河北省承德地区秸秆堆肥特性及腐熟度评价

以河北省承德地区的油葵秸秆、玉米秸秆、大豆秸秆与鸡粪为原料,设置4种不同配比（F1、F2、F3、F4）,于2009年秋末接种EM菌进行堆肥试验.通过对堆肥过程中堆体的温度、含水率、NH4＋-N、NO3--N、pH值、C/N、T值的测定,研究了不同配比对堆肥腐熟度的影响.采用大白菜种子发芽指数（GI）评价了堆肥的腐熟度和...     

Uptake and accumulation of potentially toxic metals (Zn, Cu and Pb) in soils and plants of Durgapur industrial belt

Uptake and accumulation of metals in crops may cause possible health risks through food chain. A field survey was conducted to investigate the accumulation of potentially toxic metals contamination in soil and plants irrigated with complexed industrial effluents. Concentration of Zn, Cu and Pb was 205-255,101-130,118-177 microg g(-1) in rhizosphere soils and 116-223, 57-102 and 63-95 microg g(-1) d. wt. in root and 95-186, 44-75 and 27-58 microg g(-1) d. wt. in shoot, respectively. The trend in Cu and Pb was in the order: soil > root > shoot > seed while in Zn it was soil > root > seed > shoot. Roots accumulated a larger fraction of soil Cu (70%) > Zn (67%) > Pb (54%). Bioaccumulation coefficient of soil to root ranged from 51-98 for Zn, 54-85 for Cu and 43-63 for Pb.Analysis of variance showed marginal change in bioaccumulation coefficient, noticed between plants (p > 0.05) while it varied significantly (p < 0.01) between tissues and metals. It increased from root to seed/fruit (root > shoot > seed/fruit) while decreased between metals from Zn to Pb (Zn > Cu > Pb). Out of the three, two Cu and Pb accumulated to phyotoxic levels while Zn was within threshold limit of phytotoxicity.     

Life cycle of Lampito mauritii (Kinberg) in comparison with Eudrilus eugeniae (Kinberg) cultured on different substrates

Growth (length, biomass and mean growth rate) and reproduction (total duration, clitellum appearance, clitellum completion, cocoon commencement, rate of cocoon production, incubation period, hatching success and mean number of hatching per cocoon) of indigenous Lampito mauritii (Kinberg) in comparison with exotic Eudrilus eugeniae (Kinberg) cultured on three feed substrates-clay loam soil, cowdung and pressmud (filter cake) have been studied over a period of 360 days under laboratory conditions (30 +/- 2 degrees C, 60-65% moisture). There is a positive relationship between length and biomass of both worms cultured on three feed substrates throughout the period of study The decrease of worm length and biomass observed slightly on 63-70th days in Lampito mauritii and 42-49th days in Eudrilus eugeniae cultured on three fed substrates are the results of the onset of cocoon production. After 270 days both worms in all these fed substrates show decreasing trends of length and biomass which are due to continued reproduction and aging. Among the three fed substrates, pressmud supports significantly maximum worm length and biomass (between 90-130 days in Eudrilus eugeniae and 110-170 days in Lampito mauritii), earlier attainment of sexual maturity (between 51-76 days in Limpito mauritii and 27-37 days in Eudrilus eugeniae), earlier commencement of cocoon production (37.7 +/- 0.0 days in Eudrilus eugeniae and 76.4 +/- 0.10 days in Limpitomauritii), shorter incubation periods (16.3 +/- 0.28 days in Eudrilus eugeniae and 26.7 +/- 0.81 days in Limpito mauritii), more hatching success (98% in Limpito mauritii and 86% in Eudrilus eugeniae), more mean number of hatchling percocoon (3.2 + 0.03 in Limpito mauritii and 2.6 +/- 0.06 in Eudrilus eugeniae) and shorter duration of life cycle (108.8 +/- 0.07 days in Limpito mauritii and 60.2 +/- 0.09 days in Eudrilus eugeniae) than cowdung and clay loam soil.     

