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1.
Horse chestnut (Aesculus hippocastanum L.) is a common urban tree species in Ljubljana, the capital of Slovenia. This area is forecast to experience a general reduction in precipitation and an increase in temperature, which increases water demand in plants. Because A. hippocastanum is known for its drought vulnerability, the question of the future suitability of this urban tree species in Ljubljana has arisen. To investigate how climate has influenced A. hippocastanum radial growth and how trees responded to extreme climatic events, standardized precipitation-evapotranspiration index (SPEI) was used as a proxy for water demand. Climatic signal and its stability through time were calculated using Pearson’s correlation coefficient. Additionally, to investigate whether the trees had a common response to extreme climatic events, pointer years were calculated using Cropper values. We sampled 19 trees that were growing in Tivoli Park in Ljubljana. After successful cross-dating of 15 trees, the ring count showed that the trees had up to 201 tree-rings and had 130 on average. Climate-tree growth analysis showed that in July, 3-month SPEI had the strongest influence on radial growth, but its influence on radial growth decreased over time, possibly due to the die-off process of trees. The narrowest tree-rings were a result of unusually dry periods at the time of cambium activity and/or new cell growth. With the forecast of longer, more frequent summer drought periods in Ljubljana, soil moisture stress will increase, and as a result, a decrease in radial tree growth of A. hippocastanum trees from Tivoli Park is expected. 相似文献
2.
Establishment is a key concept in urban forestry but it is currently inconsistently defined and measured. Thus, several different methods are being used to determine establishment success but their consequences and applications are rarely discussed. With this paper we would like to stimulate an increased discussion regarding these concepts both in relation to a theoretical definition but also to their practical use. The problem was approached through an experiment using sweet cherry (Prunus avium L.) and northern red oak (Quercus rubra L.) trees and the most common methods used for determination of establishment success. The trees were studied during the first three years after transplant and the association between the different measuring methods was examined. A Principal Component Analysis showed that terminal and lateral shoot length were strongly correlated, and that midday- and pre-dawn shoot water potential, and stomatal conductance were strongly correlated. We developed an index for nightly recovery of water status, which showed that terminal shoot growth was not related to nightly recovery until the third year after transplanting. Our results suggest that successful tree establishment is determined differently depending on which method is used for determination but that the differences might decrease with time. The lack of a firm definition of the term establishment may complicate communication, both within the scientific community and in practice. 相似文献
3.
Trees with root systems established well below grade due to deep planting or soil disturbance are common in urban landscapes, yet the long term effects of buried trunks and subsequent remediation strategies, such as root collar excavation are poorly documented. We evaluated the consequences of deep planting over a 10-year period on tree growth and stability, with and without root collar excavation, for red maple [Acer rubrum L. Red Sunset® (‘Franksred’)] and Northern red oak (Quercus rubra L.) planted at grade or 30-cm below grade. Sleeves to prevent soil-trunk contact were installed around trunks on a subset of deep trees. Root collar excavations were made during the 6th growing season for both species and trees were grown for an additional 4 and 3 growing seasons for red maples and Northern red oaks, respectively. Within two weeks of root collar excavations, pulling tests compared the effect of treatments on stability of red maples. Deep planting generally slowed growth of red maple but had no clear effect on Northern red oak. Root collar excavation had no lasting effect on growth of either species. Approximately 55% of deep red maples and 33% of deep Northern red oaks had roots crossing and in intimate contact with buried trunks, suggesting a potential for future girdling roots. Approximately 25% of deep maples had substantial adventitious rooting. All deep Northern red oaks had new roots emerging just above the first original structural roots but none were clearly adventitious. Trunk sleeves had no effect on growth for either species. Neither deep planting nor root collar excavation resulted in a loss of tree stability compared to trees planted at grade, although failure patterns varied among treatments. Overall, the biggest long term concern for deep-planted trees is the potential for girdling root formation. 相似文献
4.
