Fleshy fruits eating birds and their role in the seed dispersal of plants in Maoer Mountain, NE China

There are 16 species of fleshy-fruit cating birds in Autumn in Maoer Mt. NE China. According to their feeding strategies. we can divide them into 3 groups: 1. Pulp-cating birds, they get nutrition from pulp. so. their seeds are defecated completely. These birds have a great effect on seed dispersal. 2. Seed-cating birds, they obtain nutrition from the seed but pulp. Seeds are digested totally. They don’t disperse seeds at all. 3. Whole-fruit-eating birds, both seed and pulp are digested when passing through gut. They don’t have any effect on seed dispersal either. Supported by NSFC 39370137 (Responsible Editor: Sun Yueqi)     

Inhibition by pulp juice and enhancement by ingestion on germination of bird-dispersedPrunus seeds

To evaluate what prevents seed germination and why ingestion by birds enhances germination, we carried out germination experiments using bird-dispersed seeds of twoPrunus species (Prunus sargentii andP. ssiori) in the laboratory. Germination of seeds with following four treatments was compared: “Ingested seeds” excreted after feeding of fruits to birds; “Extracted seeds” deliberately extracted from the fruit pulp; “Juiced seeds” which were supplemented with the juice of the pulp after seeds had been deliberately extracted from the pulp; and “Intact seeds” in untreated whole fruits. Many ingested (27%, 23% inP. sargentii, 18% inP. ssiori) and extracted seeds (24% inP. sargentii, 17% inP. ssiori) germinated, and difference in germination percentages between ingested and extracted seeds were not significant, for eitherPrunus species. The Juiced seeds rarely germinated (2% inP. sargentii, 6% inP. ssiori), and seeds within intact fruits did not germinate. These results suggest that the fruit pulp and the juice of the pulp inhibit germination and the seeds could germinate without ingestion by birds once they had been manually extracted from pulp. Therefore, it is considered that bird ingestion enahnces germination by removing pulp, especially juice of the pulp, in these twoPrunus species.     

Negative effect of removing pulp from unripe fleshy fruits: seed germination pattern of Celtis sinensis in relation to the temporal context of fruit consumption

We explored the temporal effects of fruit consumption on the subsequent seed germination pattern of a fleshy-fruited tree, the Chinese hackberry (Celtis sinensis). Via nursery-based sowing experiments, we investigated (1) how pulp removal affected seed germination patterns at the different stages of fruit maturation, and (2) how the timing of seed dispersal (August, October, and December) affected the germination patterns of seeds from ripe fruits after the removal of pulp. We found that the removal of pulp from around the seeds of ripe fruit had no effect on the percentage and timing of germination. In contrast, the removal of pulp from seeds of unripe fruits largely reduced the germination percentage. The time of sowing did not affect the germination percentage, whereas the timing of germination was delayed for seeds that were sown later or under shaded environments.     

Timing of shedding seeds and cones, and production in different stands of Scots pines at Abernethy Forest, Scotland

A study was carried out over 11 seed years on the timing ofshedding of seeds and cones, and annual seed fall and cone productionin three stands of native Scots pinewood and a Scots pine plantationin Abernethy Forest, Scotland. Peaks in seed fall took placemainly in May, and cones were shed mainly between June and August.There were few residual seeds remaining in shed cones. Synchronizedpeaks in seed fall and cone production (mast years) took placeat 3-year intervals across the different stands. The differencebetween cohorts of high and low cone production ranged fromfactors of 5 to 20 among sites. Coefficients of variation forcone production ranged from 62 to 84 per cent among sites. Therewere no significant differences in cone production among sites,but there were site-related differences in seed fall. The largercanopy cover in the plantation probably accounted for the higherseed fall per square metre there, though variations in the amountof seed eaten by birds and mammals may also have been important.Canopy cover needs to be considered when converting cone densitiesunder crowns to cone density per unit of woodland area. A similarcalculation is difficult for seeds because they are lighterthan cones and many fall outside the area under the crowns.The results are discussed in relation to the potential for treeregeneration and the availability of food for birds and mammalsprior to seed dispersal.     

