Effect of inundation duration on <Emphasis Type="Italic">Salix gracilistyla</Emphasis> density and size on a gravel bar

To clarify the effects of inundation on the establishment of Salix gracilistyla trees, the relationship between total inundation duration and the distribution and size of trees was examined on a gravel bar along the Miya River in central Japan. The density of S. gracilistyla was low at both low and high elevations on the gravel bar, but high at middle elevations. The density increased with up to 165 days of inundation and declined gradually with more than 165 days of inundation. Density had a negative effect on crown area, whereas inundation duration had a positive effect. At lower elevations, growth limitation of S. gracilistyla is mainly caused by inundation stress, whereas at higher elevations it seems to be primarily due to drought stress, although it depends on the total duration of inundation in a year (TDIY). Consequently, the density is highest at middle elevations where trees do not become too large. These results suggest that inundation duration is one factor determining the density of S. gracilistyla trees, which in turn affects the size of each tree.     

Antioxidant and cytotoxic activities of naphthalene derivatives from <Emphasis Type=Italic>Diospyros kaki</Emphasis>

4,8-Dihydroxy-5-methoxy-2-naphthaldehyde (Compound I) was isolated from blackened heartwood of Diospyros kaki and was methylated with diazomethane. Antioxidant and cytotoxic activities of Compound I and two methylated derivatives [4-hydroxy-5,8-dimethoxy-2-(2-oxopropyl)-naphthalene (D-1) and 2-glycidyl-4-hydroxy-5,8-dimethoxy naphthalene (D-2)] were evaluated. Compound I showed higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and reducing power than D-1 and D-2. However, D-1 and D-2 exhibited slightly stronger 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)⁺ (ABTS⁺) radical scavenging activity than Compound I. Compound I also exhibited stronger cytotoxic activity than D-1 and D-2 against the growth of HT-29 colon cancer cells. The results supported the hypothesis that methylation of naphthalene derivatives slightly increased ABTS⁺ radical scavenging activity, but significantly decreased DPPH radical scavenging activity, reducing power, and cytotoxic activity.     

Intra-specific variation for response to salt and waterlogging in <Emphasis Type=Italic>Acacia ampliceps</Emphasis> Maslin seedlings

Salinity is a major form of land degradation worldwide, with seasonal or temporary waterlogging often being an associated issue. Acacia ampliceps is a highly salt-tolerant small tree, naturally-occurring in north-western Australia, which produces abundant biomass with potential for fuelwood and fodder. We investigated the extent of variation amongst provenances and families of A. ampliceps for seedling response to salt and waterlogging. Seven-week old seedlings from 27 families (seven provenances, grouped into two regions), were treated in sand-filled pots in a glasshouse with either mixed salt (S) solutions (150 mol m⁻³ for 14 days, 300 mol m⁻³ for 33 days), waterlogging (W) or combined salt (S) and waterlogging (SW). Only 3% of seedlings died, mostly from the combined salt × waterlogging treatment. Seedlings from the Kimberley region had significantly greater height and shoot biomass than those from the Pilbara. Within these regions, Wave Hill (seedlot 14631) and Halls Creek (15738) provenances had the best growth. Height growth was reduced similarly for S- and W-treated plants, whereas that of SW-treated plants was reduced much more. Salt and waterlogging caused shoot dry weight reduction at harvest of 41 and 46%, respectively, with a slight interaction between salt and waterlogging; SW treated plants were most affected. Generally there were relatively small differences in the growth response of provenances and families to salt, but larger (often highly significant) variation in response to waterlogging. Genotypic variation for shoot and phyllode water content and phyllode number in response to salt and waterlogging was generally small. The good agreement found at the provenance level between seedling growth in this experiment and growth of young trees on saline land in a trial in Pakistan suggests that glasshouse screening may be a useful means for selecting potential provenances for field evaluation.     

Phenotypic variation among five provenances of <Emphasis Type=Italic>Populus simonii</Emphasis> in northern China

We investigated phenotypic variation of Populus simonii from five provenances in northern China. Our results show that significant differences exist between plants of different provenances in morphological and physiological traits, except for leaf-stalk length and the number of leaf margins. The coefficient of variation for all traits ranges from 14.77% to 81.49%. The mean phenotypic coefficient of differentiation (V ST ) is 47.1%, which means that the variation within provenances is the major source for phenotypic variation in P. simonii. Given our cluster analysis of provenances based on an average linkage computing method, the five provenances of P. simonii investigated could be divided into three groups. Our results provide a theoretical basis for genetic resource conservation and provenance selection of natural P. simonii in northern China.     

