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Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The regeneration characteristics of Prunus armeniaca population under grazing disturbance were analyzed, and the relationship between natural regeneration in young plants and its influencing factors was discussed to provide a theoretical basis for optimizing grazing and protecting P. armeniaca resources in wild fruit forests. The wild fruit forests in Xinghuagou of Xinyuan County, Mohuergou of Gongliu County, and Daxigou of Huocheng County were selected as study sites where P. armeniaca are concentratedly distributed in Xinjiang. The grazing degree in the forest land was investigated by combining sample plots with sample lines of cattle tracks. The grazing intensity of each region was divided according to the disturbed degree of the herbaceous vegetation community(height, coverage, and aboveground biomass) in the forest land. The density, growth characteristics, and degree of damage of the naturally regenerated young P. armeniaca plants in each disturbance area were analyzed, and the relationship between the degree of damage in young plants and individual growth size(growing amount) as well as the habitat factors were discussed. The results showed that:(1) the density of natural regeneration in young P. armeniaca plants under light disturbance was the highest(364 tree·hm-2), followed by those of moderate disturbance(247 tree·hm-2) and heavy disturbance(225 tree·hm-2). The average regeneration density was 279 tree·hm-2.(2) The average ground diameter, crown width, tree height, inclination, and trunk height of the natural regeneration saplings of P. armeniaca under were 1.69 cm, 38.72 cm, 77.59 cm, 36.20°, and 35.75 cm, respectively. Significant differences were present in the growth indices under different grazing intensities, but no significant differences were present in the V age class.(3) The damage ratio of naturally regenerated young P. armeniaca plants reached a maximum of 84.48%. There were significant differences in the damage indices of naturally regenerated young P. armeniaca plants under light, medium, and heavy grazing disturbances, with damage indices of 38.52, 58.13, and 43.44, respectively.(4) Ordinal logistic regression analysis showed that the degree of damage to young plants after regeneration was significantly and negatively correlated with shrub coverage and grazing distance. The current grazing intensity of wild fruit forests severely hinders the natural regeneration of the P. armeniaca population. To maintain the sustainable management of wild fruit forests, it is necessary to optimize grazing systems and strengthen human intervention protection. [ABSTRACT FROM AUTHOR]

This study was aimed to investigate the appropriate light conditions for Juglans mandshurica saplings of different ages, and provide a theoretical basis for the development of artificial tending measures for J. mandshurica saplings in the understory. In this study, natural regeneration of J. mandshurica saplings aged 1-3 a (age stage Ⅰ), 4-6 a (age stage Ⅱ) and 7-9 a (age stage Ⅲ) in the experimental forestry farm of Zhuan Shan, Fangzheng County, Harbin City were used as experimental subjects, determining their growth patterns and photosynthetic indicators in different light environments ( forest edge, forest gap and understory). The results showed that: as light intensity diminished, the biomass, saplings height and ground diameter decreased, and the specific leaf area increased; chlorophyll a / b, light compensation point (LCP), the highest maximum net photosynthetic rate (Pmax) and dark respiration rate (Rd ) decreased, chlorophyll content increased in saplings of all ages. In the understory and the forest gap, saplings of age Ⅱ had the highest maximum net photosynthetic rate and chlorophyll content and the lowest values of light compensation point, dark respiration rate and chlorophyll a / b; the highest maximum net photosynthetic rate and light compensation point of saplings increases as saplings age in the forest edge. In summary, the forest edge is more suitable for the growth of saplings. In addition, when artificially tending J. mandshurica saplings between 4 and 6 years old, tending intensity can be reduced appropriately. In contrast, when artificially tending J. mandshurica saplings of 1-3 and 7-9 years old, and light transmittance of the upper forest layer should be strengthened timely. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To deepen our understanding of the role of the microhabitat in seedling colonization, we analyzed the relationship between microhabitat factors and the natural renewal seedling traits of 1-year-old Tianshan spruce (Picea schrenkiana var. tianschanica) seedlings in the central northern slope of the Tianshan Mountains. In addition, we explored the influence of microhabitat factors on seedling traits via ranking analysis. Our results identified 11 microhabitat factors, namely, litter thickness, soil compaction, herb height, herb cover, moss cover, litter cover, altitude, root disc layer thickness, soil weight, soil phosphorus, and soil volume, that significantly affected the seedling traits of natural-regenerated 1-year-old Tianshan spruce seedlings. These factors explained 56.01% of seedling variation, with litter thickness, moss cover, soil compaction, and soil weight accounting for 55.13%. During the natural renewal colonization of Tianshan spruce, the type of ground cover and degree of soil loosening had a strong impact on the traits of 1-year-old seedlings. [ABSTRACT FROM AUTHOR]

