Afforestation Species Research Articles

The effect of spraying bacterial and fungal solutions on Korean pine Pinus koraiensis Sieb. et Zucc. cone development and seed quality when sprayed during the flowering phase.

Korean pine is an economically essential afforestation species limited by the unreasonable collection of cones, indiscriminate use of chemical pesticides and pest damage. This study aimed to determine whether spraying bacterial or fungal solutions affected insect pests, cone development, and the seed quality of Korean pine Pinus koraiensis Sieb. et Zucc. The experiment was conducted in a forest plantation in Linkou County (Heilongjiang, China) in 2019. Four fungal strains and one bacterial strain were applied during the flowering phase of Korean pine. The results after a year and a half of study indicated that a high concentration of Bacillus thuringiensis 223176 promoted cone development, increased seed weight, and reduced the proportion of damaged cones. Under this treatment, there were 15.873% damaged cones; the seed weight reached 0.829 g, and there were 82.738% fully developed cones. Trees treated with the second most effective strain, Beauveria bassiana 122077, had 30.556% damaged cones and an average seed weight of 0.810 g. Leucanicillium antillanum 01 performed the worst in this study. The seed weight was only 0.775 g, and the damaged and fully developed cones were 52.444 and 41.773%, respectively. In summary, spraying bacterial or fungal solutions during the flowering stage of Korean pine positively impacted seed quality and effectively decreased damage by the lepidopteran species that feed on the cones and seeds in this study.

Effect of different potting media on the early growth of Mansonia altissima (A. Chev)

The effect of different potting media on the early growth of Mansonia altissima was investigated with a view to producing viable and vigorous planting stock of the species for afforestation and reforestation programs. The experiment was laid out in a Completely Randomized Design (CRD) consisting of nine (9) treatments of potting media with 9 replicates; T1- riversand (400g) + topsoil (400g) + poultry manure (400g) + cow dung (400g), T2- riversand (400g) + topsoil (800g) + poultry manure (400g) , T3- riversand (400g) + topsoil (800g) + cow dung (400g), T4- topsoil (1200g) + cow dung (400g), T5 - topsoil (1200g) + poultry manure (400g), T6- topsoil (800g) + riversand (800g), T7- topsoil (800g) + cow dung (800g), T8 - topsoil (800g) + poultry manure (800g) and T9- (control 1600g riversand). Data obtained were subjected to analysis of variance (ANOVA) and mean separation using Duncan Multiple Range Test (DMRT) at 5% level of significance. The results showed that there were significant differences (p<0.05) among the treatments in plant height, stem diameter, leaf and biomass production. T3 had the best performance in plant height (32.78cm), stem diameter (3.49mm) while T7 had the highest leaf production (32.0) and T6, the highest biomass production of 6.25g. However, T9 (control) gave the minimum results of mean plant height (10.10cm), mean leaf production (8.91) and biomass production (1.01g) but T8 produced least stem diameter (1.32mm). The study therefore showed that incorporation of optimum level of organic manure into the potting media will improve growth of M.altissima seedlings.

Canopy Interception of Different Rainfall Patterns in the Rocky Mountain Areas of Northern China: An Application of the Revised Gash Model

Canopy interception is an important part of forest ecosystem hydrological processes. It is the first stage of water distribution when rainfall reaches the canopy and has an important impact on nutrient inputs and water exchange. Pinus tabulaeformis is a main tree species in the rocky mountain areas of Northern China, and it is also a primary species for artificial afforestation. In previous studies of canopy interception, applications of the revised Gash model did not take rainfall characteristics into account. Therefore, in this study, rainfall patterns were divided according to the local rainfall characteristics in the rocky mountainous areas of Northern China. Rainfall was divided into three patterns. Rain pattern A was the main rainfall type. Rainfall patterns B and C were two types of rainstorms. Next, the revised Gash model was used to simulate Pinus tabulaeformis plantations under different rainfall patterns. The results showed that the canopy interception rate of Pinus tabulaeformis plantations in this area ranged from 14.7% to 17.9%. The revised Gash model can be used to simulate Pinus tabulaeformis plantations in the rocky mountainous areas of Northern China, with good simulation results for more than 80% of the conventional rainfall patterns. Furthermore, the canopy interception effect of simulated cumulative rainfall events was better than the individual rainfall event. The simulation effect for special rainfall patterns was not good, so it is necessary to improve the model parameters or collect more rainfall samples. These results can be used to explore the applicability of the revised Gash model in Pinus tabulaeformis plantations in the rocky mountain areas of Northern China. They also demonstrate different applicability of the model under different rainfall characteristics.

