Farzana, MaishaRahman, M. MostafizurFerdous, TaslimaJahan, M. Sarwar...
9页查看更多>>摘要：Key message The leaf and bark extract of Trema orientalis has antioxidant and antibacterial properties. Its bark contains considerable amount of tannin and showed potential for leather tanning. The wood of this species is an excellent source of pulp production. Trema orientalis L. is a fast growing tree in tropic and sub-tropic regions whose leaf, bark and root extract has traditionally been used in therapeutic purposes in different parts of the world. Along with having antioxidant and antibacterial activities within the different plant tissue extracts, it also contains 22% tannin material that is suitable for leather tanning as well as biobased resin preparation. Wood from T. orientalis had good amount of alpha-cellulose (45-50%) and moderate amount of lignin (20-25%) leading to much research on T. orientalis pulping, where pulp yield in the kraft and soda-anthranquinone pulping processes was about 50% with kappa number around 18-25 that made it comparable to tropical hardwood pulp. Dissolving grade pulp with high purity could also be produced from this species which makes it a good alternative for pulpwood production in tropical countries. This review addresses the potential of complete utilization of the T. orientalis plant in biobased product development.
原文链接:
NSTL
Springer Nature
Chalk, Phillip M.Lam, Shu K.Chen, Deli
6页查看更多>>摘要：Key message The proportional contribution of endophytic and phyllospheric diazotrophs to tree N nutrition can be quantified by N-15 techniques. Observations of vigorous growth of Pinus spp. on unreclaimed gravel mining sites, together with measured net nitrogen (N) gains of 50 kg N ha(-1) y(-1) in sand culture, indicate the importance of alternative N sources when soil organic matter (SOM) cannot meet plant demand. Non-nodulated trees can respond positively to inoculation with N-2 fixing bacteria under conditions of low N supply, suggesting that non-nodular symbiotic N-2 fixation can make a significant contribution to tree nutrition, a well-established pathway for cereals, forage grasses and some industrial crops in N-limited environments. We reviewed the literature where non-isotopic approaches and techniques based on stable (N-15) and radioactive (N-13) tracers were used to estimate the relative contribution of endophytic and phyllospheric N-2 fixation to the N economies of non-nodulated trees. The principal avenue of enquiry has so far involved determination of the response of trees to inoculation with diazotrophic bacteria. There is a need to obtain in situ measurements of the reliance of non-leguminous trees on endophytic and phyllospheric N-2 fixation under a range of environmental and edaphic conditions. Current methodological obstacles have to be overcome to meet this challenge. Future research directions are suggested.
原文链接:- NSTL
- Springer Nature
Soares, Bruno Charles DiasLima, Jose Tarcisiode Assis, Claudineia Olimpia
8页查看更多>>摘要：Key message The higher the basic density and the lignin content, the higher the cleavage strength tends to be and the less prone to checking the wood tend to be. The checks that often affect Eucalyptus wood, also called cracks or cleavages, depreciate the material and cause considerable loss of yield in higher value-added products for the sawn wood industry. Information about the influence of basic density and lignin content on the propensity of wood to checks, simulated in a cleavage mechanical test, is scarce in the literature. Therefore, the objective of this work was to investigate and clarify the relationships between the cleavage strength and the basic density and lignin content of the wood within the stem. For this, two Eucalyptus grandis trees were felled at 22 years of age and the stems were sectioned to obtain the base logs, three meters long, which were used during the analysis made in the present research. From these logs, specimens for the cleavage test were made. After the cleavage test, the basic density and lignin content were determined for each specimen, aiming at adjusting regression models that explained the variation of the cleavage strength of the wood as a function of the aforementioned properties. The results showed that the higher the basic density and the lignin content, the higher the cleavage strength tends to be and, consequently, the less prone the wood tend to be to the checks.
原文链接:- NSTL
- Springer Nature
Fernandes, G. WilsonMaia, Renata A.Arantes-Garcia, LucasPereira, Eduardo G....
14页查看更多>>摘要：Key Message Neolithus fasciatus gall affected the host's efficiency to absorb and use the available light and functioned as a sink source for photoassimilates, water, and nutrients that would be allocated to plant development and reproduction of Sapium glandulatum. The knowledge on the effects of galls on the redistribution of resources and reproductive performance of the host is fragmentary. We used a combined approach of physiological and biochemical analyses to investigate the impact of galling on host ecophysiology and performance to aid in the bridging of this gap. We determined the frequency of galled hosts on 155 individuals of Sapium glandulatum in the field. The following ecophysiological parameters: oxidative stress, gas exchange, contents of chlorophyll, flavonoids, water, and total carbohydrates were recorded on galled and ungalled individuals. In addition, the impact of galling was recorded through the number of lateral shoots and fruit production. Approximately 75% of the studied host population had at least one galled shoot, and galls were most abundant on younger leaves. While galled and ungalled individuals did not differ in their oxidative stress, galled individuals showed higher stomatal conductance, internal carbon concentration, and flavonoid production, but lower net photosynthetic rate and effective quantum yield of PSII. Total carbohydrate and content of water were higher in galled tissues compared to healthy tissues of galled and ungalled host leaves. Galling induced attacked shoots to produce ca. four lateral shoots while ungalled shoots did not produce any lateral shoots. Last, while ungalled shoots produced an average of six fruits each, galled shoots did not bear any fruits. The presence of Neolithus fasciatus galls affected the host's efficiency to absorb and use the available light and functioned as a sink source for photoassimilates, water, and nutrients that would be allocated to plant development and reproduction. These data support the hypothesis that galling insects are important herbivores and their negative effects on the hosts can spread into several organs and functioning systems of the hosts.
