The effects of hurricanes on the stochastic population growth of the endemic epiphytic orchid Broughtonia cubensis living in Cuba

We carried out a posthurricane evaluation of Broughtonia cubensis (Lindl.) Cogn., an endemic Cuban epiphytic orchid, after Hurricane Ivan (2004). We studied the transient responses in the stochastic dynamics of the species at three different sites over 13 successive years (2006–2019), monitored plot inventories (464 individuals in 10 transects) and built stochastic population models. The deterministic stochastic growth rate values (λ) did not significantly differ (F = 2.76; p>0.076) among the three sites over the 2006–2019 period. The long-term stochastic growth rate was λs ¼ 0.973 [0.932, 1.034]. The matrix elements that had the largest effect on λ were the transition to and stasis within the largest size class. Transient responses explained an average of 86% of the variation in the observed population growth rates R2 for rTD vs:robs ð Þ, compared to 4% of the variation in the vital rates R2 for rVR vs:robs ð Þ. Because transient dynamics are dependent on the population size composition, we ran extinction risk analyses under two scenarios: a population composed mainly of juveniles and another composed mainly of adults. There was little risk of falling below the quasi-extinction threshold before 25 year for both juveniles and adults. However, the risk of quasi-extinction was almost certain for both size classes by 80 year. We also simulated the effect of increasing the hurricane occurrence probability over 80 year on the population. There was little risk of extinction before 20 year in the baseline model, but there was a significant risk of extinction within 5 year when 90% of the individuals were affected by a new hurricane event

Spatiotemporal effects of Hurricane Ivan on an endemic epiphytic orchid: 10 years of follow-up

Background: Hurricanes have a strong influence on the ecological dynamics and structure of tropical forests. Orchid populations are especially vulnerable to these perturbations due to their canopy exposure and lack of underground storage organs and seed banks. Aims: We evaluated the effects of Hurricane Ivan on the population of the endemic epiphytic orchid Encyclia bocourtii to propose a management strategy. Methods: Using a pre- and post-hurricane dataset (2003–2013), we assessed the population asymptotic and transient dynamics. We also identified the individual size-stages that maximise population inertia and E. bocourtii’s spatial arrangement relative to phorophytes and other epiphytes. Results: Hurricane Ivan severely affected the survival and growth of individuals of E. bocourtii, and caused an immediate decline of the population growth rate from λ = 1.05 to λ = 0.32, which was buffered by a population reactivity of ρ1 = 1.42. Our stochastic model predicted an annual population decrease of 14%. We found an aggregated spatial pattern between E. bocourtii and its host trees, and a random pattern relative to other epiphytes. Conclusion: Our findings suggest that E. bocourtii is not safe from local extinction. We propose the propagation and reintroduction of reproductive specimens, the relocation of surviving individuals, and the establishment of new plantations of phorophytes.This work was supported by the Inter-ministerial Commission for Science and Technology under Grant [CICYT-Spain, Project CGL2015-69985-R]; and the Havana Project of the University of Alicante

Notas acerca de la colección de Orchidaceae del Herbario del Instituto Superior Pedagógico de Pinar del Río (HPPR), Cuba

S e o f r e c e u n a r e v i s i ó n y u n l i s t a d o d e l a f a m i l i a O r c h i d a c e a e d e p o s i t a d a e n e l H e r b a r i o d e l a Facultad de Biología del Instituto Superior Pedagógico de Pinar del Río, Cuba. La colección de orquídeas depositada en este Herbario es casi desconocida para los estudiantes de la orquideoflora cubana y se dis- tingue por el mejor y más extenso número de ejemplares provenientes de la provincia de Pinar del Río, para la cual se comunica alrededor de la tercera parte de todas las orquídeas registradas en Cuba. A revision and a checklist of the Orchidaceae specimens kept at the Herbario of the Facultad de Biología, Instituto Superior Pedagógico de Pinar del Río, Cuba, are presented. The orchid collection of this herbarium is almost unknown to the students of the orchid flora of Cuba, and it hosts the better and larger collection of specimens from the province of Pinar del Río, from which a third part of all orchid taxa from Cuba are recorded.