Copyright of Xinjiang Agricultural Sciences is the property of Xinjiang Agricultural Sciences Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The research objective is to reveal the effects of thinning intensity with crop tree management and environmental factors on natural regeneration of the mixed stands of Pinus massoniana and Quercus variabilis, so as to provide a scientific basis cultivating multifunctional forests of close-to-nature characteristics. By following crop tree management, 28 quadrats of 5 m×5 m were established in four intensities: weak thinning WT (7. 6%), light thinning LT (15. 3%), moderate thinning MT (24. 3%), and control (CK). The regeneration species richness, species diversity, regeneration density, regeneration frequency, seedling height growth difference at different thinning intensities, and the impact of environmental factors and stand factors on natural regeneration in three different years were analyzed. The result showed that in three consecutive years, 33 natural regeneration species of 23 families and 31 genera, rily prima- broad-leaved species, were recorded; the species richness of natural regeneration at different thinning intensities was greater than CK; and the intrinsic diversity in the following three years after the different thinning was MT>LT>WT>CK. In different years after thinning, there were significant and extremely significant differences in regeneration density between MT and CK (P<0. 05 and P< 0. 01). The mean value of regeneration frequency under different thinning intensities in 3 years was higher than that of CK. The ling seed- height was greater than that of CK at different thinning intensities; increasing the thinning intensity promoted seedling height growth. The canonical correlation analysis between the regeneration group and environmental group revealed that the greater thinning tensity in- together with the gentler slope increased the natural regeneration density and the species richness. The research revealed that the increase of thinning intensity can escalate species richness, species diversity, regeneration density and regeneration frequency, with HT the best, the synergistic negative effect of slope, aspect may offset the positive effect of thinning intensity on natural regeneration to a certain extent, and that the corresponding management countermeasures should be further studied in future management practice. [ABSTRACT FROM AUTHOR]

To explore whether the allelopathy of Metasequoia glyptostroboides litter is an obstacle to its natural regeneration, eight concentrations (200, 100, 50, 20, 10, 5, 2, 1 g·L-1 and CK) of aqueous extracts from fresh and natural litter of M. glyptostroboides were set to analyze the allelopathic effects of aqueous extracts of different types and concentrations on seed germination and growth of M. glyptostroboides. The results were as follows:(1)The aqueous extract of the fresh M. glyptostroboides litter had no significant effects on seed germination rate and germination energy (P>0.05), but had significant effects on germination index (P<0.05), and seed germination was significantly inhibited by 1, 100, 200 g·L-1 treatments. The effects of aqueous extracts of the natural M. glyptostroboides litter on three indexes of seed germination were not significant (P>0.05), but the inhibitory effect was reflected in 5, 10, 50, 200 g·L-1. (2)The shoot length, hypocotyl length and main root length of M. glyptostroboides seeds were significantly different between different concentrations of fresh and natural litter aqueous extracts (P<0.05), and decreased gradually with the increase of aqueous extract concentrations (≥10 g·L-1), especially in the range from 50 to 200 g·L-1. (3)Compared with seed germination, the aqueous extracts of fresh and natural M. glyptostroboides litters had stronger inhibitory effect on the growth of seeds after germination, and the allelopathic effect of fresh litter was stronger than that of natural litter. (4)The main root length was the most sensitive to allelochemicals among seeds germination and growth indexes. (5)The dynamic change of shoot length growth of M. glyptostroboides seeds accords with the “S” type growth curve (R²≥0.988). In summary, the litter of M. glyptostroboides has a certain allelopathic inhibitory effect on its own seed germination and growth, which affects the natural regeneration of its population. It is suggested that the litter under the forest should be properly cleaned to promote the natural renewal of the M. glyptostroboides population in the management of M. glyptostroboides populations. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To identify the key factors involved in hindering and effectively promoting the natural regeneration of Metasequoia glyptostroboides, five M. glyptostroboides mother trees in the original wild habitat were selected for this study. The sample circle was set with the M. glyptostroboides mother tree as the center. Different understory treatments (community barrier, understory living ground cover barrier, litter barrier, and non-barrier) were used to conduct the zoning experiment to study the effects of vegetation and litter on the natural regeneration of M. glyptostroboides. Different understory treatments were found to have significant effects on M. glyptostroboides seedling regeneration density, survival rate, height, base diameter, root length, leaf number, leaf area, aboveground biomass, and underground biomass (P＜0.01) . All seedling germination growth indicators reached their maximum values in the non-barrier area, followed by the litter barrier area, understory living ground cover barrier area, and community barrier area. The living ground, litter, and community environment all hindered the natural regeneration of M. glyptostroboides. The order of inhibition on its seed germination and seedling growth was community environment＞living ground＞litter. The dynamic changes in seedling height exhibited the S type growth curve (R~2≥0.893), whereas the seedling regeneration density in all four treatments displayed an inverted "V" shape distribution. The non-barrier treatment significantly promoted the natural regeneration of M. glyptostroboides, under which the survival rate, seedling height, base diameter, root length, leaf number, leaf area, growth rate, and biomass were the highest. Thus, for the conservation and management of M. glyptostroboides populations, the living ground cover and litter should be adequately cleared to provide a suitable environment for seed germination and seedling growth, and promote the natural regeneration of M. glyptostroboides populations in the future. [ABSTRACT FROM AUTHOR]

