Planting six tree species on soda-saline-alkali soil

IntroductionThereareabout2,ooo,ooohm2Ofsoda-saline-alkaIisoilinSonglunpIaininHeiIongjiang(Shen1998).ltisdistributedmainlyinZhaodong,Zhaozhou,Zhaoyuan,Anda,Daqing,Duerbuteandothercountiesandcities.FormerIy,therewerenotreesonsoda-saline-alkaIisoil.CropscannotgrowonsuchsoiIs.PIantingtreesonthesesoilsmightimproveonitsquaIity(LingetaI1982).TostudypIantingonsoda-saline-aIkalisoiIhassignificanceforestablishingprotectivepIantationsystemofgrasslandandestabIishingperfectprotec-tivepIantations…     

Filling the "vertical gap" between canopy tree species and understory shrub species:biomass allometric equations for subcanopy tree species

Subcanopy tree species are an important component of temperate secondary forests.However,their biomass equations are rarely reported,which forms a "vertical gap" between canopy tree species and understory shrub species.In this study,we destructively sampled six common subcanopy species(Syringa reticulate var.amurensis(Rupr.) Pringle,Padus racemosa(Lam.) Gilib.,Acer ginnala Maxim.,Malus baccata(Linn.) Borkh.,Rhamnus davurica Pall.,and Maackia amurensis Rupr.et Maxim.) to establish biomass equatio...     

Gmelina arborea– a viable species for smallholder tree farming in Indonesia?

Across Indonesia there are millions of hectares of degraded land in need of rehabilitation. There is interest at both the government and farmer level of converting some of these lands to more productive use, including growing trees. Smallholders often practice tree farming to generate income and traditionally cultivate a wide range of tree species in mixed agroforestry systems. Grown to satisfy both household needs and market demand, smallholder-produced timber might play a potentially important role in local markets. Tectona grandis, Swietenia macrophylla, and Paraserianthes falcataria are common smallholder timber species. Gmelina arborea (gmelina) is easy to cultivate and grow at the smallholder level. It has been widely grown in plantations in South and Southeast Asia, including Indonesia. However, gmelina is not yet a priority species with Indonesian smallholder farmers. Experience indicates that marketable small-diameter gmelina timbers can be produced in 7–10 years and that price compares well with that of Paraserianthes, the most widely grown short-rotation smallholder timber species in Indonesia. Most gmelina seed originates in Central Java, from where large quantities of seed are shipped annually to other parts of Indonesia. This seed is of uncertain quality, as seed sources are unidentified and seed collection guidelines are not used. It is recommended to establish smallholder plantations with seed of known quality. Gmelina holds promise as one component for a multi-species smallholder tree farming systems to produce short-rotation timbers for household use and local markets. Palabras clave: Agroforestales, Ensayos agrícolas, Producción de madera por pequeños propietarios, Rehabilitación de tierras, Selección de especies Resumen. A través de Indonesia, hay millones de hectáreas de terrenos degradados los cuales necesitan ser rehabilitados. Existe interés tanto al nivel gubernamental como al nivel de los agricultores, en convertir algunos de estos terrenos en sitios productivos, incluyendo la producción de árboles. Con frecuencia, para generar ingresos, los pequeños propietarios plantan árboles para cosecha y tradicionalmente cultivan un amplio rango de especies de árboles, en una variedad de sistemas agro-forestales. La madera de los pequeños propietarios, producida para satisfacer tanto las necesidades hogareñas como las demandas del mercado, puede jugar un papel potencialmente importante en los mercados locales. La Tectona grandis, la Swietenia macrophylla, y el Paraserianthes falcataria son especies comúnmente producidas por los agricultores. La Gmelina arborea (gmelina) es una especie de fácil cultivo y crecimiento al nivel de los pequeños propietarios, y se ha venido produciendo ampliamente en el sur, y el suroriente de Asia, incluyendo Indonesia. Sin embargo, la gmelina no es aún una especie de prioridad para los pequeños agricultores de Indonesia. La experiencia indica, que la madera de gmelina de pequeño diámetro puede salir al mercado en un período de 7–10 años y que el precio de esta madera es comparable con la madera del Paraserianthes, la cual es la especie de corta rotación más ampliamente utilizada por los pequeños propietarios en Indonesia. La mayoría de la semilla de la gmelina proviene de Java Central, de donde se envían anualmente grandes cantidades de semilla a otras partes de Indonesia. Esta semilla es de calidad incierta, ya que las fuentes de semilla no están identificadas y no se utilizan normas de colección de semillas. Se recomienda que las plantaciones de los pequeños propietarios sean establecidas con semilla de calidad conocida. La gmelina es prometedora como parte del sistema de cultivo de árboles de especies múltiples de los pequeños propietarios, para producir madera de corta rotación para ser utilizada localmente y enviada a mercados locales.     