Estructura y ecología de la población del endemismo cubano Broughtonia cubensis (Orchidaceae), en Cabo San Antonio, península de Guanahacabibes, provincia de Pinar del Río, Cuba

Se analizan algunas características de la estructura poblacional de Broughtonia cubensis, orquídea epífita endémica de Cuba, en Cabo San Antonio, península de Guanahacabibes, provincia de Pinar del Río, mediante el análisis de diez transectos. Esta especie presenta una distribución agregada con una alta competencia intraespecífica. Además, muestra una elevada selectividad en la especie de forofito sobre la que habita, presentando una marcada preferencia por Plumeria tuberculata y Erythroxylum areolatum. Predomina la presencia de la especie sobre corteza lisa o rugosa y en orientación norte y este. Se discute la hipótesis de la calidad de sitios en relación a la posible presencia de micorrizas. Finalmente, dentro del área abarcada por los 10 transectos, se ha encontrado que esta especie tiene una estructura metapoblacional con una zona núcleo localizada entre el bosque semideciduo y la vegetación de pantano.We analyze some structural characteristics of a population of Broughtonia cubensis, an epiphytic orchid endemic to Cuba, in Guanahacabibes peninsula, Pinar del Rio province, involving ten transects. This species showed an aggregate distribution with a high coespecific competition. It is selectively found on Plumeria tuberculata and Erythroxylum areolatum phorophytes. They are found predominately on individuals with smooth or rugose barks and in north and east orientation. The quality hypothesis of sites is discussed in relation to the possible presence of micorrhizae. Finally, inside the area included by the 10 transects, this species has a metapopulational structure with a nuclear zone located in the area between the semidecidous forest and the marsh vegetation

Long-term hurricane effects on populations of two epiphytic orchid species from Guanahacabibes Peninsula, Cuba

Disturbances affect the spatial and temporal dynamics of ecosystems. The lack of long-term demographic data affects our understanding the effects of high intensity disturbances such as hurricanes. In this paper we assess population recovery of two epiphytic orchids, Broughtonia cubensis (Lindl.) Cogn. and Dendrophylax lindenii (Lindl.) Bentham ex Rolfe, for 7-8 years after Hurricane Ivan (September 2004, category 5, Saffir-Simpson scale). To analyze some spatial components, we applied recent techniques of marked point pattern analysis to ask two questions: 1) at level of phorophytes, was the height and basal diameter (DBH) related to the damage caused by hurricane Ivan, and 2) was the height of epiphytic orchids on phorophytes related to the damage, too? We found that phorophyte damage caused by the hurricane depends on the ecosystem in which the trees were found. Furthermore, damage to individuals of B. cubensis was independent of their height above ground, in contrast to those of D. lindenii. To assess orchid recovery we compared pre- and post-hurricane measures of vegetative traits: number of leaves and leaf area for B. cubensis and number of living roots and mean root length for the leafless D. lindenii. We also compared changes in the production of inflorescences, flowers, and fruits over this recovery period. We found that vegetative parts of B. cubensis recovered, whereas those of D. lindenii did not. However, neither reproductive effort nor success returned to pre-hurricane levels for either species. The greatest decline in fruit set was by D. lindenii, which may reflect a significant decline in availability of their sphingid pollinators. The relative population growth rate from 2004 to 2012 for B. cubensis indicates that the population has stabilized. Unfortunately, analysis of our eight-year data set (2003-2011) for D. lindenii shows negative population growth. Despite an evolutionary history exposed to severe periodic storms not all orchid species are resilient

Efecto del patrón de agregación en algunas variables vegetativas y de la biología reproductiva de tres especies de orquídeas de la Península de Guanahacabibes, Cuba