原文链接:- NSTL
- Springer Nature
Peng, ChaoAi, WenshengQi, LianghuaTu, Jia...
12页查看更多>>摘要：Key message Chinese fir sprouting population lifespan is shortened and survivorship situation and biomass are also changed by bamboo expansion via declines in mother tree density and weakened physiological accommodation. Natural regeneration is a vital means of maintaining forest populations. Although bamboo expansion negatively affects population structures of neighboring communities, its influence on sprouting natural regeneration is still poorly understood. We compared the population structure and biomass allocation of Chinese fir regenerating sprouts in previous (CLS), middle (CPM) and late (PCM) periods of bamboo expansion. Life tables and survivorship curves were used to assess sprouting population structure and survival dynamics, and allometric analysis was conducted on biomass allocation. The results showed that bamboo expansion reduced the number and longevity (maximum age class shorted from X to VI) of the Chinese fir sprouting population and weakened its survival capacity. Survivorship curves indicated that the CLS population conformed more to a recession type (Deevey III) while CPM and PCM tended to be stable types (Deevey II). Highly mortality and survival risk in the early growing stage drove a population decrease. Meanwhile, sprouting component biomasses were decreased first and then increased by expansion effect, leaf and stem biomass had constant relationships with total biomass, and branch biomass had allometric relationships with total biomass. We considered that bamboo expansion changed sprouting population survival and growth mainly through affected Chinese fir mother tree density and growth.
原文链接:- NSTL
- Springer Nature
Shinohara, YoshinoriIida, Shin'ichiOda, TomokiKatayama, Ayumi...
11页查看更多>>摘要：Key message As the estimated parameters differed across samples, even from the same site, sample-based calibration is the recommended procedure. A trait-based approach (i.e., the use of structural parameters of the trees) would be an alternative procedure. The thermal dissipation method (TDM) is widely used for estimating transpiration by individual trees or stands. Although the importance of TDM calibration experiments is widely recognized, there is still no consensus on whether the calibration should be undertaken in practice for each species, site, or tree sample. The primary reason is that intraspecific variations in the fitting parameters have not been well examined in multiple sites. To address this, we performed TDM calibration experiments using 24 Cryptomeria japonica and Chamaecyparis obtusa samples collected from six regions in Japan and Taiwan. The sap flux density (F-d) based on the original TDM parameters was underestimated for most samples. Using a common set of parameters for 21 samples reduced the systematic underestimation. In addition, root mean square error (RMSE) was reduced by 44%. Site- and sample-based calibration reduced the RMSE by 69% and 75%, respectively. The estimated parameters for the samples varied, even among samples obtained from the same site. The recommended procedure is to obtain sample-specific parameters by performing a calibration experiment after measuring F-d under the target conditions. An alternative procedure is to use the parameters for other trees of the same species at the same site. Further, we discovered that one of the two parameters determined for each sample significantly correlated with the diameter/age ratio and height of the corresponding tree. A trait-based approach for predicting calibration parameters based on associated tree features allows the parameters to be determined without the need for calibration experiments.
原文链接:- NSTL
- Springer Nature
Gao, LiyuanAubrey, Doug P.Sun, HuizhenWang, Xingchang...
15页查看更多>>摘要：Key message Bark was the major NSC component in twigs across species. Future research should increasingly follow a bark-xylem approach for a better understanding of NSC distribution and its function in the twig. Despite extensive research on non-structural carbohydrates (NSC), the distribution of total NSC (TNC) and its primary components (sugar and starch) to the bark and xylem of twigs remains poorly understood. We determined seasonal NSC dynamics in twig bark and xylem in seven temperate tree species exhibiting different xylem anatomies and leaf habits. Seasonal trends in sugar were similar across species with concentrations peaking at least 15 days earlier in the spring for xylem than bark. However, evergreens exhibited maximum bark starch concentrations in early spring, followed by declines throughout the growing season, whereas deciduous species exhibited early spring declines in bark starch, followed by late growing season increases. Evergreens exhibited limited seasonal variation in xylem starch concentrations, whereas deciduous species exhibited variation in xylem starch concentrations that was similar to variation in bark starch. With a few exceptions, concentrations and seasonal amplitudes for sugar, starch, and TNC were generally higher in bark than xylem. Sugar concentrations were generally higher than starch, especially in the bark, which resulted in variability of TNC concentrations in bark or xylem. NSC concentrations varied significantly between xylem and the entire twig when bark was not explicitly considered. Averaged across species, sugar, starch, and TNC content in bark accounted for 66%, 54%, and 61% of total twig content, respectively, even though bark only accounted for 53% of the total twig mass. We recommend quantifying bark sugar and starch separately from xylem when determining twig NSC concentration and content.