Weed control is often crucial for successful tree establishment. Removal or suppression of competitive vegetation has most often been done by either mowing or the use of herbicides. The Institute of Forestry and Game Management in Flanders (Belgium) has been conducting a three-year experiment (as part of a five-year programme) to assess 18 treatments for newly planted deciduous trees established on ex-agricultural sites. On grass-covered sites mortality of English oak(Quercus roburL.) decreased significantly when mulch sheets were applied. Mulch sheets increased growth of all species in a pasture. An unequivocal relation was found between the diameter of the weed-free area around the tree and the Relative Growth Rate of Common alder (Alnus glutinosa (L.) Gaertn.). Rigid sheets, such as those made of polypropylene could severely damage the trunk of the trees. Bark mulch decreased growth of English oak in the first year, but increased it significantly after 3 years. The application of bark mulch was time-consuming compared to the other treatments. Usage of herbicides on a clay soil was nefarious to both survival and growth of the treated trees. Mowing, often used by the Flemish Forestry Service, had no significant effect on the growth of the trees. 相似文献
5.
The knowledge of the rate at which trees grow in urban areas is an important aspect to consider as it can influence our quantification and valuation of the ecosystem services provided by an urban forest. This study investigates growth variations in diameter and height for four common urban tree species (Acer pseudoplatanus, Betula pendula, Fraxinus excelsior and Quercus robur) across five cities in Great Britain (GB) and how the typical radial growth of two of those species (F. excelsior and Q. robur) changes with climate. Dendrochronology was used to identify tree age and changes in ring width and diameter at breast height (DBH) and tree height were measured in-situ at the time of coring. Results indicate a substantial variation in the mean annual growth rates and the relationships between DBH and age or height and age of each species across different cities. However, the multiple factors affecting tree growth seem to influence different species in different ways, with for example A. pseudoplatanus trees showing overall the fastest growth in Peterborough but B. pendula ones showing the slowest. Precipitation and temperature had an effect on radial growth of F. excelsior and Q. robur trees in GB, but the strength and direction of influence varied with time of year, species and city. In particular, low precipitation at the start or during the growing season was found to be a significant factor limiting radial growth. A trend towards a reduction in ring width increment was therefore identified in hot and dry years, primarily in south-eastern cities but in other cities too. This highlights the risk that a changing climate may have on the growth and, consequently, on the ecosystem service provision of healthy urban trees. 相似文献
6.
Increasing tree species diversity has become a key underpinning for communities to improve resilience of urban and community forests. Increasingly, urban forestry researchers are examining physiological traits to aid in selecting trees for urban sites. Knowledge of physiological responses also has implications for understanding species’ resilience to increased stresses associated with climate change. Here, we compare growth, leaf SPAD chlorophyll index, water relations, and gas exchange of seven genotypes of shade trees planted in two locations in downtown Detroit, MI, USA. Genotypes included Redpointe® maple (Acer rubrum ‘Frank Jr.’), Flashfire® maple (Acer saccharum ‘JFS-Caddo2′), Pacific Sunset® maple (Acer truncatum x platanoides ‘Warrenred’), Emerald City® tulip tree (Liriodendron tulipifera ‘JFS-Oz’), Chanticleer® pear (Pyrus calleryana ‘Glen’s Form’), swamp white oak (Quercus bicolor), and Emerald Sunshine® elm (Ulmus propinqua ‘JFS-Bieberich’). Trees were planted in either Lafayette Plaisance Park (Park), a large urban greenspace, or on the median of St. Aubin Avenue (Median), a nearby major thoroughfare. Tree height growth and leaf SPAD index were higher for trees planted in the Park location than on the Median. However, genotypic variation was larger than the effects of location or the interaction of Genotype × Location for most traits. Across measurement dates, midday leaf water potential was lowest for Pyrus trees and highest for Ulmus and Liriodendron trees. Pyrus and Quercus trees had relatively high rates of net photosynthesis (A) and stomatal conductance (gs) while Liriodendron, Acer saccharum, and Ulmus trees had low rates of A and gs. Liriodendron trees closed their stomata rapidly as leaf water potential (Ψw) declined (isohydric response), while Pyrus and Quercus trees maintained gs across a range of leaf Ψw (anisohydric response). Liriodendron trees also had the highest relative growth rates, suggesting that drought stress avoidance through isohydry is a viable drought tolerance mechanism in urban trees. 相似文献
7.
《Scientia Horticulturae》2005,103(4):503-507
Microcuttings with apical and nodal buds from common oak (Quercus robur L.) and Turkey oak (Quercus cerris L.) in vitro clones were encapsulated into an alginate matrix. Apical segments of common oak showed significantly greater in vitro regeneration potential as compared with the nodal ones. Encapsulated Turkey oak nodal segments demonstrated successful regeneration after different periods (2–6 weeks) of cold storage (4 °C), showing no significant deviation from the regenerative frequency of non-cold-treated segments. 相似文献
8.