Incorporating stand density effects and regression techniques for stem taper modeling of a Larix principis-rupprechtii plantation.

Stem form is the shape of the trunk, differs among tree species and mainly affected by stand density factor. Accurate taper equations are crucial for estimating the stem diameter, form and tree volume, which is conducive to timber utilization and sustainable forest management and planning. Larch (Larix principis-rupprechtii Mayr.) is a valuable afforestation species under large-scale development in North China, but no study on the effect of density on its stem taper has been reported yet. The dataset included 396 analytical trees from 132 standard plots of larch plantation in Saihanba, Hebei Province. Based on 12 different forms of models, we explored the optimal basic equation for plantations and the effects of the stand density, basal area, canopy density and different forms of stand density on the prediction accuracy of the variable-exponent models. The variable-exponent taper equation that includes Sd (stand density) was constructed by using nonlinear regression, a nonlinear mixed effect model and the nonlinear quantile regression method. The results indicate that the Kozak’s 2004 variable-exponent taper equation was the best basic model for describing changes in the stem form of larch plantations, and the density factor in the form of improved the prediction accuracy of the basic model. Among the three regression methods, the quantile regression method had the highest fitting accuracy, followed by the nonlinear mixed effect model. When the quantile was 0.5, the nonlinear quantile regression model exhibited the best performance which provides a scientific basis for the rational management of larch plantations.

Anatomical observation and transcriptome analysis of buds reveal the association between the AP2 gene family and reproductive induction in hybrid larch (Larix kaempferi×Larix olgensis).

Hybrid larch is an excellent afforestation species in northern China. The instability of seed yield is an urgent problem to be solved. The biological characteristics related to seed setting in larch are different from those in angiosperms and other gymnosperms. Studying the developmental mechanism of the larch sporophyll can deepen our understanding of conifer reproductive development and help to ensure an adequate supply of seeds in the seed orchard. The results showed that the formation of microstrobilus primordia in hybrid larch could be observed in anatomical sections collected in the middle of July. The contents of endogenous gibberellin 3 (GA3) and abscisic acid (ABA) were higher and the contents of GA4, GA7, jasmonic acid and salicylic acid were lower in multiseeded larch. Transcriptome analysis showed that transcription factors were significantly enriched in the AP2 family. There were 23 differentially expressed genes in the buds of the multiseeded and less-seeded types, and the expression of most of these genes was higher in the buds than in the needles. We conclude that mid-July is the early stage of reproductive organ development in hybrid larch and is suitable for the study of reproductive development. GA3 and ABA may be helpful for improving seed setting in larch, and 23 AP2/EREBP family genes are involved in the regulation of reproductive development in larch.

Contrasting water-use patterns of Chinese fir among different plantation types in a subtropical region of China.

Plantation cultivation plays an important role in improving terrestrial ecosystem functions and services. Understanding the water-use patterns of major afforestation species is vital for formulating ecological restoration strategies and predicting the response of plantation to climate change. However, the impacts and drivers of forest types on water-use patterns of key tree species are poorly understood. Here, the combined methods of dual stable isotope of δD and δ18O and Bayesian mixed framework (MixSIAR) were employed to investigate the water-use patterns of Cunninghamia lanceolata (Chinese fir) in a monoculture, mixed forest with Cinnamomum camphora, and mixed forest with Alnus cremastogyne under different rainfall events in subtropical China. Furthermore, the relative contribution of different soil and plant factors to the water-use patterns of Chinese fir was quantified using a random forest model. Our results showed that Chinese fir in the mixed forests (with C. camphora or with A. cremastogyne) utilized less water from shallow soil compared to that in a monoculture but significantly improved the proportion of water absorbed from deep soil with the increase of 55.57%–64.90% and 68.99%–108.83% following moderate and heavy rainfall events, respectively. The most important factors contributing to the differences in water-use patterns of Chinese fir among monoculture and mixed forests were tree attributes (i.e., leaf biomass, eco-physiological regulation, and fine root biomass). These findings reveal that Chinese fir in mixed forests could optimize water-use patterns by adjusting plant properties for interspecific niche complementarity, improving the utilization of deep soil water. Overall, this study suggests that mixed-species plantations could improve water-use efficiency and reduce the sensitivity of tree species to precipitation change, indicating they are better able to cope with expected climate variability.