Emissions of volatile organic compounds from heated needles and twigs of <Emphasis Type=Italic>Pinus pumila</Emphasis>

A study was conducted to explore the mechanism that emissions of volatile organic compounds(VOC) from heated needles and twigs(200°C,within 15 min) of Pinus pumila affect fire behaviours using the technology of Thermal Desorption-Gas Chromatography-Mass Spectrometry(TD-GC-MS).The results indicated that the main components of VOC from heated needles and twigs are terpenoids.Most of these terpenoids are monoterpenes.Terpenoids account for 72.93% for the needles and 92.40% for the twigs of the total VOC,and their emission ratios are 61.200 μg·g-1 and 217.060 μg·g-1 respectively.Heated twigs can emit more terpenoids than heated needles because twigs had more volatile oils than needles.In actual fires,these large amounts of terpenoid emissions,especially the monoterpene emissions,have strong effects on fire behaviors that are not only in the initial stage but also in the fast propagation stage of fires.These flammable gases are capable of causing violent combustion and creating crown fires.In addition,if these gases accumulate in an uneven geographical area,there will be a possible for eruptive fires and/or fires flashover to occur.     

Survival and growth of drought hardened <Emphasis Type="Italic">Eucalyptus pilularis</Emphasis> Sm. seedlings and vegetative cuttings

Forestry requires low mortality of transplanted seedlings. Mortality shortly after planting is often associated with inadequate hydration of transplants. Seedlings can be hardened to the drought conditions they may experience after transplanting by exposing them to controlled drought conditions in the nursery. Eucalyptus pilularis Sm. seedlings were drought hardened by providing nil (severe treatment) or half (mild treatment) the daily irrigation routinely received (control treatment) for up to two non-consecutive days per week during the last 4 weeks of growth in the nursery. Drought hardening reduced stem diameter, seedling leaf area, leaf area per root biomass and seedling quality measured by the Dickson quality index, but increased root:shoot ratio. Hardened seedlings had lower stomatal conductance and leaf water potential on the days they received less irrigation that the control treatment. Hardened seedlings had greater stomatal conductance and were less water stressed than seedlings experiencing drought for the first time indicating hardened seedlings had adjusted physiologically to drought. Survival after transplanting in the controlled drought environment in a glasshouse was enhanced by the hardening treatments. Non hardened seedlings that had had their upper leaves manually removed immediately prior to transplanting to reduce leaf area (top-clipped) had similar survival to hardened seedlings. Stomatal conductance and leaf water potential after transplanting were higher in hardened and top-clipped seedlings than unhardened control seedlings or vegetative cuttings. Survival in the field trial was over 95% for all treatments, possibly as rain fell within 4 days of planting and follow-up rain occurred in the subsequent weeks. Neither the hardened or top-clipped seedlings planted in the field trial had reduced growth, increased propensity to form double leaders or worse stem form than control seedlings when measured at age 3 years.     

Effects of drought on isolates of <Emphasis Type="Italic">Bradyrhizobium elkanii</Emphasis> cultured from <Emphasis Type="Italic">Albizia adianthifolia</Emphasis> seedlings of different provenances

Albizia adianthifolia (Schumach) W. F. Wright, a N-fixing legume tree, has a wide distribution in Africa, in Ghana occurring in high rainfall forests and in seasonally droughted forests, and is associated in the Ghanaian forest zone with dry, infertile sites. We hypothesised that A. adianthifolia hosted different rhizobial strains in different forest types, and that these different strains would show different growth responses to moisture stress and different motility and mortality in droughted soil. Three isolates, extracted from seedlings of A. adianthifolia growing in three forest types differing in seasonal drought, were identified as Bradyrhizobium elkanii and exposed to varying levels of osmotic stress. Growth responses varied between the three strains, one of which displayed clear signs of drought tolerance. A novel approach using soil leaching columns was used to test the effects of soil pore water (in terms of neck diameter) on both the survival and movement of wet and dry forest rhizobial isolates through soil columns. The responses of the isolates were significantly different, the pore neck diameter, marginally insignificant and the drought treatment insignificant. Thus the dry forest isolate survived better in all treatments, and showed less response to the treatments, than the isolate from the wet forest. The results offer preliminary evidence that Bradyrhizobium elkanii strains from A. adianthifolia in Ghana have evolved in response to local differences in seasonal water availability. These differences could assist the selection of A. adianthifolia provenances for agroforestry or land rehabilitation.     

