Almacenamiento de carbono en la biomasa arbórea de bosques primarios presente en gradientes altitudinales de la región de San Martín, Perú Study of tree diversity and carbon reserves in three altitudinal gradients of primary forests in the San Martín region, Peru

Resumen

La investigación sobre los patrones de las reservas de carbono en árboles es fundamental para los esfuerzos de mitigación y adaptación del cambio climático. El objetivo de este estudio fue analizar la diversidad de árboles y reservas de carbono en tres bosques primarios bajo gradientes altitudinales en la región San Martín, Perú. El estudio estuvo constituido por tres bosques entre los 2 000 - 2 100, 1 600 - 1 700 y 1 000 -1 100 msnm respectivamente. Cada parcela estuvo conformada por 1 000 m2 y se seleccionaron un total de cuatro subparcelas por cada bosque. Se midieron los árboles con una altura ≥2 m y ≥5 cm de diámetro a la altura del pecho (DAP). Asimismo, la similitud florística entre altitudes se evaluó a través de los índices de Jaccard y Sørensen. El Bosque Alto Mayo presentó valores relativamente altos y consistentes en riqueza de especies, variando entre 6 y 8 especies por parcela, con un índice de Shannon de hasta 1,972; Simpson de 0,842 y equitatividad de 0,948. El Bosque Moyobamba alcanzó el promedio más alto de almacenamiento de carbono total, con un valor de 415,95±21,95 t C ha-1; debido al mayor tamaño en diámetro y altura de los árboles. Se encontró que el mayor contenido de carbono por encima y debajo del árbol estuvo influenciado por el DAP y altura total de los árboles.

ABSTRACT

Research on patterns of carbon stocks in trees is critical to climate change mitigation efforts. The objective of this study was to analyze tree diversity and carbon reserves in three primary forests under altitudinal gradients in the San Martín region, Peru. The study consiste d of three forests betwe en 2 000 -2 100, 1 600 - 1 700 and 1 000 -1 100 m a.s.l. respectively. Each plot consisted of 1 000 m2 and a total of four subplots were selected for each forest. Trees with a height ≥2 m and ≥5 cm diameter at breast height (DBH) were measured. Likewise, the floristic similarity between altitudes was evaluated through the Jaccard and Sørensen indices. The Alto Mayo Forest presented relatively high and consistent values in species richness, varying between 6 and 8 species per plot, with a Shannon index of up to 1,972, Simpson of 0,842 and equitability of 0,948. The Moyobamba Forest reached the highest average total carbon storage, with a value of 415,95±21,95 t C ha-1; due to the larger diameter and height of the trees. It was found that the highest carbon content above and below the tree was influenced by the DBH and total height of the trees. ABSTRACT The high genetic variability existing in sweet pepper makes it necessary to obtain homogeneous material, both agronomic and culinary, and molecular characterization facilitates the study of genetic diversity between materials that can be included in genetic improvement programs. The objective of the present study was molecularly characterized 12 pepper accessions from the INIA-CENIAP germplasm bank, using 12 RAPD markers. Leaf tissue was used for DNA extraction, and PCR-RAPD products were separated on 1.5% agarose gels. The best resolution for assessing genetic variability and polymorphism among accessions was observed with primers OPA 02, OPE 03 and OPE 04. 39 fragments were generated, of which 27 were polymorphic (69,23%). The presence-absence matrix allowed calculating the polymorphism percentage, PIC, multivariate cluster analysis UPGMA (dendrogram), using Jaccard distance. The similarity values among the studied genotypes range from 0.00 to 0.77. OPE 03 provided the highest polymorphic information (78.57%) and PIC=0.34. The UPGMA analysis generated two discriminant groups, Group I and similarity distance of 0.20; the accessions: OSP-HOR-10-988, OSP-HOR-10-399, OSP-HOR-14-981 (sweet peppers), OSP-HOR-14-726 (sweet and hot seed peppers), OSP-HOR-19-1047 and OSP-HOR-19-1046 (hot peppers). Group II and distance 0.23: OSP-HOR-10-991, OSP-HOR-14-727, OSP-HOR-10-989, OSP-HOR-10-995, OSP-HOR-11-479 and OSP-HOR-12-1048 (all sweet peppers). PCA coordinates 1 and 2 explained 44.88% of the accumulated variability. The formation of an additional group to that shown in the dendrogram was evident only with the accession OSP-HOR-19-1046 (hot and from another species of the Capsicum genus). Molecular analysis reflected genetic variability and separated the chili pepper materials into distinct groups, possibly associated with the presence/absence of pungency in the accessions.