Dynamics of dominant tree species in a forest ecotone on the northern slop of Changbai Mountain

The competition and dynamics of dominant trees species in the forest ecotone between the broad-leaved/Korean pine （Pinus koraiensis） mixed forest and the spruce-fir forest （also known as dark conifer forest） in Changbai Mountain, Jilin Province in Northeast China were studied by using Lotka-Volterra model, based on the data from twenty-eight sample plots with area of 20 mx90 m for each one. Results showed that under natural condition, differentiation of communities followed two directions： one would be Spruce （Picea jezoensis and few P. koraiensis） and fir （Abies nephrolepis） co-dominant conifer forest, and at the equilibrium fir was absolutely preponderant （77.1% of relative dominance （RD））; the other would be the conifer and broad-leaved mixed forest, and at equilibrium, the broad-leaved tree species was 50% of RD in the broad-leaved/Korean pine mixed forest and 66% of RD in the broad-leaved and spruce-fir mixed forest. The study demonstrated that both broad-leaved/Korean pine mixed forest and dark conifer forest were climax community, the ecotone had transitional characteristics, and the diversification of the forest communities suggested that the direction of succession was affected by local habitat.     

Is there a Nordic Model for the treatment of introduced tree species? A comparison of the use,policy, and debate concerning introduced tree species in the Nordic countries

This article compares the use, policy, and debate concerning introduced tree species in the five Nordic countries (Finland, Sweden, Norway, Denmark, and Iceland). These countries have a long common history and are culturally similar. They are often framed under the benchmark of the “Nordic Model” or even the “Nordic Forestry Model”. Therefore, we hypothesize that the Nordic countries’ treatment of introduced tree species share common aspects, and that global environmental agreements and international currents in science and policy have reinforced these similarities. The comparison shows that globalization is strong and it seems, at least at a first glimpse, that the Nordic countries follow a kind of “Nordic Model” in their approach to introduced tree species. However, the history and importance of forestry, ecological conditions, afforestation campaigns, traditions of using introduced trees, understandings, and stakeholder positions have shaped different national and even regional path dependencies and circumstances. This, in turn, has transmuted international policy-making, regulations, and discussions into different specific ways to interpret, control, and implement the use of introduced trees in practice. This article concludes that global environmental agreements and international currents in science and policy adapt to diverse national contexts.     

Quantification of tree species diversity in forest stands—model BIODIVERSS

This paper presents a method for complex evaluation and quantification of tree-layer species diversity in forest ecosystems—model BIODIVERSS. The model was constructed for the assessment of species diversity on a small-scale (forest-stand) level, but may be applied with advantage to regional and large-scale inventories. The probability of correct classification of species diversity degree is relatively high; e.g. with a sampling intensity of only 1.5%, the correctness of the classification by the model is already 90%. Model BIODIVERSS is a simple and practical tool. It can be used directly during fieldwork, since for its application only a pocket calculator is needed.     