Agrobacterium-mediated genetic transformation of Camptotheca acuminata

UGPase gene related with wood cellulose synthesis was transferred into C. acuminata using the method of Agrobacte- rium-mediated genetic transformation, and an efficient transformation system was developed for C. acuminata on the basis of evaluations of several factors affecting Agrobacterium-mediated DNA transfer rate. The highest transformation rate was achieved when pre-cultttred leaf explants were infected with an Agrobacterium culture corresponding to OD600 （0.5） for 10 min, and cultured on explant regeneration medium for three days. The results of Southern hybridization showed that genomic DNA of the kanamycin-resistant shoots to an UGPase gene probe substantiated the integration of the transgene. Transformation efficiency （6%） was achieved under the optimized transformation procedure, This system should facilitate the introduction of important useful genes into C, acuminata.     

The impact of shade on morphology,growth and biomass allocation in <Emphasis Type="Italic">Picea sitchensis</Emphasis>, <Emphasis Type="Italic">Larix</Emphasis> × <Emphasis Type="Italic">eurolepis</Emphasis> and <Emphasis Type="Italic">Thuja plicata</Emphasis>

To determine the effect of shade on morphology, growth and biomass allocation in Picea sitchensis, Larix × eurolepis and Thuja plicata, seedlings were grown in the open or under shadehouses providing 25%, 50% and 75% reductions of full-light for two growing seasons. For most of the characteristics assessed there was no significant interaction between species and shade indicating that the morphological responses to changing shade treatments were not species-dependent. After two growing seasons the mean height increment for the three species was significantly greater in 25% (76.1 cm) and 50% shade (74.9 cm) than in the open (69.5 cm). Root collar diameter increment, shoot, root and total biomass declined significantly with increasing shade while the opposite was true for the height:diameter ratio. In both western red cedar and hybrid larch the shoot:root ratio was significantly greater in the shade while in Sitka spruce this characteristic was not influenced by shade. While all species had significantly greater specific shoot areas in 75% shade than in 0% shade, this trend was particularly pronounced in hybrid larch. In hybrid larch and western red cedar, the normalised specific projected shoot area increased significantly with increasing shade. The opposite trend was observed for Sitka spruce. We conclude that in the main the species studied demonstrated similar shade acclimation responses despite their reported differences in shade tolerance.     

Influence of initial age and size on the field performance of <Emphasis Type=Italic>Larix olgensis</Emphasis> seedlings

Quality of seedlings is important for the success of plantations. The field performance of five stock types of Olga Bay larch (Larix olgensis Henry) seedlings three seasons after planting was evaluated. High survival rates were achieved for all five types of planting stock in the first-year growing season when weeds were controlled. In the second and third-year growing seasons, significant differences were observed in survival rates among different stocktypes. The 1 + 1 type of Olga Bay larch seedling demonstrated better survival than 1 + 0 type of seedlings. 1 + 1 seedlings with diameter larger than 5.0 mm as well as 1 + 0 seedlings with diameter larger than 4.5 mm were suitable for reforestation. The 1 + 1 stocktype with a root collar diameter between 6.0 and 7.5 mm was considered optimal for the establishment of fast-growing and high-yield plantations. The number of lateral roots > 1 cm in length was the best predictor of field performance, however, the number of first order lateral roots with diameter > 1 mm at the tap root junction (FOLR (D > 1 mm)) was more feasible and sufficiently reliable to predict the field performance of the deciduous conifers. The initial height and root collar diameter of seedlings showed a significant correlation with the field performance for both 1 + 1 and 1 + 0 seedlings in the first and second-year growing seasons and thus can be adopted as an indicator for predicting potential field performance of seedlings.     