Assessment of deposition of MEMC (seed dressing fungicide) in exposed rice grain through study of seedling growth parameters

Rice seed grains exposed to 240 ppm of seed dressing fungicide, MEMC showed increase in deposition of mercury with increase in period of observation (0h to 48h) in 765+/-5 mg of intact endosperm. The gradual increase in mercury deposition in intact endosperm caused simultaneous decrease in mercury content of the seed coat. Exposure periods of 5 to 20 min with 240 ppm of MEMC showed 5.5 to 8.72 microg of mercury deposition in 765+/-5 mg of intact endosperm. Increase in period of exposure (3 to 20 min) to 240 ppm of MEMC and also increase in chronic treatment to lower concentrations (1.5 ppm to 24 ppm) to seed grains have shown similar results in seedling growth parameters. Lower period of exposure or exposure to lower concentrations, both showed a significant inhibition of root growth, however the shoot growth showed stimulation. But higher exposure period or exposure to higher concentrations brought inhibition of both root and shoot growth. The exposure period showing 50% of root growth inhibition of 72h old seedling was calculated to be 10 min So also the chronic treatment showing the 50% of root growth inhibition was calculated to be 9 ppm. Ten min exposure of rice grain to 240 ppm of MEMC showed deposition of 7.11 microg of mercury in 765+/-5 mg of intact endosperm at 48h of observation (optimal phase of germinating process). Regression analysis indicated that by the time of 72h the intact endosperm and developing seedling might have acquired with a minimum amount of 10.23 microg of mercury from the seed coat. Finally it can be said that 10.23 microg of MEMC might be bringing 50% root growth inhibition in 72h old seedlings and 16.71 microg of mercury causing 50% inhibition of both root and shoot growth of 120h old seedlings.     

Dangerous liaisons disperse the Mediterranean dwarf palm: fleshy-pulp defensive role against seed predators

We chose the interaction between the Mediterranean dwarf palm (Chamaerops humilis) and its major seed disperser, the Eurasian badger (Meles meles), to evaluate the hypothesis that endozoochory is characterized by a mixture of conflicting and overlapping interests, with the capacity of being positive or negative for plant fitness. For instance, because of the potential protective role against invertebrate seed predators of C. humilis pulp, we expected that badger-ingested diaspores (i.e., seeds without pulp) would show lower survival than control seeds with the pulp attached. Conversely, due to the possible germination inhibitory function of C. humilis fruit pulp, it was also likely that badger-ingested seeds germinate in higher proportion than control seeds. We evaluated our predictions by carrying out a field sowing and monitoring it over two years. We estimated several stage-specific transition probabilities as well as the cumulative probability of seedling recruitment under different treatments. Our experimental results revealed the multifunctionality of C. humilis fruit pulp and that fruit ingestion by badgers had conflicting outcomes for the palm. As predicted, seed survival was much lower and seed predation by invertebrates much higher for badger-ingested than for control seeds, suggesting a defensive role of C. humilis ripe fruit pulp. All early-emerged seedlings came from badger-ingested seeds, suggesting an inhibitory function of fruit pulp. Though we did not find an effect of removal from the maternal environment on most components of fitness, seedling survival for badger-ingested seeds was higher away from than beneath conspecifics. Badgers imposed a sizeable short-term fitness cost to C. humilis and therefore could be categorized as a "dangerous liaison." Nonetheless, because of the high mobility of the badger, its dispersal service appears paramount given the severe fragmentation and isolation of most C. humilis populations across the highly humanized Mediterranean basin. Our study thus illustrates the necessity of assessing concurrently direct and indirect effects of plant-disperser interactions at different stages of the plant life cycle and recruitment process.     

Effects of restoration and reflooding on soil denitrification in a leveed Midwestern floodplain.