黄土干旱阳坡植被恢复种子处理技术研究

针对黄土干旱阳坡植被恢复中的缺水问题,以刺槐种子、侧柏种子为例进行了室内水瓶辅助法播种试验和田间保水囊法播种试验,研究了改善种子水分环境的技术手段。结果表明：利用以纸浆为主要成分制作而成的保水囊进行播种,能有效地提高刺槐种子的出苗率,但对侧柏种子没有明显效果。     

林木种子休眠研究评述

种子休眠,是指在充分满足各种发芽条件时,有生命力的种子一时不能发芽或发芽困难的自然现象。处于休眠的种子,种皮坚硬、含水量低,细胞内养分处于难溶态,代谢活动较低。一般将种子休眠划分为三个类型:即强迫休眠、生理休眠和综合休眠。种子生理休眠的机理包括:种果皮的抑制;植物激素的作用;种子的二次休眠;综合因素造成的休眠;分子变化等方面。     

Tree Recruitment from On-site Versus Off-site Propagule Sources During Tropical Forest Succession

The management of successional forests has become an increasingly important tool for tropical forest restoration on disturbed lands. Successful management depends on understanding factors governing tree recruitment during succession. Recruits can be on-site propagules surviving disturbance (e.g. saplings) or seeds arriving after disturbance. Among disturbed sites, the importance of seed arrival from off-site should increase as availability of on-site propagules declines. This study examines how seed arrival from off-site seemed to influence natural forest regrowth on logged plantations in Uganda. Specifically, the effect of seed arrival from mammals (determined directly) and birds (determined inferentially) was estimated in two plantations with high and three plantations with low quantities of saplings surviving logging. In both plantation types, first-year recruitment seemed to originate from on-site (seed bank and sprouts from damaged trees) and off-site sources (seed-dispersing birds). Recruitment declined 2–3 years after logging in all plantations despite high densities of seed-dispersing birds. Recruitment was generally greater in plantations with low initial quantities of on-site propagules, and by 4–6 years forest structure was similar between plantation types. Recruitment was dominated by bird-dispersed species, rather than mammal- or wind-dispersed species. Taken together, these results illustrate that disturbed areas with low initial on-site propagule availability have much potential for forest regrowth.     

Phenotypic variation of baobab (<Emphasis Type="Italic">Adansonia digitata</Emphasis> L.) fruit traits in Mali

We analyzed the phenotypic variation of baobab (Adansonia digitata L.) fruits from Mali to define the domestication potential of this species. 269 trees, selected from 10 provenances distributed along a rainfall gradient, were characterized. Five fruits were sampled from each tree. Total individual fruit weight was partitioned into shell, pulp, and seed weight. Ratios were calculated between pulp + seed and total weight, and between pulp and seed weight. For all the measured fruit traits, we detected significant differences between provenances, as well as between trees from the same provenance. Assuming that the measured traits are under genetic control, the latter facts indicate that there are considerable opportunities for tree selection on a local scale. However, candidate plus trees with specific properties, e.g., extremely high pulp or seed weight, were found only in some locations. Mean pulp yield per fruit might be considerably increased by selecting the 5% trees with the highest pulp weight (mean: 45 ± 1 g, best 5%: >100 g). The same might be true for seed production (mean: 71 ± 2 g, best 5%: >150 g). Also the ratio between pulp and seed weight can be an important fruit characteristic for selection: in fruits with a low ratio, relatively more pulp sticks to the seeds when separating the two fruit parts by grinding, and thus more pulp will be lost for further processing. We identified several trees with a high pulp weight combined with a high ratio between pulp and seed weight. It is concluded that there is considerable phenotypic variability in traits of baobab fruit in Mali, offering opportunities for cultivar selection.     

小叶杨种子贮藏试验研究

杨树种子粒小、种皮薄、含水量高,在一般条件下贮藏两个月即丧失发芽能力,生产上均采用随采随播的方法。由于杨树结实有周期性,为了增加苗木当年生长量,提高苗木质量需进行春播,于是,杨树种子贮藏技术的研究不仅在生产上有着重要意义,而且对延长小粒种子寿命的探索亦具有一定价值。我们从1980年开始对杨树种子进行了不同采种期、不同贮藏方法等多项试验研究,其目的在于确定小叶杨种子的最佳采种期、最优贮藏条件,探索采种期及贮藏方法的不同对种子品质的影响,并欲从中了解它们的相关性。     

HOARDING BEHAVIOR OF EURASIAN NUTCRACKER ANDITS ROLE IN THE DISPERSAL OF KOREAN PINE

INTRODUCTIONKoreanpine(Pinuskoraiensis)com-'monlyoccursinmixtUrewithsomehardwoodsPeCiesand,natUrally,becomesold-growth"forestcalledmixedbroad-leaved/Koreanpineforest.ThenatUralforestsmainlydistributedinnortheastChina.TheconesofKoreanpinearelarge,measuringupto2ocminsize.The....,iscalescannotopenuptoletthebig,winglessseedsoutwhentheconesbecomingdry.UndernatUralcondition,theseedsdon'tgerminateuntil2winterslater,buttheseedsinconesusuallybecomerottenowingtofungusorareforagedbysmallrodentsa…     