This paper is aimed to present an analysis of possible implications of the addition of individuals over some variables of the reproductive biology on the population of three species of epiphyte orchids which are present at the Peninsula of Guanahacabibes, Broughtonia cubensis, Encycliabocourtii y Dendrophylaxlindenii, the first two are endemics of Cuba. The results of this study reveal that the addition of individuals produces a negative effect over the chosen variable at Broughtonia cubensis, partially on Encyclia bocourtii, while over Dendrophylaxlindenii no negative incidence is appreciated. The results indicate that addition of individuals acts differently over the reproductive biology of tropical orchids species.En el presente estudio se realiza un análisis de la posible implicación que tiene la agregación de individuos sobre algunas variables de la biología reproductiva en poblaciones de tres especies de orquídeas epífitas presentes en la Península de Guanahacabibes, Broughtonia cubensis, Encycliabocourtii y Dendrophylaxlindenii, las dos primeras endémicas de Cuba. Los resultados indican que la agregación ejerce una acción negativa sobre las variables escogidas en Broughtonia cubensis, parcialmente en Encyclia bocourtii, mientras que sobre Dendrophylaxlindenii no se aprecian incidencias negativas. Todo lo anterior nos indica, que la agregación de individuos actúa indistintamente sobre la biología reproductiva de especies de orquídeas epífitas tropicales

Dinámica de cambios en la biomasa de la población de Encyclia bocourtii Mújica & Pupulin (Orchidaceae) y su relación con los impactos del huracán Iván en la Pení­nsula de Guanahacabibes, Cuba

The changes produced in the number of pseudobulbs, leaves and leaf area of Encycliabocourtii, a species of orchid which is endemic to San Antonio Cape, Guahacabibes Peninsula, before and after the impact of a hurricane of great intensity are analized. To do so, the individuals from the initial cohort are taken into consideration, those which still remain within the popullation since before the impact (2004) and 3 years later (2007). It was concluded that the species sufers severe decreasement regarding the indicators mentioned before, mainly in the number of leaves and leaf area. A slow recovery rate is observed and, only in the number of leaves, the differences are not significant regarding the data collected pre-impact.Se analizan los cambios que se producen en el número de pseudobulbos, hojas y área foliar de Encyclia bocourtii, especie de orquídea endémica de Cabo San Antonio, Península de Guanahacabibes, pre y post-impacto de un huracán de alta intensidad. Para ello se tienen en cuenta los individuos de la cohorte inicial que se mantienen en la población desde antes del impacto (2004) hasta tres años después (2007). Se concluye que la especie sufre graves decrecimientos en los indicadores antes señalados, excepto en el número de hojas y área foliar, en los que las diferencias no son significativas al compararlas con los valores obtenidos pre-impacto

Transient Population Dynamics of Two Epiphytic Orchid Species after Hurricane Ivan: Implications for Management

Populations of epiphytic orchids in disturbance-prone environments rarely reach stable-stage equilibrium. We characterized the post-disturbance, transient dynamics of two epiphytic orchids, Broughtonia cubensis, and the leafless Dendrophylax lindenii, comparing the following indices: reactivity/first-time attenuation, maximal amplification/attenuation, and amplified/attenuated inertia. We also assessed the effects of reintroducing only seeds or only adults, by examining the elasticity of the inertia on the vital rates. For 2006–2010, the stochastic growth rate of D. lindenii was λs = 0.94, or a 6 percent decrease per annum. First-time step attenuation indicates that in 1 year, the population could decrease by an additional 16 percent, and in the worst-case scenario could decrease by almost half, relative to the stable-stage distribution, in 10 years. Broughtonia cubensis had a λs = 1.03; reactivity and first-time step attenuation indicates that in 1 year, the population should not change by more than 14 percent of the estimated stable-stage distribution. However, the worst-case scenario projected a reduction of 40 percent relative to the stable-stage distribution within 8 years. A comparison of reintroduction strategies assessed by elasticity of the population momentum showed that adults performed better when relocated to new habitats.Las poblaciones de orquídeas epífitas en ambientes propensos a perturbaciones rara vez alcanzan el estado de equilibrio estable. Comparamos la dinámica poblacional post-huracán de dos orquídeas epífitas, una áfila, Dendrophylax lindenii y otra con hojas, Broughtonia cubensis a través los siguientes índices: reactividad/atenuación al primer año; la amplificación y atenuación máxima y amplificación/atenuación en la inercia. También evaluamos los efectos potenciales de una reintroducción con sólo semillas o con sólo los adultos, a través de la elasticidad de la inercia en las tasas vitales. Para el período 2006-2010, la tasa de crecimiento estocástico de D. lindenii era λs = 0.94, equivalente a una disminución del 6 por ciento anual. La medida de la atenuación al año indica que la población podría disminuir en un 16 por ciento adicional y, en el peor de los casos, se reducirá a casi la mitad en relación a la distribución estable en 10 años. Broughtonia cubensis mostró un λs = 1,03; la reactividad y la atenuación indican que en 1 año la población no debe disminuir o aumentar en más del 14 por ciento en relación a la estructura estable. Sin embargo, en el peor de los casos, se predice una reducción del 40 por ciento con respecto a la distribución estable a los 8 años. Una comparación de las estrategias de reintroducción evaluadas por la elasticidad de la inercia demográfica mostró que los adultos tuvieron un mejor desempeño cuando fueron trasladados a nuevos hábitats.This study has been carried out as part of the ELENA project (CGL2012-31668) funded by the Spanish Science and Innovation Ministry (MICINN) and by the FEDER program of the European Union