River floodplains have the potential to remove nitrate from water through denitrification, the anaerobic microbial conversion of nitrate to nitrogen gas. An important factor in this process is the interaction of river water with floodplain soil; however, many rivers have been disconnected from their historic floodplains by levees. To test the effect of reflooding a degraded floodplain on nitrate removal, we studied changes in soil denitrification rates on the Baraboo River floodplain in Wisconsin, USA, as it underwent restoration. Prior to this study, the site had been leveed, drained, and farmed for more than 50 years. In late fall 2002, the field drainage system was removed, and a gate structure was installed to allow controlled flooding of this site with river water. Soil moisture was extremely variable among zones and months and reflected local weather. Soil organic matter was stable over the study period with differences occurring along the elevation gradient. High soil nitrate concentrations occurred in dry, relatively organic-poor soil samples and, conversely, all samples with high moisture soils characterized by low nitrate. We measured denitrification in static cores and potential denitrification in bulk samples amended with carbon and nitrogen, one year before and two years following the manipulation. Denitrification rates showed high temporal and spatial variability. Static core rates of individual sites ranged widely (from 0.00 to 16.7 microg N2O-N x [kg soil](-1) x h(-1), mean +/- SD = 1.10 +/- 3.02), and denitrification enzyme activity (DEA) rates were similar with a slightly higher mean (from 0.00 to 15.0 microg N2O-N x [kg soil](-1) x h(-1), 1.41 +/- 1.98). Denitrification was not well-correlated with soil nitrate, organic matter content, or moisture levels, the three parameters typically thought to control denitrification. Static core denitrification rates were not significantly different across years, and DEA rates decreased slightly the second year after restoration. These results demonstrate that restored agricultural soil has the potential for denitrification, but that floodplain restoration did not immediately improve this potential. Future floodplain restorations should be designed to test alternative methods of increasing denitrification.     

Influence of acorn size and storage duration on moisture content, germination and survival of Quercus petraea (Mattuschka)

This study was conducted to evaluate how acom size (small, medium and large) and acorn storage duration (0, 5 and 17 months) influenced Quercus petraea (Mattuschka) moisture content and germination. Acorn size and storage duration did not significantly affect acorn moisture content, but they significantly affected acorn germination performance. When averaged for three acorn sizes, loss of germination performance occurred after 17 months of storage even when the moisture content did not reduce significantly and remain at the initial level (32.6%). Maximum germination percentage was observed in large and medium size classes before storage (93 and 95%, respectively) and after 5-month storage (94 and 93%, respectively), but after 17-month storage medium acorn size class exhibited the highest germination (68%). Small seed size class exhibited the lowest germination percentage and rate in each acorn storage duration. Acorn size also significantly affected seedling emergence and survival in the nursery and seedling emergence and survival was the lowest in small seed size class (85 and 80%, respectively). Although seedling survival of one-year seedlings in the nursery increased up to large seed size class, maximum survival in nursery conditions was observed in large and medium size classes (89 and 91%, respectively). Thus, acorn size grading in Q. petraea may result in higher germination performance within in a seedbed.     

Ecological and evolutionary mechanisms for low seed: ovule ratios: need for a pluralistic approach?

Central to the ecology and evolution of a broad range of plants is understanding why they routinely have submaximal reproduction manifested as low seed : ovule and fruit : flower ratios. We know much less about the processes responsible for low seed : ovule ratios than we do for fruit : flower ratios. Current hypotheses for low seed : ovule ratios are largely drawn from those for fruit : flower ratios, including proximate (ecological) causes of pollen limitation, resource limitation, and pollen quality, as well as the ultimate (evolutionary) hypothesis of "bet hedging" on stochastic pollination. Yet, such mechanisms operating on fruit : flower ratios at the whole-plant level may not best explain low seed : ovule ratios at the individual-flower level. We tested each of these proximate and ultimate causes for low seed : ovule ratios using the specialized pollination mutualism between senita cacti (Pachycereus schottii) and senita moths (Upiga virescens). Seed : ovule ratios were consistently low (approximately 0.61). Such excess ovule production by senita likely has a strong genetic component given the significant differences among plants in ovule number and the consistency in ovule production by plants within and among flowering seasons. Excess ovule production and low seed : ovule ratios could not be explained by pollen limitation, resource limitation, pollen quality, or bet hedging. Nevertheless, phenotypic selection analyses did show significant selection gradients for increased ovule number, suggesting that other evolutionary processes may be responsible for excess ovule production and low seed : ovule ratios. In contrast, low fruit : flower ratios at the whole-plant level were explained by an apparent equilibrium between pollen and resource limitation. Thus, mechanisms responsible for low fruit : flower ratios at the whole-plant level are not necessarily in accord with those of low seed : ovule ratios at the individual-flower level. This suggests that we may need to adopt a more pluralistic approach to seed : ovule ratios and consider alternative hypotheses, including a greater array of proximate and ultimate causes. Initial results of this study suggest that floral allometry, selection on correlated floral traits, stigma clogging with pollen grains, and style clogging with pollen tubes may provide promising avenues for understanding low seed : ovule ratios.     