Arborists install cables to support co-dominant stems. The adaptive growth hypothesis predicts that doing so will alter radial increments in the stems because their motion will have been restricted. To facilitate the wind-induced motion of cabled stems, cables made of more extensible material have been suggested as an alternative to systems made of steel. Cables made of steel and polypropylene were installed in red oaks (Quercus rubra L.). Trees were harvested after five years and annual radial increment was measured for the previous sixteen years in four directions (incident with and perpendicular to the direction of the cable) on five discs removed from two co-dominant stems that were cabled in each tree. Annual radial increment did not change in response to the installation of cables with one exception: in the three years following installation, it was greater incident with the cable on two discs immediately proximal and distal to the eyebolt in each co-dominant stem to which steel cables were attached. The exception appears to be due to the formation of wound wood. The results contradict the adaptive growth hypothesis, but this was likely due to cables not restricting wind-induced motion to the extent achieved in previous studies. 相似文献
9.
The determination of tree age is an important issue for urban green planning, forestry and dendrology; finding non-destructive and quasi-non-destructive methods for this purpose is of great theoretical and practical importance. The resistance drilling method is quasi-non-destructive because the average diameter of an opening that remains after drilling does not exceed 3 mm. Do electrically recording resistance drills allow precise assessment of tree age? The aim of this study is to assess the accuracy of determining the number of tree rings based on an examination of this special kind of drilling resistance profiles for three tree species, the pine Pinus sylvestris L., the oak Quercus robur L., and the birch Betula pendula ROTH. In 2015 and 2016, 15 pine trees, 15 oak trees, and 15 birch trees were randomly selected. For each studied tree, a measurement was conducted using the electrically recording resistance drill IML-Resi E400 with a flat-tipped 1.5/3 mm steel needle (research sample), and an increment core was taken (reference sample). The drill used was not a real Resistograph®. The analysis of the E400-profiles underestimated the number of tree rings; the mean bias error (MBE) values were –6.5, –2.5, and –6.0 years for pine, oak, and birch, respectively. The proportion of investigated trees with less than five years difference between the research and reference samples varied from 38.4 (birch) to 66.7 (oak) percent. The accuracy of tree age determination was lowest for birch and highest for oak. The binomial generalised linear model (GLM) revealed that the most accurate tree age assessments were obtained from tree rings wider than 2 mm. The measurements clearly showed that the electrically recording resistance drill IML-Resi E400 enables a quick, although approximate, tree age assessment. Future research should concentrate on electronically regulating and recording drills, providing a higher spatial and signal resolution, and a stronger correlation to wood density. 相似文献
10.
In recent years, Central European forests and trees have been severely suffered from drought events in the growing season. To examine the tree growth response to drought stress, measurements of annual shoot lengths (ASL) of various tree species with distinct ages and habitats were taken in southeast Germany. The index of relative ASL increase (RAI), which is a standardized ASL increase, was calculated to indicate the growth rate of various tree species between the non-drought (2015–2017) and the drought period (2018–2020). The results showed the ASLs of most early-young trees (< 10 years) significantly showed a decreasing tendency in the drought period, whereas the middle-young (11–15 years) and late-young trees (> 16 years) presented a relatively stable trend. The ring-porous species with anisohydric behavior were likely to have higher RAIs associated with higher drought tolerance than diffuse-porous species with isohydric behavior. However, tree growth rate did not correlate with drought tolerance (resistance) of tree species indicated by leaf turgor loss point (Ψtlp, MPa). Therefore, this study suggested parameters, such as growth rate, age phases, and microhabitats, should be considered to predict tree species’ drought tolerance other than Ψtlp. Finally, we emphasized tree shoot growth responses to drought were affected by multiple internal and external factors, and strongly depended on species- and site-specific characteristics, such as age phases, xylem structure, hydraulic strategy, microhabitat, grafting effect, and competition. ASL measurement can be recommended to be an easy, fast, and effective method to detect tree growth rate and response to environmental stress. 相似文献
11.