Contrasting responses in growth, photosynthesis and hydraulics of two subtropical tree species to cadmium contamination as affected by elevated CO2 and nitrogen addition.

Plant growth, photosynthesis, and hydraulics are affected by heavy metals but also by elevated atmospheric CO2 concentration (e[CO2]) and nitrogen (N) deposition. However, few studies have investigated the response of woody species to the combined effects of these three factors. We conducted an open-top chamber experiment with two common subtropical trees (Acacia auriculiformis and Syzygium hainanense) to explore the effects of cadmium (Cd)-contamination, e[CO2], and N addition on plant eco-physiological traits. We found that the growth of A. auriculiformis was insensitive to the treatments, indicating that it is a Cd-tolerant and useful afforestation species. For S. hainanense, in contrast, e[CO2] and/or N addition offset the detrimental effects of Cd addition by greatly increasing plant biomass and reducing the leaf Cd concentration. We then found that e[CO2] and/or N addition offset the detrimental Cd effects on S. hainanense biomass by increasing its photosynthetic rate, its N concentration, and the efficiency of its stem water transport network. These offsetting effects of e[CO2] and/or N addition, however, came at the expense of reduced xylem hydraulic safety resulting from wider vessels, thinner vessel walls, and therefore weaker vessel reinforcement. Our study suggests that, given future increases in global CO2 concentration and N deposition, the growth of Cd-tolerant tree species (like A. auriculiformis) will be probably stable while the growth of Cd-sensitive tree species (like S. hainanense) might be enhanced despite reduced hydraulic safety. This also suggests that both species will be useful for afforestation of Cd-contaminated soils given future global change scenarios.

Effect of afforestation mode on rhizosphere soil physicochemical properties and bacterial community structure of two major tree species in Xiong’an New Area

Two major afforestation species in Xiong’an New Area: Armeniaca vulgaris and Sabina chinensis were selected as research objects. We determined soil physicochemical properties in pure stands of the two species, and mixed stands incorporating study species with other common species, then evaluated the structure and diversity of bacterial communities using high-throughput sequencing. Our results showed that: (1) Rhizosphere soil properties of two afforestation species responded differently to various afforestation modes, the concentration of total nitrogen, total carbon and total phosphorus in S. chinensis rhizosphere soil was improved after mixing with broadleaved species, but available nutrients deficiency appeared in most mixed stands. (2) Bacterial diversity increased in mixed stands, especially for S. chinensis, as indicated by ACE and Chao1. The relative abundances of bacterial taxa varied greatly under different afforestation modes. Some taxa that contributed to organic matter decomposition and nutrient cycling were enriched in S. chinensis mixed stands, for example MND1, uncultured_bacterium_f_Gemmatimonadaceae, and uncultured_bacterium_o_Rokubacteriales. RB41 and Bryobacter with such functions were enriched in A. vulgaris mixed stands. All of them were genera from the common bacterial phylum. (3) The concentration of total carbon, nitrate nitrogen, available phosphorus, pH, soil moisture content and total nitrogen could well explain the variations of soil bacterial community. Our results suggested that, mixing of different species helped trees to make full use of nutrients and increased soil bacterial diversity, but it also caused insufficient available nutrient reserves. To improve soil quality of Xiong’an Millennium Forest, develop its capacity in greening and carbon sequestration, we recommend planting more mixed plantations including both coniferous and broadleaf species, while looking for a suitable method to replenish soil nutrients, further optimizing tree growth conditions.

Study on the variation in and selection of Fraxinus mandshurica provenances and families in northeast China

Fraxinus mandshurica Rupr. is one of the main afforestation species in northeast China, and there is great demand for improved F. mandshurica varieties. The results of an investigation into and analysis of the growth traits of F. mandshurica provenances and families showed that there were significant differences in different periods. However, variations in growth traits decreased year by year. There was a significant negative correlation between tree heights of the provenances and sunshine hours in their areas of origin. The provenances of Xinglong, Hailin and Wuchang were selected based on the volume of 18-year-old trees. The average genetic gain from the selection of fast-growing provenances was 19.4%. Ten superior fast-growing families were selected. The average volume of the selected families was 22.6%, higher than that of all families. The correlation coefficient between heights at 6-year-old and at 18a was 0.838 for provenances, and between heights at 4-year-old and at 18-year-old was 0.303 for families. These results indicate that early selection for height in provenances or families could be performed at 6 years or 4 years, respectively. Early selection for DBH and volume in families could start at 8 years.