Influence of pretreatment and desiccation on the germination of Laurus nobilis L. seeds

The effects of moist stratification, gibberellic acid (GA3) in combination with cold-moist stratification and desiccation on the germination of bay laurel (Laurus nobilis L.) seeds were studied. It was found that the external fleshy pericarp caused dormancy. There was also embryo dormancy and it was broken in seeds lacking pericarp either warm-moist stratification (20 degrees C day/4 degrees C night) or cold-moist stratification (4 degrees C) for 8 and 10 weeks, respectively. Gibberellic acid had little effect on germination percent and germination value of seeds without pericarp when used alone but significantly increased overall germination performance when used with cold-moist stratification. The viability of seeds dropped when the moisture content of the seeds was reduced by desiccation, and the time required to reach the critical moisture levels in the seeds differed in the different desiccation temperatures. The critical minimum seed moisture content for bay laurel was around 15% and the seeds showed the typical behavior of recalcitrant seeds.     

Field measurements of soil CO2 efflux in Heteropogon contortus dominated grassland of semi-arid eco-system

Seasonal changes in soil respiration (SR), soil temperature (ST) and soil moisture (SM) were compared between a barren land with no vegetation (control) and grassland dominated by Heteropogon contortus (L.) of a semi-arid eco-system during 2005-2006. A statistically significant (p<0.001) seasonal change in SR was observed between the two sites. The variation characteristics of soil CO2 effiux rates were observed during wet periods along precipitation gradients and it was consistently higher in grasslands than in control.A maximum soil CO2 efflux of 13.35 +/- 0.33 micromol m2 s-1 in grassland and 7.33 +/- 0.8 micromol m2 s- in control was observed during rainy season-ll, i.e., from October to December, a minimum of 1.27 +/- 0.2 micromol m-2 s-1 in grassland and 0.67 +/- 0.5 micromol m-2 s-1 in control during summer season, i.e., from March to June. A positive significant relation observed between soil respiration and soil moisture (r2above 0.8) and no significant relation was observed between soil CO2 efflux and soil temperature (r2 below 0.3). In water-limited semi-arid ecosystem, rewetting of the soil due to precipitation events triggered the increased pulses of soil respiration especially in grassland when compared to the barren land. The observed soil respiration rates during summer and after the subsequent precipitation events strongly indicated that the soil water-deficit conditions reduce the efflux both in barren land (control) and in grassland of semi-arid eco-system.     

Effect of temperature on growth and reproduction of the epigeic earthworm,Eudrilus Eugeniae (Kinberg)

Influence of temperature on growth and reproduction of Eudrilus eugeniae has been investigated by laboratory culturing at regulated 25.0 degrees C, 30.0 degrees C, 37.5 degrees C and 40.0 degrees C and in fluctuating (22.7-27.3 degrees C) room temperature of prevailing (winter) season over 16 weeks. All worms died during first and tenth week at 40.0 degrees C and 37.5 degrees C respectively. Weight (biomass) and growth of worms cultured at different temperature varied significantly (P<0.01). The mean growth (mg/g live weight/day) at 25.0 degrees C., 30.0 degrees C, 35.0 degrees C, 37.5 degrees C and in fluctuating temperatures was 1,074.04 +/- 6.07, 1,554.01 degrees 192.37, 148.1 +/- 15.28, 192.83 +/- 25.8 and 1450.4 +/- 162.1 respectively. Growth declined after maturity drastically with coccon production. At 25.0 degrees C though worms are sexually mature, they failed to produce cocoons within 16 weeks whereas, at 35.0 degrees C and 37.5 degrees C they did not sexually mature. Worms attained sexual maturity at a mean weight of about 1000 mg/worm. The mean per cent maturity was higher and earlier in fluctuating temperatures and at 30.0 degrees C than at 25.0 degrees C. Cocoon production was observed only at 30.0 degrees C and in fluctuating temperatures with a mean of 0.9 and 1.5 cocoons/ wom/week and the cumulative cocoon number of 10.8 and 14.7/worm over 16th week respectively. The fluctuating temperature of uncontrolled room environment and 30.0 degrees C were favorable for various life activities of the worms. Eudrilus eugeniae appears to have range of temperature optima more than 25.0 degrees C and less than 28 degrees C. The climatic conditions prevailing in whole of the peninsular India during winter season are favourable for employing this worm in intensive field scale vermiculturing practices.     