以塞罕坝林区天然华北落叶松（Larix principis-rupprechtii）林为研究对象,应用树木年轮学方法,分析快速升温前后华北落叶松年轮宽度指数与气象因子的相关性,探究气候变化对该区华北落叶松径向生长的影响。结果显示,塞罕坝地区于1987年发生升温突变;1950-1987年时段,华北落叶松径向生长对温度正响应,与5-6月均最高温达到显著关系;1987-2018年时段,华北落叶松表现出“响应分异现象”,与5-7月均最高温达到显著负相关,与8-9月均最高温由不显著正相关转变为极显著负相关。快速升温后,华北落叶松径向生长与7月降水呈显著正相关。升温突变后,华北落叶松径向生长开始受到生长季前期和生长季干旱胁迫。 相似文献
12.
Francesca Ugolini Roberto Tognetti Antonio Raschi Laura Bacci 《Urban Forestry & Urban Greening》2013,12(4):576-584
In recent years the use of plants as bioaccumulators or bioindicators has increased because enable the prediction of pollution for monitoring purposes, even in urban environments where traffic is a major source of heavy metals pollution. In this study we hypothesized holm oak (Quercus ilex L.) a valid trapping species for heavy metals. We also hypothesized that metals capture capacity by deposition on the crown is connected to the surrounding environmental characteristics and the distance of trees from the source of pollution. The study was conducted in the city of Florence. Holm oaks were selected in different sites near to heavy traffic roads. Concentrations of Zn, Pb, Cd, Cu, Fe, Mn, Cr, and Ba were analyzed through two methods: leaf washing with distilled water and leaf unwashing.One-year-old leaves (new leaves) were also compared with previous-year leaves (old leaves). Our results demonstrated the good capacity of this species to capture heavy metals (Pb, Fe, Mn, Cr, and Ba), particularly due to the presence of old leaves, which enhance the crown deposition surface. Washing was effective and it allowed testing the behaviour with regard to microelements: new leaves showed high Cu concentration, while old leaves had high Pb concentration. The dispersion of metals through the atmosphere was assessed through regression analysis, in two comparable gardens: leaves at farther distance from the traffic were richer in Zn, Pb, Mn, and Ba. The physical context of the surrounding environment was probably altering the distribution of heavy metals as barriers to dispersion, which can reach tens of metres from the source of pollution. Therefore, this work suggests that wind modelling and trees distribution and characteristics should be taken into consideration to evaluate the pollutants dispersion, especially for planning of recreational urban green areas. 相似文献
13.
The main objective of this research was to investigate climate-growth relationships and if climate is a possible cause of oak decline in a very representative peri-urban forest in the Mediterranean area. The dendrochronological behaviours of healthy trees and declining trees were compared according to compromised vitality as assessed by crown defoliation. The analysed parameters were ring and latewood widths. The results showed that ring widths and latewood depended directly on spring precipitation (April-May-June) and, inversely, on spring-summer temperature (April-May-June-July). The growth histories of healthy and declining deciduous oaks in Castelporziano, as evaluated by their crown vitality, were very similar. The onset of decline dates back to the middle of the 1940s, and a further irreversible growth depression was based on the increase in temperature in the 1980s. This climatic change is reflected roughly 13 years later in declining trees, 17 years later in the healthy ones, in a strong growth depression that appears very exacerbated by the recurrent warm extreme events after the 2000s. Latewood in our study did not add more to the total ring-width measurements, potentially because of a high state of tree suffering. Declining trees were in general older than healthy ones, but in this study, the difference in age was not different from a statistical point of view. 相似文献
14.
Urban stormwater is a major contributor to surface water degradation in the United States, prompting cities to invest in ways to naturally capture, store, and slowly release runoff through green infrastructure (GI). An often overlooked, yet integral, component of GI is urban tree canopy, which functions as GI through the process of rainfall interception (i.e., rainfall captured and stored within the canopy prior to returning to the atmosphere via evaporation). Nine trees from three native species commonly found in urban areas in the southeastern United States were studied in three parks in Knoxville, TN, USA to quantify interception. Throughfall (rainfall that passes through the canopy) and stemflow (rainfall that travels down the trunk) data were collected with continuous measurements by a network of automatic rain gauges positioned underneath each tree canopy. Data were collected from January 2018 to May 2019 which resulted in 98 storm events collected for each red maple (Acer rubrum) and willow oak (Quercus phellos), and 97 storm events collected for each white pine (Pinus strobus). Annually, red maples, white pines, and willow oaks intercepted 24.4%, 52.4%, and 33.2% of gross throughfall, respectively. Seasonally, white pines performed the most consistently with interception varying only from 49.2% to 57.0% between seasons compared to an interception range of 13.2–39.7% and 17.5–54.2% for red maples and willow oaks, respectively. Results demonstrated the effect of event duration, rainfall intensity, and seasonality on the interception potential of each species. Overall, these observations are a step toward allowing the storage capacity of urban trees to be properly credited as part of efforts to reduce stormwater runoff. 相似文献
15.