Net ecosystem exchange of Pinus sylvestris var. mongolica plantation in the western Liaoning Province, China

Pinus sylvestris var. mongolica is one of the important tree species for afforestation in Three-North Regions of China. Investigating net ecosystem exchange (NEE) and its influencing factors is of significance in understanding carbon balance of P. sylvestris var. mongolica plantation . We used the eddy covariance system and its supporting instruments to measure NEE and environmental factors of P. sylvestris var. mongolica plantation in the western Liaoning Province in 2020. The results showed that, at the half-hour scale, plantation emitted carbon during nighttime and sequestrated carbon over daytime. Carbon sequestration was inhibited by drought stress in the afternoon from May to August. At the daily scale, seasonal dynamics of nighttime NEE were mainly controlled by soil temperature and moisture, while that of daytime NEE were mainly controlled by soil moisture and vapor pressure deficit due to drought stress. When soil was dry, precipitation promoted nighttime and daytime NEE and improved photosynthetic and respiration parameters. At the month scale, there was significant negative linear relationship of daytime NEE with ecosystem apparent quantum yield and ecosystem maximum photosynthetic capacity. When air temperature was lower than 5 ℃, ecosystem respiration rate at 10 ℃ and temperature sensitivity of ecosystem respiration increased linearly with decreasing air temperature. The cumulative NEE of P. sylvestris var. mongolica plantation was -145.17 g C·m-2, indicating a weak carbon sink in 2020.

Ectomycorrhizal Fungi Associated With Pinus sylvestris var. mongolica Were Altered by Soil Environments With Aging Plantation in a Semi-arid Desert

Pinus sylvestris var. mongolica (P. sylvestris) is a pioneer afforestation species for wind and sand fixation in northern China. However, most plantations have undergone unprecedented degradation since the early 1990s. Ectomycorrhizal (EcM) fungi are expected to be substantially related to the degradation of P. sylvestris plantations; however, the direct evidence for this remains unclear. For this purpose, we investigated variation among EcM fungal communities associated with P. sylvestris root samples of three age groups (half-mature, near-mature, and mature) in Mu Us Desert. Our results found a total of 72 EcM fungal operational taxonomic unit (OTU) belonging to Basidiomycota (63) and Ascomycota (9). The EcM fungal community is highly enriched in Rhizopogon, Tuber, Tomentella, and Inocybe, and the variations of their abundance mainly contribute to community differences. The diversity index and fungal species richness showed increasing trends toward the mature forest but did not reach a significant level (p > 0.05). The main factors that affected the dominant EcM fungal community were URE, INV, and SOC, but for the whole EcM fungal community, the effects of soil environments with plantation aging are not significant (p > 0.05). Understanding the effects of environmental factors on the structuring of the EcM fungal communities is critical to sustainable forest management in the future.

Growth response of plantations Hippophae rhamnoides Linn. on different slope aspects and natural Caragana opulens Kom. to climate and implications for plantations management

Dendroecology is an effective way to measure the radial growth of plants under different environmental conditions, since the results may provide implications for plantations management. In this study, we examined the growth response of planted shrub Hippophae rhamnoides on different slope aspects and scattered distributed natural Caragana opulens to climate in the western Loess Plateau. The results show that insufficient precipitation from April to June is the main limiting factor of planted H. rhamnoides growth in the western Loess Plateau. On different slope aspects, the H. rhamnoides was susceptible limited by precipitation and drought stress on shady slopes than sunny slopes, with precipitation model explaining 53.0 % of radial growth variation on shady slopes and 30.6 % of growth variation on sunny slopes. Planting density is the main reason for the above phenomenon. Sufficient precipitation and moderate planting density (around 3300 shrubs per hectare) may mitigate the limitations of drought on planted H. rhamnoides growth. In addition, the growth of natural C. opulens was less affected by precipitation and drought stress compared to the planted H. rhamnoides in same region, precipitation and drought model explaining only 14.6 % and 10.5 % of growth variation, respectively, this may promotion appropriately as a suitable afforestation species in the western Loess Plateau. Therefore, the slope aspects, planting density, as well as the limiting factors and time on growth of plantation species should be full considered to vegetation restoration in the future, and thereby, improve the stability and sustainable development of plantation forests in the western Loess Plateau.