Effects of Forest Fragmentation on Seed Dispersal and Seedling Establishment in Ornithochorous Trees

Abstract: Habitat fragmentation increases seed dispersal limitation across the landscape and may also affect subsequent demographic stages such as seedling establishment. Thus, the development of adequate plans for forest restoration requires an understanding of mechanisms by which fragmentation hampers seed delivery to deforested areas and knowledge of how fragmentation affects the relationship between seed‐deposition patterns and seedling establishment. We evaluated the dispersal and recruitment of two bird‐dispersed, fleshy‐fruited tree species (Crataegus monogyna and Ilex aquifolium) in fragmented secondary forests of northern Spain. Forest fragmentation reduced the probability of seed deposition for both trees because of decreased availability of woody perches and fruit‐rich neighborhoods for seed dispersers, rather than because of reductions in tree cover by itself. The effects of fragmentation went beyond effects on the dispersal stage in Crataegus because seedling establishment was proportional to the quantities of bird‐dispersed seeds arriving at microsites. In contrast, postdispersal mortality in Ilex was so high that it obscured the seed‐to‐seedling transition. These results suggest that the effects of fragmentation are not necessarily consistent across stages of recruitment across species. Habitat management seeking to overcome barriers to forest recovery must include the preservation, and even the planting, of fleshy‐fruited trees in the unforested matrix as a measure to encourage frugivorous birds to enter into open and degraded areas. An integrative management strategy should also explicitly consider seed‐survival expectancies at microhabitats to preserve plant‐population dynamics and community structure in fragmented landscapes.     

Evaluating the success of functional restoration after reintroduction of a lost avian pollinator

Conservation translocation is a common method for species recovery, for which one increasingly frequent objective is restoring lost ecological functions to promote ecosystem recovery. However, few conservation translocation programs explicitly state or monitor function as an objective, limiting the ability to test assumptions, learn from past efforts, and improve management. We evaluated whether translocations of hihi (Notiomystis cincta), a threatened New Zealand passerine, achieved their implicit objective of restoring lost pollination function. Through a pollinator-exclusion experiment, we quantified, with log response ratios (lnR), the effects of birds on fruit set and seed quality in hangehange (Geniostoma ligustrifolium), a native flowering shrub. We isolated the contributions of hihi by making comparisons across sites with and without hihi. Birds improved fruit set more at sites without hihi (lnR = 1.27) than sites with hihi (lnR = 0.50), suggesting other avian pollinators compensated for and even exceeded hihi contributions to fruit set. Although birds improved seed germination only at hihi sites (lnR = 0.22–0.41), plants at sites without hihi had germination rates similar to hihi sites because they produced 26% more filled seeds, regardless of pollination condition. Therefore, although our results showed hihi improved seed quality, they also highlighted the complexity of ecological functions. When an important species is lost, ecosystems may be able to achieve similar function through different means. Our results underscore the importance of stating and monitoring the ecological benefits of conservation translocations when functional restoration is a motivation to ensure these programs are achieving their objectives.     

Birds as Suppliers of Seed Dispersal in Temperate Ecosystems: Conservation Guidelines from Real‐World Landscapes