Análisis de la selección de sustrato por parte de Dendrophylax lindenii (Orchidaceae) en Cabo San Antonio , Península de Guanahacabibes, Pinar del Río, Cuba

In this study we analysed the host-tree preference by the epiphytic orchid Dendrophylax lindenii in Cabo San Antonio, Península de Guanahacabibes, Cuba. We surveyed two transects of 1000 metres and variable widht, according to the topography. We noted the presence of the orchids and number counted all the individuals as well as the DBH at the insertion point of this orchid on the phorophytes and the height of trees in the semi-deciduous forest. We recording 344 individuals on 19 species of host tree (phorophyte).D. lindenii shows generalist behaviour on habitat selection, diameter and height insertion on host trees. The orchid was mainly found on Comocladia dentata, Diospyros crassinervis and Cedrela odorata. More than 54,4% of the D. lindenii were found on Comocladia dentata (24,4%), Sideroxylon foetidissimum (10,8%), Diospyros crassinervis (9,9%) y Tabebuia angustata (9,3%). Conservation effort should include the conservation of trees that are most frequently phorophyte of the orchid, especially the two species of trees which have commercial value, D. carsinervis y C. odorata.Se evalúa la preferencia de selección de sustrato por Dendrophylax lindenii, especie de orquídea epífita presente en Cabo San Antonio, Península de Guanahacabibes, Cuba. Se realizó un muestreo de todos los individuos de D. lindenii en dos transectos de 1000 m cada uno y ancho variable de acuerdo a la topografía del terreno. D. lindenii se encuentra sobre 19 especies diferentes de forofitos. Las especies más frecuentes fueron Comocladia dentata, Diospyros crassinervis y Cedrela odorata. Se localizaron un total de 344 individuos de D. lindenii, el 54,4% de los mismos se encuentran sobre Comocladia dentata (24,4%), Sideroxylon foetidissimum (10,8%), Diospyros crassinervis (9,9%) y Tabebuia angustata (9,3%). No se encontró preferencia por la altura o el DBH de las especies de árboles que ocupa. Las estrategias de conservación de D. lindenii deberían incluir la protección de las especies de árboles donde predomina esta especie de orquídea, en particular las dos especies con valor económico D. crassinervis y C. odorata

Encyclia cajalbanensis (Orchidaceae), una especie nueva de la flora cubana

Se describe e ilustrra una nueva especie de Encyclia, endémica de la meseta de Cajálbana en Cuba. Encyclia cajalbanensis es parecida a E. fucata, de la cual se diferencia por el mayor tamaño de las plantas y por el labelo mucho más grande, con el lóbulo medio reniforme, suborbicular.A new species of the genus Encyclia, endemic to the Cajálbana plateau in Cuba, is described and illustrated. Encyclia cajalbanensis is similar to E. fucata, from which it differs by the greater size of the plant and the much larger lip, provided with a reniform-suborbicular midlobe.