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A new tree fern of the family Tempskyaceae, Tempskya hailunensis sp. nov., is described herein based on a silicified trunk from the Cretaceous of Hailun City, Heilongjiang Province, Northeast China. The new species is composed of dichotomizing large stems surrounded by a mesh of adventitious roots, petioles, and leaf-like structures, constituting a solid and compact false trunk. The dorsiventral stems contain solenosteles that have long internodes with mostly two leaf traces. The stem cortex consists of a sclerenchymatous outer zone and a parenchymatous inner zone, and the stem pith is divided into a parenchymatous outer zone and a sclerenchymatous inner zone. Wide multicellular scales are attached to the stem epidermis. Leaf-like structures embedded among adventitious roots in the trunk are isobilateral, thick, and without distinct intercellular spaces. Also present are dispersed annuli of sporangia, which are only few cells long and apparently uniseriate. Though it cannot be fully ruled out that these vegetative and fertile remains belong to epiphytes that colonized the Tempskya trunk, the consistent and exclusive occurrence of these particular types of remains makes it likely that they belonged to the Tempskya plant itself. This new species represents only the second fossil record of Tempskya from China, increasing the known diversity of this genus during the Cretaceous both in Asia and globally. Moreover, it provided evidence for recognizing probable leaf structure and growth habit of Tempskya. • A new Cretaceous fern of Tempskya with leaves described from China. • Isobilateral leaf fragments and annuli are present among adventitious roots. • Leaves grew under environment with adequate illumination. [ABSTRACT FROM AUTHOR]

To screen soil nutrients and light conditions that effectively promote the growth of Picea koraiensis saplings and to provide a scientific basis for establishing growth promotion techniques for P. koraiensis saplings, a split-zone design experiment was conducted with P. koraiensis saplings plantations of 8-10 years old in Jiamusi City, Heilongjiang Province, using three light conditions (full light, 0. 5 depression, 0. 7 depression) with nitrogen addition (100 g / plant-yr) and control plots to analyze the effects of light and nitrogen addition on growth and leaf morphological function of P. koraiensis saplings. The results showed that: The annual growth of tree height was the highest under full light conditions, and the annual growth of ground diameter was the highest under full light fertilization conditions, followed by 0. 5 degree of depression; the effect of N addition on the annual growth of tree height and ground diameter was small. Between different light conditions, with the increase of canopy density, the specific leaf area and chlorophyll content increased, leaf dry matter content and chlorophyll a/b decreased, and leaf nutrient content did not change significantly; the effect of N addition on leaf morphology, chlorophyll content and leaf nutrient content was not significant. The effect of light on the growth, leaf morphology and photosynthetic capacity of P. koraiensis saplings was more significant than that of N addition, and saplings under full light and N addition had larger annual growth of tree height and ground diameter, and the lowest annual growth ratio of high diameter. Nitrogen addition can promote the photosynthetic efficiency of saplings. The full light condition or nearly full light condition should be selected for the forestation of P. koraiensis, and the photosynthetic capacity of saplings can be improved by nitrogen addition after forestation to promote growth. [ABSTRACT FROM AUTHOR]