Seasonal variation of microelement contents in leaves of <Emphasis Type=Italic>Cyclocarea paliurus</Emphasis> among the provenances

Cyclocarya paliurus as a multiple function plant can accumulate biologically important microelement elements.To reveal the variation of selected microelement concentrations in leaves of C.paliurus provenances during the growing season,12 C.paliurus provenances in the field trial were sampled five times at approximately 1-month intervals.The method of inductively coupled plasma optical emission spectrometer(ICP-OES) was employed to determinate average concentrations of Fe,Mn,Zn,Cu and Se in leaves of 12 C.paliurus provenances.The results show that on average,the concentrations of five microelement in the leaves follows an order of Fe > Mn > Zn > Cu > Se.Variance analysis shows that there are significant differences in Fe,Mn and Zn concentrations among the twelve provenances(p<0.05),while there is no significant difference between Cu and Se concentrations.A significant difference was also observed in the concentrations of five microelements at the different sampling times(p<0.001),but the mean concentrations for each microelement showed different temporal dynamic patterns.Meanwhile,a significant correlation between concentrations of Se and other measured microelements was detected in the leaves of C.paliurus,except for Mn.Obtained results not only demonstrated that leaves of C.paliurus exhibited higher levels of microelements(Fe,Mn,Cu,Zn and Se),but also provided a basis for breeding strategies of superior provenances with rich content of microelements,and choosing optimum harvesting time for food industry in future.     

Problems of using pines in <Emphasis Type="Italic">Tuber melanosporum</Emphasis> culture: soils and truffle harvest associated with <Emphasis Type="Italic">Pinus nigra</Emphasis> and <Emphasis Type="Italic">P. sylvestris</Emphasis>

In Mediterranean pine forests, truffles and mushrooms generate greater profits than any other woodland products. However, there are no studies on Tuber melanosporum Vittad. associated with pines. For this reason, we have carried out a study of this truffle in mountain woods with Pinus sylvestris L. and P. nigra Arnold subsp. salzmannii (Dunal) Franco, in central Spain. Two hundred and eight Tuber melanosporum burns were monitored for 7 years in five different habitats within the same geographical area. An ANOVA test confirmed significant differences in carpophore production. In higher producing habitats, pines were less abundant. We also confirmed that in 433 burns, T. melanosporum was always unequivocally associated with the root base of Quercus or Corylus trees. Similarly, 14 truffle collectors confirmed that they had never found a single burn with carpophore production associated exclusively with pines. Nevertheless, soil analyses indicated that the soil of these pine woods was very favourable to Tuber melanosporum. We therefore conclude that at present Pinus nigra salzmannii and P. sylvestris are of little interest to Tuber melanosporum culture, as they hinder carpophore production. However, this study has also confirmed that Pinus nigra salzmannii and P. sylvestris mycorrhize easily with Tuber melanosporum, both in the laboratory and in natural environments. On this basis, we propose that pines may act as transmitters of T. melanosporum, although they do not induce fruiting. As a result, the commercial cultivation of Pinus nigra salzmannii and P. sylvestris seedlings mycorrhized with Tuber melanosporum is not recommended in truffle culture at the present time.     

Photosynthesis responses to various soil moisture in leaves of Wisteria sinensis

A study was conducted to determine the fitting soil moisture for the normal growth of two-year-old W. sinensis （Sims） Sweets by using gas exchange technique. Remarkable threshold values of net photosynthetic rate （Pn）, transpiration rate （Tr） and water use efficiency （WUE） were observed in the W. sinensis leaves treated by various soil moisture and photosynthetic available radiation （PAR）. The fitting soil moisture for maintaining a high level of Pn and WUE was in range of 15.3%-26.5% of volumetric water content （VWC）, of which the optimal VWC was 23.3%. Under the condition of fitting soil moisture, the light saturation point of leaves occurred at above 800μmol.m^2.s^-1, whereas under the condition of water deficiency （VWC, 11.9% and 8.2%） or oversaturation （VWC, 26.5%）, the light saturation point was below 400μmol.m^-1.s^-1. Moreover, the light response curves suggested that a special point of PAR occurred with the increase in PAR. This special point was considered as the turning point that indicated the functional transition from stomatal limitation to non-stomatal limitation. The turning point was about 600, 1000, 1000 and 400 μmol.m^-2.s^-1, respectively, at VWC of 28.4%, 15.3%, 11.9% and 8.2%. In conclusion, W. sinensis had higher adaptive ability to water stress by regulating itself physiological function.     