Drought tolerance of Acacia karroo, a native tree species to South Africa, in Beijing

Acacia karroo is an indigenous, strong drought-tolerant and widely planted tree in South Africa. In order to match the plant with its adaptation to forest sites in China, it is important to know the drought-tolerance of this species under Chinese forest site conditions. Our study was carried out in cinnamon soils in Beijing and with Platycladus orientalis, the most drought-tolerant tree in Beijing, as control. Physiological parameters of young plants of the trees were measured and divided into three groups in response to soil drying. The first group included root activity, ABA content in roots and peroxidase (POD) activity in leaves. Their values changed similarly to those of P. orientalis and dramatically increased to maximum values when the soil water content (SWC) decreased from its normal level of 20% to 7.6% where the three indices decreased dramatically when SWC was reduced further from 7.6%. The second group of parameters included the contents of proline, soluble protein and malondialdehyde (MDA). Their values showed greater variation than those of P. orientalis and significantly increased when SWC decreased from 20% in response to soil drying. However, the proline and soluble protein contents fluctuated in A. karroo at a lower level than those in P. orientalis. In contrast, the content of MDA in A. karroo was much higher than that in P. orientalis which almost did not increase in the drying soil. The third group of parameters consisted of soluble sugar, superoxide dismutase (SOD) and catalase (CAT). These parameters showed greater diversity and fluctuations among the three varieties of A. karroo compared with the control in response to soil drying. These results suggest that A. karroo is characterized as a strong, drought tolerant species in most of physiological parameters but weaker than P. orientalis in membrane lipid antioxidation.     

Effect of three tree species on UV weathering of wood flour-HDPE composites

Eucalyptus urophylla, Acacia mangium, and Pinus caribaea are the primary species for the wood industry in Vietnam. Wood residues of these species were used to reinforce high-density polyethylene(HDPE) composites. The flexural or bending property, impact strength and surface color were evaluated after exposure to accelerated ultraviolet weathering up to 2000 h. The weathered surface was characterized by scanning electron microscopy(SEM) and Fourier transform infrared(FTIR) spectroscopy. The results indicate that A. mangium/HDPE composites had the lowest color change and least fading,and remained stable after 1500 h exposure. FTIR spectroscopy showed that the oxidation of the composites increased in parallel with duration of exposure by assessing the concentration of carbonyl groups on the surfaces. SEM showed that all three species reinforced composites exhibited similar severe cracks after 1000 h;however, at the end of the weathering test, E. urophylla and P. caribaea composites were more severely cracked than A. mangium composites. A. mangium also had the highest flexural strength, impact strength and crystallinity duringweathering. A. mangium is the most preferable among the three species to reinforce HDPE.     

Research advances in the study of Pistacia chinensis Bunge, a superior tree species for biomass energy

As a renewable energy, biomass energy has aroused wide attention and studies of this issue have become a hot topic throughout the world. Pistacia chinensis Bunge (Anacardiaceae) is a superior species for biomass energy with high oil content in seeds and wide geographic distribution. It is a dioeciously, deciduous arbor, flowering from March to April and bearing fruits from September to November. The classification, regional distribution and biological characteristics of P. chinensis are stated in this paper, then, research advances in the growth, breeding and physiology of this species are summarized. The problems in present studies are broached. Finally, a future direction for research is proposed.     

Taxonomic and community composition of epigeal arthropods in monoculture and mixed tree species plantations in a deciduous forest of Ghana

Tropical forests provide several ecosystem services and functions and support approximately two-thirds of the world’s biodiversity but are seriously threatened by deforestation.Approaches to counteract this menace have revolved around afforestation with several or a single tree species.We thus investigated how plantation forests with either a single or several tree species influenced arthropod taxonomic and community composition using pitfall traps to sample selected groups of epigeal arthropods...     