The study was conducted to examine the characteristics of natural regeneration and the spatial relation of seedlings and saplings in the mixed stand of Picea spp. + Larix principis-rupprechtii in Guandi Mountain. The spatial distribution pattern and heterogeneity of naturally occurring seedlings and saplings were studied using the method of adjacent lattice combined with the semivariance function. The results showed that the regeneration density of the understory community was 450-1 350 trees • hm-2, which was dominated by Picea spp., accounting for 81.74% of the community. The regeneration density of Picea spp. was 688 trees • hm-2, and that of L. prirzcipis-rupprechtii was 167 trees•hm-2, the latter demonstrating poor regeneration. A majority of the seedlings and saplings were clustered, and the clustering intensity gradually decreasing with increasing scale. A strong spatial autocorrelation was observed between the seedlings and saplings. Structural and random factors were responsible for 79.6% and 20.4% of variations in the distribution pattern, respectively. The spatial distribution of seedlings and saplings demonstrated anisotropy, with a dominant northeast to southwest pattern and subdominant northwest to southeast pattern. The spatial autocorrelation range of the ground diameter and tree height of seedlings and saplings were 11.25 and 13.85 m, respectively. Structural factors had a greater influence on the spatial heterogeneity, which was stronger in the horizontal direction. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of Botanical Research is the property of Bulletin of Botanical Research Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Shenyang Agricultural University is the property of Journal of Shenyang Agricultural University Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to clarify the regeneration status of Larix principis-rupprechtii forest in Guandi Mountain and explore the influence of environmental factors on its regeneration, the seedlings and saplings of three stands of Larix principis-rupprechtii forest were investigated by a field investigation method and the regeneration density was used to reveal the natural regeneration status. The results were as follows: Larix principis-rupprechtii was poorly regenerated, and seedlings and saplings were scarce. In the 10 square plots of 20 m X 20 m, only 17 seedlings and 44 saplings were found gathered on the edges or gaps of the forest. In contrast, there were 621 seedlings and 630 saplings of Picea spp. in the 10 plots, indicating that it regenerated well. Both altitude and slope did not significantly affect the regeneration of the two tree species. The regeneration of Larix principis-rupprechtii was significantly affected by the slope aspect. The regeneration density on the sunny slope was ( 163 ±51) tree. hm -z, which was higher than that of shady slope with only(77±35) tree.hm-2 . The regeneration density was not significantly different among the three stands. The regeneration of Larix principis-rupprechtii was affected by the canopy density of the stands. The maximum regeneration density was 250 tree. hm-2 in stands with a canopy density of 0. 25, and the regeneration density slightly decreased as the canopy density increased. There was no regeneration when the canopy density exceeded 0.80. The regeneration of Larix principis-rupprechtii was also significantly affected by the thickness of the undecomposed litter layer and the unifonnity of the thickness among the three litter layers. Larix principis-rupprechtii was prone to regenerate on plots with the thickness of each litter layer between 2 -4 cm. Light and litter were the main factors affecting the regeneration of Larix principis-rupprechtii on Guandi Mountain. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Southern Agriculture is the property of Journal of Southern Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Casuarina equisetifolia coastal protection forest(C. CPF)is an important barrier of coastal ecology in Hainan Island, and natural regeneration is of great significance for it to play a role of protection function continuously. It is found that undergrowth natural regeneration is difficult in the most area of C. equisetifolia forests in Hainan Island, however, there is a phenomenon of good regeneration in the local area. In order to explore the cause of the great disparity in the natural regeneration, and to provide certain theoretical basis for promoting the transformation of C. CPF from plantation to near-natural forest, the main factors affecting the natural regeneration of C. CPF were studied through the analysis of the differences of regeneration quality for different forest lands. Seventy-three temporary plots were established in the C. CPF in Hainan Island, and statistical methods, such as variance analysis and correlation analysis, were used to study the effects of climate zones, stand conditions, soil factors and litter accumulation on natural regeneration quality and density. The results were as follows:(1)The regeneration of C. CPF in wet zone was significantly better than that in dry zone;(2)There was significantly negative correlation between C. equisetifolia stand density and regeneration density or herb coverage, but other factors of stand conditions had little effect on regeneration;(3)There was no significant diffe-rences in soil pH value and nutrients in the sample plots with different regeneration qualities, but ammonium nitrogen promoted the regeneration of seedlings and organic matter did the regeneration of saplings to some extent;(4)The accumulation of litter was not conductive to natural regeneration as a whole. The results indicate that the climate factor, density of C. equisetifolia stands and accumulation quantity of C. equisetifolia litters were the main impact factors for the natural regeneration of undergrowth in C. CPF. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)