Peter A. Roussos Nikoleta-Kleio Denaxa Theodoros Damvakaris Vassilios Stournaras Ioannis Argyrokastritis 《Scientia Horticulturae》2010
Two years old self-rooted Koroneiki olive trees (Olea europaea L.) were subjected to two irrigation regimes, i.e. the fully irrigated and the severely water stressed trees, while they were treated with three alleviating products of different mode of action. The products used were the osmolyte glycine betaine, the antioxidant Ambiol and the heat and irradiance reflecting kaolin clay particles. The effects of product application and water regime on leaf characteristics, shoot and root growth, photosynthesis, leaf compatible solids (carbohydrates) concentration and yield were evaluated. All products applied, exhibited significant alleviating action, based on the relative alleviation index. Irrigated trees exhibited greater growth than drought stressed ones, while the ameliorating products maintained the water content of the leaves under drought conditions and resulted in lower leaf tissue density. On the other hand carbon assimilation rate, stomatal conductance and intrinsic water use efficiency were significantly reduced under drought stress, while the opposite stood for intercellular CO2. Drought stress resulted in elevated sucrose leaf concentration, while the application of Ambiol increased stachyose concentration and that of glycine betaine did the same with the mannitol concentration. Among the alleviating products tested in this experiment Ambiol and glycine betaine had a significant positive effect on leaf water content, photosynthesis and yield under both drought and well irrigated conditions. 相似文献
16.
Urban forests are environmentally, climatically, socially and economically important. An understanding of the response of urban trees to future climate change is crucial to the maintenance of urban forests and the ecosystem services they support. We conducted a controlled environment pot-experiment on four-year-old Mediterranean oak species: the evergreen Quercus ilex and the deciduous Quercus cerris, to investigate the combined impact of elevated CO2 and temperature on growth and leaf physiology to levels predicted for 2050 in urban areas of central Italy. Quercus cerris initially increased net-photosynthesis (PN) under elevated 2050 conditions (EC) compared to present ambient conditions (AC), before PN declined, possibly indicative of down-regulation of photosynthetic physiology. Quercus ilex PN was not influenced by EC throughout the 70 days duration of the study. Levels of PN and stomatal conductance (Gs) were generally lower in Q. ilex than Q. cerris. Quercus ilex also reduced Gs during growth at EC. This reduced transpirative water-loss caused a significant increase in the water use efficiency (WUE) of Q. ilex. This reduction in Gs may have been associated with the observed reduction in stomatal density in Q. ilex grown under EC, while the number of stomata on leaves developed under the experimental conditions were unaffected by the EC treatment in Q. cerris. Over the course of the experiment, above (stem dry weight: SDW) and below-ground biomass (root dry weight: RDW) and foliar starch increased in Q. cerris (in both EC and AC equally) but not Q. ilex. Chlorophyll a fluorescence (ChlF); Prompt Fluorescence (PF), Delayed Fluorescence (DF) and Modulated Reflectance (MR) also indicated that a greater resilience of photochemistry to growth under EC was more apparent in Q. ilex than Q. cerris. In particular, the reduction of the quantum yield efficiency (FV/FM) in Q. ilex may also be considered functional to maintain constant PN levels in elevated temperature and [CO2]. The results of this study suggest that Q. ilex exhibits greater plasticity and adaptation to EC, and may therefore perform more favourably under future 2050 climatic conditions. 相似文献
17.
