Variations in seed size and seed mass related to tree growth over 5 years for 23 provenances of Quercus acutissima from across China

The origin of a seed strongly impacts its traits, and both origin and seed traits influence seed germination and seedling development. However, in many instances, this effect on the seedling does not persist into adulthood, and little is known about how seed traits and original environment affect seedling/tree growth over time. In this study, seed size, seed mass, seedling/tree growth and origins were collected and determined for 23 provenances of Quercus acutissima from across China. Origin variables correlated well with seed size and seed mass. In stepwise multiple regressions, a longitudinal aridity index explained 49.2-68.7% of the total variation in seed size and mass, while only seed width was correlated with seedling/tree height (H) and diameter at the ground (D) from seed traits and origins. The total variance in H and D explained by the models decreased over time, for example, the R 2 value of the models for H declined from 0.477 in the first year to 0.224 in the fourth year; no models was significant in the fifth year. These results indicate that seed size, regulated by the longitudinal aridity index strongly impacted seedling and tree growth, but the strength of the influence decreased over time, and disappeared after 4 years.

Decomposition dynamics and ecological stoichiometry of Quercus acutissima and Pinus densiflora litter in the Grain to Green Program Area of northern China

Litter decomposition and ecological stoichiometry of nutrient release is an important part of material cycling and energy flow in forest ecosystems.In a study of the ecological stoichiometry and nutrient release during litter decomposition in a pine–oak forest ecosystem of the Grain to Green Program(GTGP)area of northern China,a typical pine and oak species(PDS:Pinus densiflora Sieb.,QAC:Quercus acutissima Carr.)were selected in the Taiyi Mountain study area.The ecological stoichiometry characteristics of carbon(C),nitrogen(N)and phosphorus(P)and litter decomposition dynamics were studied by field sampling and quantitative analyses.The results showed the following.(1)The decomposition dynamics of both litters was slow-fast-slow.The most important climatic factor affecting the litter decomposition rate from May to October was precipitation and temperature from November to April of the following year.(2)Throughout the 300-day study,in both litters,C of the two litters was released,N first accumulated and was then released,and P exhibited a release-accumulate-release pattern.(3)C:P was significantly higher than C:N and N:P(p<0.05);the C:N of PSD litter was higher than that of QAC(p<0.05),but the N:P of QAC litter was higher than that of PSD litter(p<0.05).The C:N of both litters was very high in the study area,indicating that the nutrient release ability during litter decomposition in the two typical pine–oak forest ecosystems was relatively weak;therefore,more attention should be paid to nitrogen-fixing species and mixed forests in the GTGP area of northern China.

坡向与林分密度对麻栎林生物量的影响

以坡向和林分密度对麻栎(Quercus acutissima)林生物量的影响进行了调查研究,结果表明:麻栎生长在南坡要好于生长在东南坡和北坡,在不同林分密度中以1430株/hm^(2)的密度生物量最大,乔木层生物量比1220株/hm^(2)的密度高39.2%,比1660株/hm^(2)的密度高4.3%。根系生物量以大于1.0 cm粗的根系最大,占60%左右;其次是小于0.2 cm的细根,占13.7%~13.9%;0.2~0.5 cm的细根占11.2%~11.8%;大于0.5 cm的细根占11.4%~12.3%。

多功能经营的森林质量精准提升措施对林分生长的影响——以青岛市西海岸新区藏马山麻栎林为例

2019年,青岛市将全面提升森林质量纳入到行动计划中,开展了一系列的森林质量精准提升项目。本文通过设置监测样地和对照样地定期对青岛市西海岸新区藏马山森林质量精准提升项目区内的麻栎林(Quercus acutissima)的胸径、树高、蓄积生长量以及碳储量进行研究,得到森林质量精准提升措施对麻栎林林分生长的影响。结果表明,对麻栎林采取森林质量精准提升措施,可以改善保留木的生长空间、营养空间,可以不同程度地提高林分的胸径和蓄积生长量,增加森林碳储量。

火焰红栎与麻栎在沂蒙山区的对比试验

以麻栎(Quercus acutissima Carr.)为参照树种,设置耐寒性、抗高温、耐干旱以及生长量等方面的对比试验,评价火焰红栎(Quercus coccinea Muench)在该地区的适应能力。并通过对二者物候期(春季展叶期、秋季叶变色期、冬季落叶期)的观测,为下一步的大规模引种提供科学参考。