Caracterización de poblaciones de especies endémicas en bosque tropical seco semideciduo. Parque Nacional Machalilla, Manabí, Ecuador
Creators: name: Castro, Joselyn K.
name: Zambrano, Jimmy J. Cevallos
name: Franco, Francisco X. Pico
name: Peñafiel, Juan C. Palacios
name: Miranda, Esteban Chirino
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Environmental Sciences not elsewhere classified
subject: Ecology
subject: FOS: Biological sciences
subject: Biological Sciences not elsewhere classified
subject: Plant Biology

description: Seasonally dry tropical forests are ecosystems of high endemism and floristic diversity, but they have been relatively not well-studied ecosystems and are very much threatened by anthropic pressures. This study aimed to evaluate the dendrometric and horizontal structure characteristics of the population of 12 endemic plant species in the semideciduous forest of the Equatorial Pacific Coastal Cordillera of the Machalilla National Park, Manabí, Ecuador. This is one of the most extensive protected areas on the Ecuadorian coast, located in the Tumbes-Chocó-Magdalena biogeographic region. It is considered one of the 25 hotspots worldwide. We selected 12 species that hypothetically co-exist in this semideciduous forest (<i>Bursera graveolens</i>, <i>Eriotheca ruizii</i>, <i>Handroanthus chrysanthus</i>, <i>Ziziphus thyrsiflora</i>, <i>Geoffroea spinosa</i>, <i>Myroxylon balsamum</i>, <i>Priogymnanthus apertus</i>, <i>Melicoccus bijugatus</i>, <i>Nectandra reticulata</i>, <i>Simira ecuadorensis</i>, <i>Coccoloba ruiziana, Klarobelia lucida</i>). We studied five 2500 m<sup>2</sup> transects, where dendrometric variables (tree height, diameter at breast height-DBH, basal area, altimetric and diameter classes) were evaluated. We evaluated the horizontal structure variables of populations like absolute/relative abundance, dominance and frequency, and the importance value index (IVI and IVN). In 12,500 m<sup>2</sup>, the results identified 331 individuals. <i>M.</i> <i>balsamum</i> was the highest species (9.41 m), while <i>E.</i> <i>ruizii</i> had the highest DBH (21.03 cm) and the biggest basal area (0.05 m<sup>2</sup>). The species with the highest absolute/relative abundance and frequency were <i>S.</i> <i>ecuadorensis</i> and <i>H.</i> <i>chrysanthus</i>, and the latter had the highest absolute dominance (1.23 m<sup>2</sup>•ha<sup>−1</sup>). <i>S.</i> <i>ecuadorensis</i> presented the highest importance value index based on 100 and 300, followed by <i>H.</i> <i>chrysanthus</i> and <i>Z.</i> <i>thyrsiflora</i>. <i>P.</i> <i>apertus</i>, <i>M.</i> <i>balsamum</i>, <i>E.</i> <i>ruizii</i> and <i>C.</i> <i>ruiziana</i> obtained intermediate values. The least ecological weight was for <i>N.</i> <i>reticulata</i>, <i>K.</i> <i>lucida</i>, <i>M.</i> <i>bijugatus</i> and <i>G.</i> <i>spinosa</i>. No <i>B.</i> <i>graveolens</i> individuals were observed in the studied transects in this forest because this species was found at altitudes &lt; 240 m a.s.l. The results of the altimetric and diameter classes indicated that the studied sector corresponds to a relatively young secondary forest affected by natural and anthropic factors. Seasonally dry tropical forests are relatively not well-studied ecosystems. Consequently, we suggest to policymakers, to incentive the development of research on dendrology and horizontal structure of endemic forest species of economic, social and cultural interest in these ecosystems to facilitate decision-making in forest management.The illegal extraction of wood in seasonally dry tropical forests is one of the main factors that lead to the degradation of these vegetal formations; therefore, we suggest to managers and politicians to implement surveillance measures and control mechanisms to prevent the illegal extraction of wood in these ecosystems.Seasonally dry tropical forests are ecosystems of high endemism and floristic diversity, but they are very much threatened by anthropic pressures. We suggest to policymakers: (1) to develop integrated management plans prioritizing the conservation of protected ecosystems and forest species of economic, social and cultural interest, and (2) to promote environmental education on the importance of conserving protected ecosystems and key forest species. Seasonally dry tropical forests are relatively not well-studied ecosystems. Consequently, we suggest to policymakers, to incentive the development of research on dendrology and horizontal structure of endemic forest species of economic, social and cultural interest in these ecosystems to facilitate decision-making in forest management. The illegal extraction of wood in seasonally dry tropical forests is one of the main factors that lead to the degradation of these vegetal formations; therefore, we suggest to managers and politicians to implement surveillance measures and control mechanisms to prevent the illegal extraction of wood in these ecosystems. Seasonally dry tropical forests are ecosystems of high endemism and floristic diversity, but they are very much threatened by anthropic pressures. We suggest to policymakers: (1) to develop integrated management plans prioritizing the conservation of protected ecosystems and forest species of economic, social and cultural interest, and (2) to promote environmental education on the importance of conserving protected ecosystems and key forest species.