Urban forests have many positive effects on human health and recreation. However, urban areas can create stressful environments for native trees, leading to increased mortality and an altered ecosystem. Here, we compare growth variability and the climate response from old (>200 years) L. tulipifera growing in an urban forest in Bloomington, IN to surrounding non-urban sites in southern Indiana using dendrochronological techniques. We found that L. tulipifera growing in the urban forest responded similarly with small differences to climate compared to the non-urban sites. Radial growth from urban L. tulipifera had statistically similar correlation values with temperature, soil moisture, and precipitation compared to the trees in non-urban forests. Growth variability between the urban and non-urban L. tulipifera trees showed good agreement through time with the exception of the 20th century, where the urban forest experienced a stand-wide release from competition. Our results indicate that some urban forests may function similarly to non-urban forests from an ecological perspective. These findings suggest management practices from non-urban old-growth forest could be useful for management of rare urban old-growth forests. 相似文献
18.
Trunks of 8-year-old vigorous ‘Fuyu’ persimmon (Diospyros kaki Thunb.) were girdled to a 1 cm width on April 20 and June 10 2004. Tree growth and fruit characteristics were monitored for two years, with special emphasis on the carry-over effect in 2005. Girdling reduced trunk and shoot growth especially of April-girdled trees over two consecutive years. However, the most significant effect of girdling was in the occurrence of water sprouts: a control tree had 29.5 in 2004 and 27.3 in 2005, whereas the April-girdled trees had only 0.3 and 5.3, respectively. Girdling increased fruit set by nearly 50% and enhanced fruit colour in 2004 only. Girdling date did not significantly affect fruit size and soluble solids for two years. Fruit flesh of girdled trees in 2004, especially in the April-girdled trees, had lower N and P concentrations. The levels of starch, soluble sugars, and inorganic elements in flower-bearing distal buds measured just before new growth in 2005 were not significantly altered by the girdling in 2004. 相似文献
19.
Urban environments are often characterized by extensive paved surfaces, exacerbating the urban heat island effect. At the same time, limited root space due to underground infrastructure poses a challenge for planting new trees in these areas. Trees in planters have emerged as popular design elements, offering innovative and sustainable greening solutions, particularly in urban environments with limited rooting space. However, growing conditions in planters may strongly impact tree growth and the provision of environmental ecosystem services (ES). In this 3-year study, we analyzed tree growth and ecosystem services (cooling by shading, CO2-fixation) of London plane (Platanus x hispanica Münchh.) and small-leaved lime (Tilia cordata Mill.) in four planting treatments: in-ground (G), planters in the ground (PG), non-insulated plastic planters (P), and insulated planters (PI). We also recorded soil temperature throughout the experiment and implemented soil drought conditions by reducing soil irrigation for half of the trees after one year. Our findings revealed higher thermal fluctuations in soil temperature within non-insulated plastic planters (P), reaching a maximum of 45 °C, surpassing the critical temperature threshold for plant growth (>38 °C). In contrast, insulated planters (PI) effectively mitigated soil temperatures, staying below 33.8 °C. When planted in the ground (G), P. x hispanica exhibited a significantly higher stem diameter increment (52–66%) compared to other planting treatments, aligning with the provision of ecosystem services. However, T. cordata trees showed a more moderate response to planting treatments in terms of growth and ecosystem service provision. Furthermore, the implementation of soil drought conditions resulted in a reduction of up to 34% in stem diameter increment for P. x hispanica and up to 25% for T. cordata. Our results underscore the necessity of tree species-specific knowledge about growth responses to different planting treatments for effective urban planning perspectives, as the provision of ecosystem services may be influenced differently. 相似文献
20.
Slow-release fertilizer rates (0, 1.1 and 4.5 kg/m3 of 14 N-6 P-11.6 K Osmocote) and isolates of the ectomycorrhizal fungus Pisolithus tinctorius (Pers.) Coker and Couch affected growth and mycorrhizal development on pin oak (Quercus palustris Meunchh.) seedlings. Mycorrhizae developed on all inoculated seedlings after 8 weeks regardless of fertility regime. Through the first 14 weeks, the best mycorrhizal development occurred on all inoculated seedlings fertilized at the lower fertilizer rate. The higher fertilizer rate delayed mycorrhizal development. However, after 18 weeks there were no significant differences in mycorrhizae on inoculated seedlings receiving fertilizer. Inoculated, non-fertilized seedlings had significantly less mycorrhizae than fertilized seedlings throughout the experiment. Only one isolate increased seedling growth, and only at the higher fertilizer rate. No differences in plant height were found among non-inoculated control and inoculated seedlings at the low fertilizer rate. 相似文献