Abstract: Seed dispersal by animals is considered a pivotal ecosystem function that drives plant‐community dynamics in natural habitats and vegetation recovery in human‐altered landscapes. Nevertheless, there is a lack of suitable ecological knowledge to develop basic conservation and management guidelines for this ecosystem service. Essential questions, such as how well the abundance of frugivorous animals predicts seeding function in different ecosystems and how anthropogenic landscape heterogeneity conditions the role of dispersers, remain poorly answered. In three temperate ecosystems, we studied seed dispersal by frugivorous birds in landscape mosaics shaped by human disturbance. By applying a standardized design across systems, we related the frequency of occurrence of bird‐dispersed seeds throughout the landscape to the abundance of birds, the habitat features, and the abundance of fleshy fruits. Abundance of frugivorous birds in itself predicted the occurrence of dispersed seeds throughout the landscape in all ecosystems studied. Even those landscape patches impoverished due to anthropogenic disturbance received some dispersed seeds when visited intensively by birds. Nonetheless, human‐caused landscape degradation largely affected seed‐deposition patterns by decreasing cover of woody vegetation or availability of fruit resources that attracted birds and promoted seed dispersal. The relative role of woody cover and fruit availability in seed dispersal by birds differed among ecosystems. Our results suggest that to manage seed dispersal for temperate ecosystem preservation or restoration one should consider abundance of frugivorous birds as a surrogate of landscape‐scale seed dispersal and an indicator of patch quality for the dispersal function; woody cover and fruit resource availability as key landscape features that drive seedfall patterns; and birds as mobile links that connect landscape patches of different degrees of degradation and habitat quality via seed deposition.     

Effects of tidally mediated litter moisture content on decomposition of Spartina alterniflora and S. patens

Relationships between flooding frequency, flooding duration, litter moisture levels, and litter decay rates were investigated across the natural hydrologic gradient common to intertidal salt marshes. The effects on litter decay of natural and experimental alterations of litter moisture content were assessed in both field litterbag experiments (conducted in a southern New Jersey salt marsh from 1989 to 1990) and laboratory incubations (1990). Overall, tidally mediated litter moisture content was the dominant factor controlling litter decay throughout the vegetated marsh. Rates of carbon loss were most closely related to litter moisture levels (r=0.84), which were directly related to flooding frequency (r=0.66) and duration (r=0.63). Litter moisture levels were related to elevation within the tidal range due to increasing surface levation from creekbank to high marsh (ca. 54 cm) and height of litter above the sediment surface. Carbon losses from litter of short and tall form Spartina alterniflora Loisel. and S. patens (Aiton) Muhl. along the marsh elevation gradient indicate that while some of the variations in decay rates may be due to litter type, litter moisture accounted for most of the observed variation between marsh zones and within each litter type. Mousture levels are also affected by the water retention capacity of each litter type, which may also secondarily influence decay rates. Short-term incubations of litter indicated that CO₂ evolution was positively related to moisture content with negligible respiration at moisture levels below 15% (fresh mass), increasing to a maximum between 65 and 75% depending upon litter type. Since most Spartina spp. litter remains above the marsh surface where it maintains a lower moisture content than surface litter, the use of surface litterbags may overestimate rates of carbon loss in some systems. In addition, since changes in elevation of only a few centimeters had significant effects on both litter moisture levels and decay rates, slight changes in tidal regime may have important consequences for organic matter cycling in salt marshes by affecting litter decomposition processes.     

Flying foxes cease to function as seed dispersers long before they become rare

Rare species play limited ecological roles, but particular behavioral traits may predispose species to become functionally extinct before becoming rare. Flying foxes (Pteropodid fruit bats) are important dispersers of large seeds, but their effectiveness is hypothesized to depend on high population density that induces aggressive interactions. In a Pacific archipelago, we quantified the proportion of seeds that flying foxes dispersed beyond the fruiting canopy, across a range of sites that differed in flying fox abundance. We found the relationship between ecological function (seed dispersal) and flying fox abundance was nonlinear and consistent with the hypothesis. For most trees in sites below a threshold abundance of flying foxes, flying foxes dispersed < 1% of the seeds they handled. Above the threshold, dispersal away from trees increased to 58% as animal abundance approximately doubled. Hence, flying foxes may cease to be effective seed dispersers long before becoming rare. As many species' populations decline worldwide, identifying those with threshold relationships is an important precursor to preservation of ecologically effective densities.     