Scots pine (Pinus sylvestris L.) demonstrates a high resistance against bark stripping damage

Bark stripping damage reduces timber quality due to fungal infection and structural defects. Weakened stems may break and induce the death of trees, which strongly affects forest stability. Some tree species, such as Norway spruce (Picea abies [L.] Karst.), are highly susceptible to bark stripping, but Scots pine (Pinus sylvestris L.) has been studied to a lesser extent. The objective of this study was to predict the effect of the degree of bark stripping damage and rot on the production parameters of Scots pine and to determine the influence of climatic factors on various damaged trees. The research was conducted on 15 pine forest stands aged 40–42 years with a numerous sika deer (Cervusnippon nippon) population in the western part of the Czech Republic (425–492 m a.s.l.). The results showed significant differences in tree diameter and volume (but not height) between healthy and extensively damaged trees according to 417 pines measured. However, no differences were found between lightly damaged trees. Similarly, circumference damage did not significantly affect mean tree stem volume, in contrast to previously reported results for Norway spruce. The trees were first damaged by deer at the age of 18.5 years on average. According to the prediction model based on 40 felled and sampled trees, rot did not reach a distance > 50 cm from the site of the bark stripping on the stem, with a mean speed of vertical spreading of 0.9 cm yr−1. Concerning the effect of climatic factors on radial growth (60 core samples taken), the difference between healthy and minor to extensively damaged trees was negligible. However, healthy trees responded more to the effects of temperature, and damaged trees were more sensitive to the precipitation amounts. Scots pine appears to be a suitable tree species for afforestation in areas with high game pressure during continuing climate change.

The role of afforestation species as a driver of Hg accumulation in organic horizons of forest soils from a Mediterranean mountain area in SW Europe

Forest areas are a primary sink of atmospheric mercury (Hg) within terrestrial ecosystems, whereas forest vegetation plays a key role in atmospheric Hg transfer to soil horizons. This study assessed variations in total Hg contents (HgT) and accumulation (HgRes) in the soil organic horizons of a forest area in NE Portugal, where post-wildfire afforestation led to the substitution of the native deciduous species (Quercus pyrenaica) by fast-growing coniferous species (Pseudotsuga menziesii and Pinus nigra). The study also evaluated, for each species, the links between Hg contents and other biophilic elements of soil organic matter (C, N, S) present in organic subhorizons (OL, OF, OH). Mean HgT in the organic horizons of the different tree species follow the sequence: P. nigra (88 μg kg−1) < Q.pyrenaica (101 μg kg−1) <P. menziesii (141 μg kg−1). The highest HgRes for the entire organic horizon was found under P. menziesii (471 μg m−2), followed by P. nigra (253 μg m−2) and Q. pyrenaica (189 μg m−2). Among the organic subhorizons, values of HgT and HgRes follow the sequence OL < OF < OH, which is consistent with the degree of organic matter humification. Indeed, HgT and HgRes correlated significantly with the C/N and C/S ratios for all species and organic subhorizons, suggesting that the quality of organic matter may influence strongly the Hg fate in these forest soils. Soils from P. menziesii plots have shown an HgRes 2.5 times higher than in plots dominated by the native Q. pyrenaica. Hg accumulation in the organic horizons, promoted in the coniferous species, may increase the risk of Hg mobilization due to wildfires and forest management practices. Therefore, forest management plans should select cautiously the tree species for afforestation in order to minimize adverse environmental effects caused by changes in the biogeochemical cycle of contaminants such as Hg.

Diversity of Microbial Communities of Pinus sylvestris var. mongolica at Spatial Scale.