忍冬和华南忍冬叶表皮扫描电镜观察及其生态适应性研究

利用扫描电镜观察了忍冬（Lonicera jàponica Thunb）和华南忍冬（Lonicera confus）叶表皮形态特征,观察指标包括：气孔器、表皮毛、表皮细胞等.结果表明：气孔仅分布在下表皮,气孔器呈无规则型散生;上表皮细胞的垂周壁呈沟槽状下陷;下表皮密被表皮毛（包括腺状毛和非腺毛）,同时还分布有瘤状的草酸钙簇晶.为进一步证明这种瘤状结构是否为草酸钙簇晶,作者发现利用Fluo-3/AM（钙离子荧光指示剂）处理的活体叶片在激光共聚焦显微镜下能够发出强烈的荧光.此外,通过电子探针对瘤状物进行分析,发现其元素组成为C、O、Ca.上述叶表皮构造特征,有利于减少植物体水分散失,还有助于植物适应富钙的石灰土,从而适应我国西南岩溶区特殊的干旱、富钙的环境.电镜观察结果表明,在忍冬叶上表皮中脉处有呈线状分布的腺状表皮毛,而华南忍冬叶上表皮则无表皮毛分布,这一微形态特征可以作为二者种间特异性差别,从而为二者的合理区分提供一定的依据.     

Evaluation of efficiency of <Emphasis Type="Italic">Trichogramma evanescens</Emphasis> reared on different factitious hosts to control <Emphasis Type="Italic">Helicoverpa armigera</Emphasis>

The release of mass propagated egg parasitoids could be one option to control the lepidopteran pests. The efficiency of the parasitoid Trichogramma evanescens (Westwood) reared on eggs of three different factitious hosts; Sitotroga cerealella, Ephestia kuehniella and Galleria mellonella was studied for controlling bollworm Helicoverpa armigera. Efficiency of Trichogramma was studied by measuring parasitism rates, emergence rates, longevity and sex ratio. Wasps reared from each source were tested on the source host and on the target host, H. armigera under laboratory conditions. Rates of parasitism on H. armigera eggs, emergence rates of parasitoids and their longevity were the highest for wasps reared on H. armigera. Wasps reared on S. cerealella gave comparable rates. However, wasps from E. kuehniella gave the lower rates and G. mellonella gave the lowest ones. Parasitized eggs of H. armigera and S. cerealella produced more parasitoid females than eggs of E. kuehniella and G. mellonella. Results are discussed for magnifying efficiency of the parasitoid in controlling H. armigera in the field.     

Dynamics of non-structural carbohydrate reserves in pruned <Emphasis Type="Italic">Erythrina poeppigiana</Emphasis> and <Emphasis Type="Italic">Gliricidia sepium</Emphasis> trees

In alley cropping systems, fast growing leguminous trees are pruned to reduce competition with crops for light and to provide organic inputs for crop nutrition. Tree regrowth depends on non-structural carbohydrate reserves in the remaining tree parts. In this study, the dynamics of starch and soluble carbohydrates in roots and stems of completely pruned (all shoots removed), partially pruned (one branch retained on the pruned stump) and unpruned Erythrina poeppigiana (Walp.) O.F. Cook and Gliricidia sepium (Jacq.) Kunth ex Walp. trees were studied under humid tropical conditions in Turrialba, Costa Rica. Measurements on starch and soluble carbohydrates in roots and stems were made at 0, 2, 6 and 12 weeks after pruning during both a “rainy” and a “dry” season. In general, the dynamics of non-structural carbohydrates in roots and stems of pruned E. poeppigiana and G. sepium trees were similar. Starch concentration was highest in unpruned trees and higher in roots than in stems of pruned trees. The effect of pruning intensity was first observed in stems, and starch reserves were more depleted in stems than in roots, an effect more evident during the “dry” season. The critical tree regrowth stage for starch mobilisation was that of vigorous sprout development at six or four weeks after pruning particularly in completely pruned trees. At this time, fine root biomass and length and nodule biomass in pruned trees decreased. Survival of fine roots and nodules was greater in partially pruned than in completely pruned trees. Starch accumulation in roots recommenced at 12 weeks after pruning in G. sepium, and later than 12 weeks after pruning in E. poeppigiana roots. This study showed that E. poeppigiana responded better to pruning regimes than G. sepium. Recovery of trees after pruning is better when trees are partially pruned than when completely pruned.     

