, especially in the Andean region, which is considered the most species-rich in Colombia (Betancur et al. 2015).Our new records of Sievekingia hirtzii in two different areas in the Caquetá foothills indicates that there is a need for more botanical expeditions to explore and identify the whole orchid diversity of this department.Our assessment of S. hirtzii as Endangered highlights the threats that this species faces, mainly the loss of the habitat in the cloud forests as a consequence of deforestation and agricultural expansion (Viña and Cavelier 1999;Dixon and Phillips 2015;Hoffmann et al. 2018;Sierra et al. 2022).The loss of phorophytes is a driver of habitat loss for this species and numerous other orchid species (Califa and Bravo 2020;Montibeller-Silva et al. 2020).One S. hirtzii population that we found was in Indi-Wasi National Natural Park, a protected area of 72,600 ha.This park is in eastern Caquetá department, on the slopes of the Andes and a portion of Andean-Amazonian foothills (Rebolledo 2019).The park implies that the habitat of this population is protected, but the other population, in the Caraño river basin, is in a forest fragment of less than 1 ha, is threatened by the expansion of surrounding pastures (Fig. 3).Other orchid species from this area, like Epidendrum porphyreonocturnum Hágsater & R. Jiménez, E. whittenii Hágsater & Dodson, and the recently described Masdevallia leonor-baeziana Os.Perd., Edwin Trujillo & Karremans, were categorized as at risk of extinction because of deforestation, habitat fragmentation, and an expanding agricultural frontier (Perdomo et al. 2020(Perdomo et al. , 2023)).
Although the illegal commercialization of orchids does not affect the area of occurrence of S. hirtzii, we point out the need for strategies to protect this species from this largely unnoticed threat, which is currently categorized as an urgent, global priority for orchid conservation (Cooney et al. 2017;Margulies et al. 2019).We highlight the lack of conservation policies and efforts to conserve orchids in the Caraño river basin and the scarcity of government presence in environmental control and protection.Although S. hirtzii is in Appendix II of the CITES (https://www.speciesplus.net/),the restriction for the trade needs to be declared and applied by local authorities.Finally, another threat to the orchid flora is climate change, which has now been said to be the most critical threat to all the biodiversity on Earth (Dixon and Phillips 2015).
Both populations require monitoring for growth, reproduction, and ecological interactions to ensure their survival (Orejuela-Gartner 2012; Zhou et al. 2021).Ex situ conservation actions, like inclusion of specimens in botanical gardens, reproduction by institutions dedicated to plant conservation, and preservation of germplasm and pollen, are required to secure genetic material for future research (Seaton et al. 2010;Merritt et al. 2014).In vitro propagation should be done to obtain vegetative materials of S. hirtzii to reproduce and cultivate in nursery gardens (Longchar and Deb 2022; Mutum et al. 2023).The beautiful, colorful flowers of this species, characteristics sought after in orchids, suggest potential trade in this species.
Although knowledge of the diversity of Orchidaceae in Colombia has improved in recent decades, biology, ecology, and risk of extinction remain unassessed for most species (Orejuela-Gartner 2012; Alba et al. 2021).For S. hirtzii, no studies have been developed, and there is only its original description (Waldvogel 1977) and a host-epiphyte analysis (Paredes et al. 2021).Thus, additional research is needed to improve our understanding of this species and better develop conservation strategies.Finally, environmental education on this species, including its biology, ecology, risk of extinction, and trade restriction under CITES, is needed to highlight the importance of this and other orchid species to the ecosystem and socio-economic development of the region (Orejuela-Gartner 2012; Dixon and Phillips 2015;Gale et al. 2018).Education will lead to the valuation of orchids and their habitat from a sustainable perspective, where the environment and plants are at the center of local socio-economic development.

Figure 1 .
Figure 1.Populations of Sievekingia hirtzii recorded in Ecuador (black points) and the new records from Colombia (red points).