晋西黄土区林草复合界面雨后土壤水分空间变异规律研究

利用统计学方法对晋西黄土区林草复合系统界面上雨后表层（0～10 cm）、亚表层（10～20 cm）和20～40 cm土层土壤水分空间变异性进行研究。结果表明：草地、林地以及二者组成的林草界面的土壤水分含量、变异系数差别均不大,土壤水分含量随着深度的增加而减少,但土壤水分变异系数则相反;移动窗口法分析表明,林草界面对表层和亚表层的土壤水分影响范围均为4.0 m;草地土壤质量含水量的变异函数模型可以拟合成高斯模型,林地和林草界面则可以拟合球状模型,草地土壤水分总体空间异质性要大于林地和林草界面,草地土壤水分变异函数的平均变程为10.96 m,林草界面及林地土壤水分的平均变程分别为5.37 m和4.31 m。对于描述界面土壤水分分布情况,克立格制图直观性强,具有良好效果。     

处理污水后陶粒作为栽培基质的试验

以秸秆-粉煤灰陶粒（比表面积为7．925m2·g-1）作为曝气生物滤池（BAF）载体填料,处理城市污水和餐饮废水,其COD、NH3-N和TP去除率分别为90．33％、77．44％、82．41％和86．50％、68．98％、80．30％。对处理污水后陶粒的农用资源化可行性进行评估,考察陶粒不同施用量对小白菜（Brassicachinensis）种子萌发、生长状况和产量的影响。结果表明,处理污水后陶粒的性能指标达到GB8172—87《城镇垃圾农用标准》;陶粒质量分数为20％时小白菜种子发芽率最高,且萌发较快,在5d时达到100％;随陶粒施用量增加,小白菜长势更好,产量大致呈增加趋势,陶粒质量分数为80％时增产率最高,为352．51％。但陶粒施用量越高,栽培基质抗干旱能力越差,陶粒质量分数为20％和40％处理具有较好的土壤保湿效果。     

包膜材料对土壤酶活性的影响

以自然资源＂水冬瓜果油＂为包膜材料,利用盆栽试验,共设5个处理,研究在有菊花吸收养分的情况下,水冬瓜（Idesia polycarpa maxim.var.vestita dies）油包膜材料在土壤中的降解性能及对土壤酶活性的影响。结果表明：水冬瓜油包膜材料随土壤含水量的增加,降解速率加快。种植菊花的土壤过氧化氢酶、蔗糖酶、脲酶活性也呈现先上升、后下降的趋势。在土壤含水量为30%时,包膜材料半衰期只有62 d;在处理3（果油85%＋调理剂15%）中,土壤过氧化氢酶、土壤蔗糖酶和脲酶数量增加最多。因此,水冬瓜果油85%＋调理剂15%和土壤含水量30%,有利于土壤酶活性的提高,从而加快包膜材料的降解速度。     

Linking fruit traits to variation in predispersal vertebrate seed predation, insect seed predation, and pathogen attack

The importance of vertebrates, invertebrates, and pathogens for plant communities has long been recognized, but their absolute and relative importance in early recruitment of multiple coexisting tropical plant species has not been quantified. Further, little is known about the relationship of fruit traits to seed mortality due to natural enemies in tropical plants. To investigate the influences of vertebrates, invertebrates, and pathogens on reproduction of seven canopy plant species varying in fruit traits, we quantified reductions in fruit development and seed germination due to vertebrates, invertebrates, and fungal pathogens through experimental removal of these enemies using canopy exclosures, insecticide, and fungicide, respectively. We also measured morphological fruit traits hypothesized to mediate interactions of plants with natural enemies of seeds. Vertebrates, invertebrates, and fungi differentially affected predispersal seed mortality depending on the plant species. Fruit morphology explained some variation among species; species with larger fruit and less physical protection surrounding seeds exhibited greater negative effects of fungi on fruit development and germination and experienced reduced seed survival integrated over fruit development and germination in response to vertebrates. Within species, variation in seed size also contributed to variation in natural enemy effects on seed viability. Further, seedling growth was higher for seeds that developed in vertebrate exclosures for Anacardium excelsum and under the fungicide treatment for Castilla elastica, suggesting that predispersal effects of natural enemies may carry through to the seedling stage. This is the first experimental test of the relative effects of vertebrates, invertebrates, and pathogens on seed survival in the canopy. This study motivates further investigation to determine the generality of our results for plant communities. If there is strong variation in natural enemy attack among species related to differences in fruit morphology, then quantification of fruit traits will aid in predicting the outcomes of interactions between plants and their natural enemies. This is particularly important in tropical forests, where high species diversity makes it logistically impossible to study every plant life history stage of every species.