Needle Traits Research Articles

The taxonomic status of closely related closed cone pines in Mexico and Central America

A taxonomic study on 14 cone and needle traits of 281 trees from 33 provenances of Pinus oocarpa, P. oocarpa var. ochoterenae, P. patula var. longipedunculata, P. patula var. patula and P. tecunumanii in Central America and Mexico was conducted to quantify the affinity between closely related species. A second objective was to determine the geographic range of P. tecunumanii in Mexico. Cluster analysis placed 52% of all provenances in taxa different from those assigned by field foresters. Trees from 15 provenances of what was locally known as Pinus oocarpa var. ochoterenae from Chiapas were statistically indistinguishable from high elevation Central American sources of P. tecuncumanii when assessed for cone and needle characteristics. However, trees from two provenances known locally as P. oocarpa var. ochoterenae from southwestern Oaxaca, Juquila and Tlacuache, were found to be distinct from P. tecunumanii and may be a variant of P. patula. Canonical discriminant analysis was used to determine the taxonomic affinity among newly formed clusters. The spatial (Mahalanobis) distance between P. tecunumanii and P. patula var. patula, P. patula var. longipedunculata, and P. oocarpa was 42.0, 44.4, and 109.4 respectively, and highly significant. The geographic range of Pinus tecunumanii in Mexico appears to be confined to the state of Chiapas.

Range-wide morphological and anatomical variation in Larix laricina

To investigate the nature of infraspecific variation in Larix laricina (Du Roi) K. Koch, 60 naturally established stands constituting 44 provenances were sampled from throughout the species' range. Cones were scored for nine traits and short-shoot needle transverse sections were scored for seven traits and 20 radial distances. Variation in all traits was minimal, with the greatest components expressed between trees within stands and within trees. Canonical variates analysis of needle traits demonstrated that provenances were differentiated according to location, whereas canonical variates analysis of cone traits showed a much weaker geographic trend. These results are consistent with the hypothesis that Alaska and northern Yukon provenances resulted from geographically separate migratory waves originating from different locations in the south following glacial recession. While Alaska provenances were distinguished from other provenances based on canonical variates analysis of needle data, but not of cone data, this distinction is insufficient to recognize Alaska tamaracks separately at either the species or varietal level.

Morphological and chemical traits of pine needles of trees in a gap caused by root rot

AbstractSome morphological traits of the crown (length and dry weight of needles, length of shoots) and chemical composition of the needles (content of nitrogen, phosphorus, potassium, calcium and magnesium) of a tree remaining in the middle of a Fomes annosus‐rot gap in a 55‐year‐old pine stand, were compared to the same traits from trees at the edges of the gap. The central tree (C) was intermediate in morphological traits. The lowest concentrations of N, P, and K were found in needles of the central (C) tree and, respectively, the highest ones in needles of the tree classified as weakened (I) and standing at the edge of the gap.