Patterns of tree growth in a single tree selection silver fir–European beech forest

The basal area and height growth of trees and saplings in silver fir–European beech single stem selection forest were studied with regard to their social status and crown parameters of size, coverage, shading and vitality. On 24 permanent research plots (20 m × 20 m each) all trees [diameter at breast height (dbh) ≥10 cm] and saplings (≥1.3 m tall and dbh <10 cm) were surveyed. Repeated measurements of dbh (N = 1,608) and height (N = 1,135) 10 years apart enabled the calculation of annual basal area increment (BAI) of trees and saplings, and annual height (HI) increment of saplings. To obtain the growth characteristics for individual trees and saplings, their social status and crown parameters were assessed by rank. In the multivariate general linear model for BAI, social status, crown size and crown coverage of individuals as the predictors, and dbh² as the covariate, explained 70% of total variability. Similarly, social status, crown size, crown coverage and crown shading had a significant impact on the HI of saplings, explaining 70% of total variability. Among the observed variables, social status determined according to the individual’s position in vertical stand structure was, in addition to dbh, the most important predictor for both BAI and HI. Significant differences were observed between the BAI and HI models for the main tree species (European beech and silver fir), indicating their different growth characteristics. The applied method could be used as a supplement to the more widely used approaches for studying basal area and height growth of individual trees in selection forest stands.     

Back to the roots: how do seedlings of native tree species react to the competition by exotic species?

Context

Identifying the traits of exotic species may explain their invasiveness and help control the negative impacts of these species on native ecosystems. In this study, we investigated root competition as an important driver for the competitiveness of two exotic tree species in the seedling stage.

Aims

In a pot experiment, carried out in Central Europe, we studied the effect of root competition of two exotic tree species (Prunus serotina Ehrh. and Robinia pseudoacacia L.) on biomass allocation of two native ones (Quercus robur L. and Carpinus betulus L.).

Methods

Seedlings of these species were exposed to intra- and interspecific mixtures with and without the effect of root competition. For this, belowground plastic partitions were installed in the pots.

Results

Competition intensity in the pots increased over time, irrespective of mixture type. However, this increase was much higher for the native species if mixed with the exotic species compared to monocultures or inter-native mixtures. In addition to ontogeny, competition affected biomass allocation patterns. Under root competition by the exotic species, the native species preferentially allocated their biomass to the roots. A higher allocation to the roots was mainly achieved at the expense of leaf and branch biomass.

Conclusion

Root competition of P. serotina and R. pseudoacacia may be a reason for the lack of Q. robur and C. betulus in the seedling stage in natural environments where all four species occur.     

Response of seedlings of different tree species to elevated C02 in Changbai Mountain

Eco-physiological responses of seedlings of eight species,Pinus koraiensis, Picea koraiensis, Larix olgensis, Populus ussuriensis, Betula platyphylla, Tilia amurensis, Traxinus mandshurica andAcer mono from broadleaved/Korean pine forest, to elevated CO₂ were studied by using open-top chambers under natural sunlight in Changbai Mountain, China in two growing seasons (1998–1999). Two concentrations of CO₂ were designed: elevated CO₂ (700 μmol·mol⁻¹) and ambient CO₂ (400 μmol·mol⁻¹). The study results showed that the height growth of the tree seedlings grown at elevated CO₂ increased by about 10%–40% compared to those grown at ambient CO₂. And the water using efficiency of seedlings also followed the same tendency. However, the responses of seedlings in transpiration and chlorophyll content to elevated CO₂ varied with tree species. The broad-leaf tree species were more sensitive to the elevated CO₂ than conifer tree species. All seedlings showed a photosynthetic acclimation to long-term elevated CO₂. Foundation item: The project was supported by National Key Basic Development of China (G1999043400) and the grant KZCX 406-4, KZCX1 SW-01 of the Chinese Academy of Sciences Biography: WANG Miao (1964-), maie, associate professor in Institute of applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P. R. China. Responsible editor: Song Funan     

Does tree species composition control soil organic carbon pools in Mediterranean mountain forests?