Soil microorganisms play an indispensable role in the forest ecosystem. It is necessary to study the soil microorganisms in Pinus sylvestris var. mongolica, which is one of the afforestation species widely planted in the northern sandy region of China. We collected soil samples of P. sylvestris at large spatial scales and analyzed bacterial and fungal community composition differences using high-throughput sequencing techniques. The results showed that: (1) the richness index of different sandy lands was significantly different. The α-diversity of bacteria was the highest in Mu Us Sandy Land, and the α-diversity of fungi was the highest in Horqin Sandy Land. (2) The dominant phyla of bacteria were Actinobacteria, Proteobacteria, Chloroflexi and Acidobacteria, while the dominant phyla of fungi were Ascomycota and Basidiomycota. The relative abundance of dominant phyla was different. (3) Temperature and precipitation were the main driving factors of bacterial and fungal community change at large spatial scale. In addition, bacteria were also affected by total nitrogen, soil organic carbon and pH content; fungal community was affected by pH. The microorganisms showed obvious differences in geographical distribution, which could provide ideas for promoting sustainable management of P. sylvestris stand.

Considerations of Forest Distribution and Native Tree Species for Afforestation in the High Altitudes on the Eastern Tibetan Plateau

Forests are the main components of terrestrial ecosystems and play an important role in the protection and construction of the national ecological security barrier. For a long time, China's large-scale afforestation had been practiced in areas with rainfall higher than the 400 mm threshold, but the issue of afforestation in high altitudes on the Tibetan Plateau remains elusive in both practical experience and theoretical exploration. It is worth thinking further about what principles should be followed in the selection of tree species and suitable altitudes for afforestation in high-altitude areas, as well as what experiences and lessons of previous afforestation efforts should be applied in high-altitude areas. As per the law of vegetation zonal distribution, this paper argues that afforestation at high altitudes should comply with the principle of vegetation zonal distribution and the low temperature limitation, and points out that afforestation is feasible only within the forest distribution area and below the altitudes of climate timberlines. Furthermore, we demonstrate the potential spatial areas of afforestation, and determine the local tree species that may be used for afforestation based on the existing problems of afforestation in eastern Tibet. In summary, afforestation in high-altitude areas of the eastern Tibetan Plateau must comply with the law of zonal vegetation distribution, focus on the upper limit of altitude and the selection of suitable tree species, and adopt only suitable native tree species.

塞罕坝地区人工针叶林径向生长对水热条件的响应

PDF HTML阅读 XML下载 导出引用 引用提醒 塞罕坝地区人工针叶林径向生长对水热条件的响应 DOI: 10.5846/stxb202107071814 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金(41771051,41630750) Response of radial growth of artificial coniferous forest to hydrothermal conditions in Saihanba Area Author: Affiliation: Fund Project: the National Natural Science Foundation of China (41771051和41630750) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:树木生长对水热条件响应的研究在揭示气候变化的生态影响中发挥着重要作用。为探讨水热因子对亚洲最大的人工针叶林生长的影响及不同树种生长-水热因子关系特征,选取塞罕坝地区龄级较高的人工针叶林群落的优势树种华北落叶松(Larix principis-rupprechtii)和樟子松(Pinus sylvestrisvar.mongolica),采集树木年轮样芯,并通过年轮宽度数据建立标准年表。通过分析两树种的标准年表数据与气温、地温、降水量、饱和水汽压差等水热因子的相关关系,揭示不同树种对水热因子响应的异同。研究结果显示:华北落叶松的生长受到6、7、9月的干旱胁迫和8月过多降水的限制,同时受到冬季较高的平均地温和降水的促进;樟子松的生长则受到夏季的高温干旱胁迫和8月过多降水的抑制,但8月较高的平均地温以及春季较高的平均最低地温对樟子松的生长存在明显促进作用。塞罕坝地区华北落叶松受干旱胁迫强于樟子松,而樟子松受较低地温的胁迫强于华北落叶松。考虑到区域增温的趋势,推断樟子松应是更适合在塞罕坝等半干旱地区继续进行大面积人工造林和经营管理的树种。 Abstract:The research on the responses of tree growth to the hydrothermal factors in the marginal areas, such as the agro-pastoral ecotone, has played a vital role in revealing the ecological impacts of climate change. To probe into the influences of hydrothermal condition on the artificial coniferous forest growth, and the characteristic features of tree growth to its hydrothermal factors within different coniferous tree species, we chose the Saihanba Area, where the largest artificial coniferous forests in the Asian region were growing, as the sampling area. We sampled the tree ring data in high age-class artificial forests from two dominant afforestation species, the Larix principis-rupprechtii (larch) and the Pinus sylvestris var. mongolica (pine), and built up two standard tree-ring width chronologies for those two species based on lab analyses. Through examining the correlations between the chronologies of the two species and the local climatic factors including air temperature, surface temperature, precipitation, vapor pressure deficit, and so on, we have further revealed the similarities and differences of those two species in responding to the driving hydrothermal factors. The results are shown as follows. The growth of the larch was limited by the drought stress in June, July and September, and by the excessive rainfall in August, but promoted by the warm surface temperature and relatively more precipitation in winter. Similarly, the growth of the pine was confined by the drought stress resulted from the higher temperature in whole summer, as well as by the over-wet rainfall in August, but promoted apparently by the warm surface temperature in August, as well as by the relatively higher level in the lowest mean surface temperature in spring. The above results suggested that in Saihanba Area, the larch confronted more severe drought stress than that the pine did, but at the same time the larch underwent stronger stress in lower surface temperature than that pine did. Concerning the ever-increasing trend of temperature in the whole region in the coming future, we are inclined to predict that the Pinus sylvestris var. mongolica might be a better and more suitable tree species than that of Larix principis-rupprechtii for further afforestation and reforestation management in those large semi-arid regions such as Saihanba and the similar areas. 参考文献 相似文献 引证文献