五味子种籽性状与种仁含油特性的个体变异规律

采用典型样株和随机取样的方法,对五味子种耔性状进行系统研究．结果表明:无性系间的种籽横径、种籽纵径、种籽厚度、种籽千粒重、种仁千粒重、种仁含油率等性状的差异达极显著水平;在供试的20个无性系中,9911、9907、9913、9919、9918、9914等6个无性系种仁含油率较高,分别为70．17％、69．77％、68．99％、67．51％、65．97％、64．15％;五味子种油的形成、积累与无性系的种籽千粒重、种仁千粒重、种籽横径、种籽纵径等指标关系不密切,而与种耔厚度关系密切,相关系数为0．670,相关关系达极显著水平．本研究结果可为以高含油率为目标的五味子品种选择提供依据．     

杉木遗传育种研究进展与对策

概述了我国杉木遗传育种研究的进展，针对存在的问题提出了对策，以期推动杉木良种化的进程。建议今后在杉木的遗传育种方面加强以下5个方面的研究：杉木制浆造纸纤维用材育种研究，杉木装饰用材育种研究，杉木营养遗传育种研究，杉木种子园技术及优良材料的区域试验，杉木优良种质基因资源选择收集和第3代育种研究。     

苗圃地鸟害生物防控技术研究

对吉林市江密峰苗圃的鸟类、种群数量及有害或有益状况进行调查,并采用驯化雀鹰进行生物防控鸟害技术研究,结果表明:该苗圃有鸟类24种,隶属3目11科,戴胜等10种鸟类主要捕食苗圃地害虫,属于益鸟。在真正啄食种子的14种鸟类中,危害程度存在明显差异,绝大部分危害较轻,严重危害种子的主要是燕雀和家鸽。使用雀鹰驱赶苗圃地中的鸟类,效果十分理想,不仅种子受损率降到经济允许指标以下,而且很少有鸟类受到伤害。     

Colonization of fleshy-fruited plants beneath perch plant species that bear fleshy fruit

We evaluated the contribution of seed dispersal by birds to the colonization of fleshy-fruited plants beneath plants that bear fleshy fruits and were used as perches by birds. Specifically, we investigated the composition of seeds and saplings sampled beneath nine fleshy-fruited perch plant species in a Pinus thunbergii stand on a coastal sand dune in central Japan. Both the numbers and the species numbers of bird-dispersed (pulpless) seeds differed significantly among the perch plant species. Nevertheless, the quantitative compositions of bird-dispersed seeds were similar among the perch plant species because of the significant positive interspecific correlations of species rank order in numbers of bird-dispersed seeds per species. Similar relationships were also found for saplings. For each perch plant species, the numbers of fallen conspecific seeds were significantly higher than or not different from those of heterospecific seeds. Furthermore, the numbers of pulpy seeds that fell directly from the perch plant were significantly higher than those of bird-dispersed conspecific seeds for seven of nine perch plant species. However, the densities of conspecific saplings were significantly lower than those of heterospecific saplings. Most pulpy seeds, therefore, probably do not germinate beneath their mother plants, and conspecific seeds probably accumulate in seed banks or are consumed by herbivores.     

Seasonal Trends in Abundance, Diet and Breeding of Common Crossbills (Loxia curvirostra) in an Area of Mixed Species Conifer Plantation Following the 1990 Crossbill 'Irruption'

Crossbills increased in abundance on lower Deeside, north-eastScotland, from July 1990 through the autumn, remaining numerousuntil the following June. Flock size initially increased, butdecreased towards late winter as breeding began. The timingof the population increase, and the sizes of the birds' billssuggested they were mainly immigrant Loxia curvirostra. Theirdiet changed seasonally in a pattern that could be explainedby the seed weight, cone toughness and seedfall phenology ofthe predominant conifers present. No breeding was recorded inautumn and winter when the birds were mainly feeding on Sitkaspruce, but commenced in early spring as they shifted to Scotspine. Breeding was late, and production poor, probably becauseonly some of the birds had large enough bills to feed efficientlyfrom the robust cones of Scots pine. It is argued that plantationforestry, by providing a novel range of conifer seeds, couldaffect selection for bill size in British crossbill populations.     