We compared soil organic carbon (SOC) stocks and stability under two widely distributed tree species in the Mediterranean region: Scots pine (Pinus sylvestris L.) and Pyrenean oak (Quercus pyrenaica Willd.) at their ecotone. We hypothesised that soils under Scots pine store more SOC and that tree species composition controls the amount and biochemical composition of organic matter inputs, but does not influence physico-chemical stabilization of SOC. At three locations in Central Spain, we assessed SOC stocks in the forest floor and down to 50 cm in the mineral in pure and mixed stands of Pyrenean oak and Scots pine, as well as litterfall inputs over approximately 3 years at two sites. The relative SOC stability in the topsoil (0-10 cm) was determined through size-fractionation (53 μm) into mineral-associated and particulate organic matter and through KMnO₄-reactive C and soil C:N ratio.Scots pine soils stored 95-140 Mg ha⁻¹ of C (forest floor plus 50 cm mineral soil), roughly the double than Pyrenean oak soils (40-80 Mg ha⁻¹ of C), with stocks closely correlated to litterfall rates. Differences were most pronounced in the forest floor and uppermost 10 cm of the mineral soil, but remained evident in the deeper layers. Biochemical indicators of soil organic matter suggested that biochemical recalcitrance of soil organic matter was higher under pine than under oak, contributing as well to a greater SOC storage under pine. Differences in SOC stocks between tree species were mainly due to the particulate organic matter (not associated to mineral particles). Forest conversion from Pyrenean oak to Scots pine may contribute to enhance soil C sequestration, but only in form of mineral-unprotected soil organic matter.     

Regeneration ecology and population status of a critically endangered and endemic tree species （Ilex khasiana Purk.） in north-eastern India

Detailed studies on population structure and regeneration ecology of Ilex khasiana were carried out at five representative natural populations i.e. Mylliem (Population - I), Upper Shillong (Population - II), Shillong Peak (Population - III), Laitkor (Population - IV) and Nongpiyur (Population - V) to probe into the responsible affecting factors for its population structure and regeneration ability in these populations. Experimental observation under three controlled light conditions (full sunlight (100%), intermediate sunlight (50%) and low sunlight (30%)) showed that the growth status and survival rates of seedlings under intermediate and low light were better than those under the high light condition. The density-diameter distribution in population of adult trees (≥5cm dbh) exhibited a typical character of a regenerating population. A higher seedling mortality rate in natural populations of I. khasiana was most probably due to increase in light intensity following vegetation destruction and other anthropogenic disturbances that cause opening of forest canopy. The findings of the present study would be of immense value in formulating appropriate conservation measures for the species.     

Swedish private forest owners’ perceptions and intentions with respect to adopting exotic tree species

Swedish forest growth can be increased through intensive forestry practices, enabling an increased use of forest biomass for climate-change mitigation. However, the diffusion of such practices depends on the forest owners’ adoption of them. We study Swedish private forest owners’ perceptions and intentions with respect to increasing forest growth by adopting exotic tree species. The results of a mail-in questionnaire survey show that although a majority of forest owners desire increasing forest growth, most owners have only a basic understanding of exotic tree species and a smaller proportion is interested in adopting them. The intention to adopt exotics seems to depend on the perceived performance of the species with respect to the economic aspects of forest management rather than on environmental or recreational concerns. Whereas a knowledge gap among the private forest owners regarding how to increase forest growth is implied, forest owners with higher self-rated knowledge of forestry and exotics have stronger intentions to adopt such species.     

Light intensity and hydrogel soil amendment differentially affect growth and photosynthesis of successional tree species

Global climate changes have increased temperatures,radiation indexes,and consequently,irregularities in rainfall in mainly tropical countries,considerably hindering plant establishment in recovering degraded areas.The objective of this study was to evaluate the growth and physiological characteristics of one species of each successional group:pioneer,secondary,and climax when subjected to different light intensities and hydrogel as a soil conditioner during rainy and dry periods.The experiment w...