Analysis and characterization of the <Emphasis Type="Italic">Salix suchowensis</Emphasis> chloroplast genome

By screening sequence reads from the Salix suchowensis chloroplast (cp) genome that were generated by next-generation sequencing platforms, we assembled a complete circular pseudomolecule for the cp genome. This pseudomolecule is 155,508 bp long and has a typical quadripartite structure that contains two single copy regions, a large single copy region (LSC, 84,385 bp), and a small single copy region (SSC, 16,209 bp) separated by inverted repeat regions (IRs, 27,457 bp). Gene annotation revealed that the S. suchowensis cp genome encoded 119 unique genes, including four ribosome RNA genes, 30 transfer RNA genes, 82 protein-coding genes, and three pseudogenes. Analysis of the repetitive sequences revealed 31 tandem repeats, 16 forward repeats, and five palindromic repeats. In addition, a total of 148 perfect microsatellites, which were characterized as A/T dominant in nucleotide composition, were detected. Significant shifting of the IR/SSC boundaries was revealed by comparing this cp genome with those of other rosid plants. We also constructed phylogenetic trees to demonstrate the phylogenetic position of S. suchowensis in Rosidae based on 66 orthologous protein-coding genes present in the cp genomes of 32 species. Sequencing 30 amplicons based on the pseudomolecule for experimental verification revealed 99.88% accuracy for the S. suchowensis cp genome assembly. Therefore, we assembled a high-quality pseudomolecule of the S. suchowensis cp genome, which is a useful resource for facilitating development of this shrub willow into a more productive bioenergy crop.     

High-level expression of 4-coumarate:coenzyme A ligase gene Pt4CL1 of Populus tomentosa in E. coli

In order to investigate the enzymatic properties of the 4CL1 of Populus tomentosa, the recombinant expression vector pQE31-4CL1 was constructed. The recombinant was identified by three restriction endonucleases, then the vector pQE31-4CL1 was transformed into expression host M15 (pREP4) and induced by isopropyl-α-D-thiogalactoside (IPTG) to express 60 kD fused protein Pt4CL1. The biologically active Pt4CL1, expressed as soluble protein, was achieved with 0.6 mmol·L-1 IPTG induction as the ex-pression temperature declined from 37 to 28°C. The 6×His tag facilitates affinity binding to Ni2 -nitrolotriacetic acid (NTA) and enables one-step purification to acquire the molecular SDS-PAGE electrophoresis purity of the active 4CL1 protein by agarose cou-pled with Ni2 -NTA affinity chromatography. The optimal substrate for Pt4CL1 was 4-coumarate.     

Electroantennogram responses of <Emphasis Type="Italic">Adosomus</Emphasis> sp. to volatile components from <Emphasis Type="Italic">Artemisia ordosica</Emphasis>

Adosomus sp.eats the leaves and oviposits on the stems of Artemisia ordosica Krasch.Based on an analytical PTI-GC/MS method, 21 volatile organic compounds (VOCs) from the leaves of A.ordosica were identified.The major operating equipment con-sisted of a DB-5 column (30 m×0.32 mm×0.25 μm) and a flame ionization detector (FID).The amounts of the components from VOCs were determined by a peak area normalization method and 17 VOC components were identified by PTI-GC/MS.The elec-troantennogram (EAG) responses of...     

Effects of deer browsing on the survival and growth of <Emphasis Type="Italic">Abies homolepis</Emphasis> and <Emphasis Type="Italic">Picea jezoensis</Emphasis> var. <Emphasis Type="Italic">hondoensis</Emphasis> seedlings after fencing on Mt. Ohdaigahara

We evaluated the survival and growth of Abies homolepis and Picea jezoensis var. hondoensis seedlings on Mt. Ohdaigahara, where the population of sika deer (Cervus nippon) is high and an experimental fence has been in place for 13 years. No significant differences were detected in the survival of small seedlings between fenced and unfenced plots. The growth of A. homolepis was significantly higher in the fenced plot, but growth of P. jezoensis var. hondoensis did not show significant differences between fenced and unfenced plots. Seedlings of height ≤5 cm in the forest floor vegetation of the unfenced plot were probably too small for deer to find and browse, so they survived.