Effects of sea buckthorn (Hippophaë rhamnoides L.) seed and pulp oils on experimental models of gastric ulcer in rats

Oils from sea buckthorn (Hippopha? rhamnoides L.) seeds and berries have traditionally been used in the treatment of disorders of skin and mucosa in China. Compared with the negative control, oral administration of CO(2)-extracted seed and pulp oils, 7.0 ml x kg(-1) x day(-1) significantly reduced ulcer formation in water-immersion (P < 0.05) and reserpine-induced (P < 0.01) models in rats. In addition, administration of the two oils, 3.5 ml x kg(-1) x day(-1), significantly reduced the index of pylorus ligation-induced gastric ulcer (P < 0.05) and sped up the healing process of acetic acid-induced gastric ulcer (P < 0.01). The results suggested that the CO(2)-extracted sea buckthorn seed and pulp oils have both preventive and curative effects against experimental gastric ulcers in rats.     

Restoring dry Afromontane forest using bird and nurse plant effects: Direct sowing of Olea europaea ssp. cuspidata seeds

To identify the perspectives of seed sowing for reforestation of degraded dry Afromontane savanna in exclosures in northern Ethiopia, seeds of a fleshy-fruited, secondary climax tree, Olea europaea ssp. cuspidata, were placed under two pioneer shrub species (Euclea racemosa and Acacia etbaica) and in open microhabitats. Seed removal and germination rates were examined. The effects of bird ingestion, manual pulp removal and mechanical endocarp treatments on germination rates were also studied.

Pulp removal promoted seed germination, in particular in seeds without endocarp manipulation. Seed removal, presumably by rodents, was concentrated in narrow strips along linear soil conservation structures, and not different between shrubs and open microhabitats. In the absence of water stress, humus types did not have a significant effect on germination rates. Under field conditions however, germination was higher under Euclea canopies. The observed facilitative effect of Euclea shrubs on germination may be attributed to moisture retention effects, related to the deep humus layer and canopy architecture, preventing desiccation and promoting imbibition of seeds. When readily available Olea seeds are not used for seedling production, direct sowing of seeds in the humus under dense Euclea shrubs could offer a cheap complement to planting of nursery-raised seedlings for forest restoration projects in recovering Afromontane savanna.     

Seed dispersal networks in an urban novel ecosystem

The conflict resulting from the expansion of human activities into natural habitats affects the structure and functioning of ecosystems. Similarly, the anthropogenic redistribution of many species all over the world affects the composition of biological communities, possibly altering their capacity to sustain key ecological functions, such as seed dispersal. Urban parks are extreme examples of such novel ecosystems resulting from the anthropogenic redistribution of species in a new ecological framework. Here, we describe the avian seed dispersal network in an urban recreational woodland in central Portugal (c.79 ha). Four quantitative seed dispersal networks were assembled by identifying intact seeds in the droppings of mist-netted birds throughout the year. Overall, 1,244 seeds were identified, representing 33 links between 15 plant species and 11 bird species. Most birds dispersed alien seeds, but these represented a small proportion of the overall network (20 % of the seeds and 13 % of the droppings). Blackcap (Sylvia atricapilla) was the main disperser of native and alien seeds in all seasons, particularly those of the invasive Phytolacca americana. Fleshy fruits were more abundant in summer, but were more consumed in winter, presumably when other foods were difficult to find. Our study suggests that even in a highly managed urban park, seed dispersal networks can be temporally complex and variable and that a network approach can be an important monitoring tool to detect the status of crucial ecosystem functions in rapidly changing habitats such as urban parks.     

长白山北五味子原种与一新变种化学成分比较分析

以同一地块北五味子原种和变种为试验材料,进行成分检测与分析,结果表明:在7个指标中,变种和原种成分含量差异显著,其中:变种种子的主要有效成分乙醇乙脂的含量为49.60%,较原种(40.18%)高出9.42个百分点,乙素含量为23.48%,较原种(32.9%)低9.44个百分点,丙素含量为22.28%,略低于原种(23....     

沙米种子的萌发特性探讨

在实验室条件下研究了沙米种子的萌发特性,结果表明：沙米种子在全光照和半光照条件下表现出很高的发芽率和出苗率,而在黑暗条件下出苗率很低但发芽率仍然很高;沙米种子在埋深为0．5cm、1cm、2cm条件下表现出很高的发芽率和出苗率,而在埋深为3cm条件下发芽率和出苗率很低;沙米种子的发芽率和出苗率随降雨量的增加而增大,其中在降雨量为5mm条件下沙米种子几乎不能出苗。另外,即使在满足发芽的条件下,沙米种子也不会全部发芽,而是表现出明显的休眠性,以适应流沙特殊的环境条件。