原文链接:- NSTL
- Springer Nature
Phelan, Colleen A.Pearce, David W.Rood, Stewart B.
14页查看更多>>摘要：Key message Despite the abundant alluvial groundwater below the floodplain, riparian cottonwoods are limited by water availability during warm and dry periods, as revealed with substantially increased sap flow following flood irrigation. In dry ecoregions trees are generally restricted to floodplains along perennial streams, where river water recharges the alluvial groundwater, supplementing the sparse local precipitation. Precipitation and river flow often decline through the warm and dry summer and we hypothesized that water availability would become limiting. To test this, we measured sap flow in narrowleaf cottonwoods (Populus angustifolia) along the Oldman River in the semi-arid prairie region of western Canada. After slight rain and river recession through July and August, we provided a flood irrigation treatment to four of eight study trees, which doubled the shallow soil moisture (theta(g)). There were slight increases in dawn (psi(d)) and mid-day (psi(md)) leaf water potentials although only temporary differences between the irrigated and non-irrigated trees in psi(d) (- 0.4 vs. - 0.6 MPa), psi(md) (- 1.5 vs. - 1.7 MPa) or their difference, increment psi. The daily sap flux density (F-d) was increased by 26% over a 12-day interval after irrigation, revealing increased water use and an upward shift in the association between canopy stomatal conductance (G(S)) vs. vapour pressure deficit (D). In contrast, F-d in non-irrigated trees declined 15% with the shortening days and aging leaves. The sap flow response contrasts with prior studies, probably due to differences in irrigation volume and timing. Thus, even with abundant groundwater from river infiltration, cottonwood transpiration was limited by water availability in the dry interval of late summer. For the underlying mechanism, we introduce the River Riparian Tree Atmosphere Continuum (RRTAC), which coordinates the system hydrology and water relations.
原文链接:- NSTL
- Springer Nature
Fang, JingTian, QuanyanDu, JunChen, Longfei...
12页查看更多>>摘要：Key message Vapor pressure deficit, soil water content, and daily maximum air temperature were the most important variables to affect sap flow. Tree transpiration has a vital role in maintaining water balance in forest ecosystems, but how environmental variables affect transpiration is not clear at different altitudes in the regions of the arid mountains of China. With significant changes in water regimes in arid areas due to climate change, a greater understanding of transpiration responses to environmental variables will determine ecosystem health and management. Therefore, using the heat ratio method, sap flow in Qinghai spruce (Picea crassifolia) at different microenvironment conditions was monitored over 2 years (2016 and 2017) in the Qilian Mountains. Environmental variables were measured synchronously with sap flow. The random forests model showed that vapor pressure deficit (VPD), soil water content (SWC), and daily maximum air temperature (T-max) were the most important variables to affect sap flow across four sites and two years. These results differed within sites and years. The important variables were VPD and SWC in 2016 due to lower precipitation, and VPD and T-max in 2017. Meanwhile, the most important variables were VPD in 2016 and T-max in 2017 at the high-elevation site, while opposite at the low-elevation site. Nonlinear models showed that sap flow decreased when VPD > 0.7-1.0 kPa, and saturated when T-max > 15-20 degrees C. Sap flow was more sensitive to SWC at low than at high elevation. We concluded that VPD, SWC, and T-max controlled sap flow in Qinghai spruce at these sites. Precipitation played a key role in controlling sap flow in different years, and altitudes affected the responses of sap flow to environmental variables within years.
原文链接:- NSTL
- Springer Nature
Schroll Loss, Edenes MariaCadorin Oldoni, Tatiane LuizaDanner, Moeses AndrigoWagner Junior, Americo...
12页查看更多>>摘要：Key Message This study contributed to understand the adaptation mechanism of low chilling peach cultivars in a mild winter region according to the contents and mobilization of carbohydrates during dormancy and resumption of growth. The understanding of the physiological processes that occur in the peach tree during the dormancy period in mild winter regions (MWR) is important for the selection of new cultivars more adapted to these regions. The aim of this study was to bring more elements to build mechanistic understanding of non-structural carbohydrate (NSC) mobilization in one-year shoots of two low winter chilling peach cultivars, 'T. Beauty' and 'S. aurea', during the dormancy period and the resumption of growth in MWR and their interactions with blooming and leafing. It is hypothesized that these low chilling peach cultivars do not enter into deep endodormancy and are, therefore, able to respond to external cues of growth and development. Our results showed that the amount of starch reserve, the mobilization and the use of NSC by buds are not limiting for low chilling cultivars during dormancy period in mild winter regions.
原文链接:- NSTL
- Springer Nature
