Anatomical and morphological features of the needles of Coulter pine (Pinus coulteri D. Don) under the conditions of the Southern Coast of the Crimea

The article presents the results of studying the anatomical and morphological features of vegetative organs of the North American species Pinus coulteri D. Don when introduced to the Southern Coast of the Crimea (SCC). The research was carried out in the park communities of the SCC using generally accepted methods. The features of the formation of annual growth of shoots, metric indicators of needles, as well as the specifics of morpho-anatomical structures of needles are determined. It was found that the average length of shoots of model trees of P. coulteri in park communities of the SCC varies from 5.1±0.2 to 5.7±0.3 cm. The length of the annual increase under the conditions of introduction is influenced by the amount of precipitation of the previous year (r = 0.91). The length of needles on the SCC is within these values in the natural area, but the average values are slightly lower. Anatomical features of P. coulteri needles are quite stable under various cultivation conditions. P. coulteri needles are stiff due to the increased number of sclerotized hypodermic cells. In P. coulteri needles, some inclusions with essential oil are noted, the maximum amount of which is in the first layer of the mesophyll.

Factors Associated with Establishment and Growth of Pinus coulteri and Pinus sabiniana in California’s Central Coast Bioregion

Forest inventory indicated recent decline in a P. coulteri population at its northern extent but live stems in sympatric P. sabiniana increased. Patterns of cone production, localized factors associated with regeneration, relations between wildfire and tree age distributions, and correlations between climate, seedling establishment, and tree growth were analyzed as potential mechanisms underlying unequal demographics between the two species. Four findings emerged: (1) P. sabiniana had a higher frequency of open cones at the time of observation, but cone production was size-biased, and cone production rates were similar for both species; (2) P. sabiniana seedlings were associated with a higher proportion of bare ground cover and westerly aspects, whereas establishment of P. coulteri seedlings was correlated with warm growing seasons and high vapor-pressure deficits, and seedlings occurred on northernly aspects; (3) age distributions of stands inside and outside a wildfire perimeter did not differ for either species, but annual growth increments of P. coulteri were greater within the fire perimeter; and (4) P. coulteri was even-aged, establishment was episodic, and occurred approximately 10 years post-wildfire. In contrast, the age distribution of P. sabiniana was highly variable, consistent with continuous recruitment, and establishment was not correlated with a climate signal.

Chemical analysis of phenolic compounds and determination of anti-oxidant, antimicrobial and cytotoxic activities of organic extracts of Pinus coulteri

<p class="Abstract">New bioactive natural products, the phenolic composition and the biological activities of organic extracts from the needles of the Algerian <em>Pinus coulteri</em> were investigated. The analysis by HPLC-DAD of crude extract revealed the presence of 10 phenolic acids and nine flavonoids. In vitro anti-oxidant activities were performed using four different tests. The greatest antiradical activity was found in the ethyl acetate fraction (IC₅₀= 3.2 ± 0.3 µg/mL), whereas the diethyl ether fraction had the higher contents of total phenolics and flavonoids and exhibited a highest activity in reducing power and β-carotene–linoleic acid tests with EC₅₀= 67.1 ± 0.4 μg/mL and 71.5 ± 0.2% of inhibition, respectively. Furthermore, a low to moderate antimicrobial activity according to all extracts was revealed against eight bacteria tested. The MIC value of chloroform fraction showed a strong degree of antibacterial activity (&lt;0.09 mg/mL). The crude extract was found toxic with LC₅₀ value of 15.2 μg/mL by brine shrimp toxicity assay. The needle extract of <em>P. coulteri</em> is rich in valuable biologically active compounds and could represent a new resource of anti-oxidant agents for the treatment of diseases.</p><p class="Abstract"><strong>Video Clip of Methodology:</strong></p><p class="Abstract">Disc diffusion test: 6 min 41 sec <a href="https://www.youtube.com/v/-sfOw7qg5ws">Full Screen</a> <a href="https://www.youtube.com/watch?v=-sfOw7qg5ws">Alternate</a></p>

Patterns of pine regeneration following a large, severe wildfire in the mountains of southern California

We examined establishment patterns of pines following a large, severe wildfire in the Peninsular Ranges of southern California, USA. The October 2003 Cedar Fire caused 98% pine mortality. In this study, we asked (i) where did seedlings establish and survive in formerly forested areas of the Cuyamaca Mountains 5 years following the high severity fire and (ii) what factors were associated with the spatial pattern of seedling establishment? Factors analyzed were pre-fire vegetation type, fire severity, post-fire vegetation characteristics, topography (slope, aspect, and elevation), and mapped soil type. We used a unique belt-transect survey method following the existing trail network that resulted in a representative sample of post-fire environments. Almost 1300 100 m × 20 m quadrats were searched in 2008–2009, one third of which supported juvenile pines. Regeneration primarily consisted of Coulter pine ( Pinus coulteri D. Don), a weakly serotinous pine that was establishing at densities of 5–2320/ha on half of the quadrats where it had occurred pre-fire. Pinus coulteri regenerated in areas burned at high severity where pre-fire pine cover was high and its abundance was positively associated with higher elevation and cover of bare soil. In contrast, minimal regeneration of nonserotinous pines occurred patchily in areas that were not severely burned.

Intraspecific Phylogeography and Adaptive Divergence in the White-Headed Woodpecker

This study uses mitochondrial DNA (mtDNA) to examine the phylogeography of the White-headed Woodpecker (Picoides albolarvatus), one of the least-studied woodpeckers in North America. A mismatch distribution and calculation of Tajima's D indicate that the overall phylogeographic history of the species is characterized by a recent range expansion that probably occurred after the start of the Pleistocene. In addition, a nested clade phylogeographic analysis indicates that additional processes such as allopatric fragmentation and restricted gene flow have influenced the evolutionary history of this species. Traditionally, the White-headed Woodpecker has been split into two subspecies whose distributions meet in the northern part of the Transverse Ranges in California. The two subspecies differ morphologically, with the southern subspecies having a larger bill in proportion to its body size than the northern subspecies. Geographical variation in mtDNA is concordant with a division at the Transverse Ranges that corresponds to the morphological variation seen between the two subspecies. An analysis of molecular variance indicates that 27% of the genetic variation results from differences between the northern and southern subspecies. Furthermore, birds in the northern part of the range differ from those in the southern part of the range by at least one base substitution. These results agree with the hypothesis that the larger bill of the southern subspecies is the result of recent local adaptation to feeding on the large cones of Coulter pines (Pinus coulteri).