Hydraulic architecture and safety margin in ten afforestation species in a lower subtropical region

Hydraulic architecture and safety margin in ten afforestation species in a lower subtropical region

Climate Benefit of Different Tree Species on Former Agricultural Land in Northern Europe

The new European Union Forest Strategy for 2030 aims to plant an additional 3 billion trees on non-forest land to mitigate climate change. However, the choice of tree species for afforestation to achieve the maximum climate benefit is unclear. We compared the climate benefit of six different species in terms of carbon (C) sequestration in biomass and the harvested wood substitution in products to avoid carbon dioxide (CO2) emissions from fossil-based materials over the 100-year period by afforesting about ¼ of the available area in northern Europe. The highest climate benefit was observed for larch, both at a stand scale (1626 Mg CO2 eqv. ha−1) and at the landscape level for the studied scenario (579 million Mg CO2 eqv.). Larch was followed by Norway spruce, poplar, hybrid aspen and birch, showing a climate benefit about 40–50% lower than that for larch. The climate benefit of willow was about 70% lower than larch. Willow showed 6–14-fold lower C stocks at the landscape level after 100 years than other tree species. The major climate benefit over the 100-year period comes from wood substitution and avoided emissions, but C stock buildup at the landscape level also removes significant amounts of CO2 already present in the atmosphere. The choice of tree species is important to maximize climate change mitigation.

Predicting the suitable habitats of parasitic desert species based on a niche model with Haloxylon ammodendron and Cistanche deserticola as examples.

Haloxylon ammodendron, an excellent tree species for sand fixation and afforestation in the desert areas of western China, is threatened by climate change and anthropogenic activities. The suitable habitat of this species is shrinking at a remarkable rate, although conservation measures have been implemented. Cistanche deserticola is an entirely parasitic herb that occurs in deserts, is a source of “desert ginseng” worldwide, and has extremely high medicinal value. Little is known about using niche models to simulate habitat suitability and evaluate important environmental variables related to parasitic species. In this study, we modeled the current suitable habitat of H. ammodendron and C. deserticola by MaxEnt based on occurrence record data of the distributions of these two species in China. We grouped H. ammodendron and C. deserticola into three groups according to the characteristics of parasitic species and modeled them with environmental factors. The results showed that bioclimate was the most important environmental parameter affecting the H. ammodendron and C. deserticola distribution. Precipitations, such as annual precipitation, precipitation seasonality, and precipitation in the driest quarter, were identified as the most critical parameters. The slope, diurnal temperature range, water vapor pressure, ground‐frost frequency, and solar radiation also substantially contributed to the distribution of the two species. The proportions of the most suitable areas for Groups 1, 2, and 3 were 1.2%, 1.3%, and 1.7%, respectively, in China. When combined with cultural geography, five hot spot conservation areas were determined within the distribution of H. ammodendron and C. deserticola. The comprehensive analysis indicated that by using MaxEnt to model the suitable habitat of parasitic species, we further improved the accuracy of the prediction and coupled the error of the distribution of a single species. This study provides a useful reference for the protection of H. ammodendron forests and the management of C. deserticola plantations.