The relative importance of invertebrate and microbial decomposition in a rainforest restoration project

Tropical rainforests are increasingly disturbed by human activities. While restoration projects often succeed in replacing tree cover, they rarely manage to restore soil function. Consequently, there is an urgent need to understand the changes that occur during soil restoration. Model ecosystems such as the Eden Project present an ideal opportunity to investigate these changes. The Eden Project was built 15 years ago, and its plants grown from seedlings, or sown directly into a soil made up of standardized mixtures of recycled organic material. Today, the Eden Project's rainforest biome consists of a diverse community of plants, invertebrates, and microorganisms. Different areas within the biome are managed differently, allowing us to separate the relative contributions of decomposers under differing physical conditions. Litterbag experiments revealed significant differences in decomposition rates in bags of different mesh sizes. Phospholipid fatty acid analysis revealed that microbial biomass and community structure varied under different management regimes. Soil enzyme assays revealed that glucosidase activity increased in soils with more organic matter, whereas phenol oxidase activity increased in more alkaline soils. Our study takes a step toward understanding the interactions between invertebrates and microbes, and the way in which soils function during restoration.     

Accumulation and persistence of a nuclear polyhedrosis virus of the cabbage looper in the field

A nuclear polyhedrosis virus of the cabbage looper, Trichoplusia ni, was applied to foliage of Fall-planted broccoli and cabbage plants. Soil bioassays demonstrated that appreciable quantities of active virus accumulated in the upper 1 cm of the soil of plots sprayed with 10, 20, and 100 larval equivalents (LE)/acre as well as in unsprayed plots. After completion of the spray program, soil from plots treated with 8 foliar applications of 10 LE/acre contained only slightly more virus than the soil from unsprayed plots, but considerably more virus accumulated in plots treated with 20 and 100 LE/acre. The accumulation of virus continued after the completion of spraying and considerable quantities of active virus persisted through the winter.     

Interactions of crop density of field beans, abundance of Aphis fabae Scop., virus incidence and aphid control by chemicals

The number of Aphis fabae Scop. per plant and per acre developing on field beans (Vicia faba L.) was inversely related to seeding rate (i.e. plant density) except sometimes at very low rates; with equal numbers of plants per acre, fewer aphids developed on plants in rows 11 in. than 22 in. apart. Plots sown in mid-March with more than about 150,000 plants per acre were more attractive than less dense stands to colonizing alate A. fabae, but established colonies multiplied most on the sparsest and least on the densest plots. The number of plants per acre infected by pea leaf-roll virus was inversely related to planting density. There were more virus-infected plants on II in. than on 22 in. spaced rows-in contrast to the numbers of A. fabae. A single spray with demeton-methyl, timed to control A. fabae, did not significantly decrease virus incidence. Grain yields of sprayed plots were little altered by increasing the seed rate above a critical minimum, except in one year when the densest crops lodged. Increased yields from spraying were closely related to the numbers of A. fabae on unsprayed plots. Dense planting (more than 400,000 plants per acre) prevented or greatly decreased losses caused by A. fabae in unsprayed plots except in one year when the aphids were exceptionally abundant.     

Growth of water hyacinths in treated sewage effluent

Two thousand plants of the water hyacinth,Eichornia crassipes Solms., were introduced on April 11, 1971, into a series of five ponds, each 5000 sq. ft. in area and 2.6 ft. deep. Treated waste water effluent from the Ames sewage treatment plant filled the ponds and was added to pond 1 at 127 gallons per minute. By growth and vegetative reproduction, these plants increased to more than 500,000, and all five ponds were covered completely by July 26. On that date, the extrapolated estimate of total wet weight was 287 U.S. tons/ acre (645 metric tons/hectare; 64500g/m²). The estimate of oven dry weight was 13.2 U.S. tons/acre (29.7 metric tons/hectare; 2970g/m²). Ammonia and nitrate disappeared rapidly from the pond water, and phosphate concentrations were lowered appreciably. Evapotranspiration and seepage accounted for water losses of more than 0.5 inches per day. The potential economic values of this plant and its possible use in tertiary treatment to reduce N and P components in waste waters are discussed briefly.     

The potential for protein production from green plants

Data on protein yields show that forage crops, particularly alfalfa, produce several times more protein per acre than do seed crops. Amino acid analyses and estimations of biological values by enzymatic hydrolysis and feeding trials indicate that protein concentrates from green plants have high nutritive value. The protein concentrates from 10 plant species had a similar amino acid composition and biological value which indicates that good protein might be obtained from many plant species. It is suggested that the use of the fibrous residue as a feed for ruminants and the use of the protein concentrate as a high protein feed or base for processing into new protein foods may make it possible for the production of protein from green plants to compete with other sources of protein. This would markedly increase protein production per acre and allow the use of new plant species in our agriculture. The need for more research on protein production from different types of green plants and on ways to harvest, concentrate and process their proteins into edible forms is discussed.     

Quantitative analysis of CryIA(b) expression in Bt maize plants,tissues, and silage and stability of expression over successive generations

The range and stability of expression of the transgenic CryIA(b) protein was examined in Ciba Seeds Bt maize plants derived from Event 176. Specifically, CryIA(b) levels were determined for: (1) various plant tissues and developmental stages in three maize lines from 1993 field tests; (2) pollen and leaves from plants representing four backcross generations of two genotypes; (3) leaves of 6 precommercial hybrids; and (4) silage from one Bt maize hybrid. Significant levels were found only in pollen and leaves. Genetic background did not greatly impact the level seen in either tissue. CryIA(b) expression in maize plants derived from transformation Event 176 was stable over at least four successive generations. On a per acre basis, the highest amount of CryIA(b) protein (estimated to be 2-4 g CryIA(b) protein/acre) was found to occur at anthesis, consistent with the stage at which maximum plant vegetative biomass is reached. CryIA(b) was not detected in silage prepared from CryIA(b)-expression plants. The maize-expressed CryIA(b) protein was found to have the expected size and to be immunoreactive with antibodies prepared against crystals from Bacillus thuringiensis subsp. kurstaki.     

Plant Traditional Culture of Populus euphratica and Populus pruinosa of Uyghurs Folk ——A Case Study in Xinjiang Lopnur

The study on traditional knowledge and experience of using plants by Uyghurs folk people has a potential application in socio economic development and resource protection. Populus euphratica Oliv and Ppruinosa Schrenk are major plants in Taklimakan desert ecosystem of Xinjiang. This study aims to ascertain the Lopnur Uyghurs traditional knowledge on two Populus species and their cultural system related to these species. We investigated the key informants for interviews on using Populus plants. The Populus plants were used for various purposes. The white alkali crystals are using for the treatment of bloating, sore throat, stomach ulcers, duodenal ulcers and indigestion and also in soda, while black crystal is used for the treatment of back pain, leg pain, swelling and relieve pain. Alkali crystals are even used as shampoo after a simple processing and also as a laundry detergent. Populus plants water is applied as a treatment of neurasthenia. It is also used for anti aging, reducing blood pressure, high cholesterol and heart morbidity. Plants foliages are used as veterinary medicine such as bloating and rot of muscular and stomach of livestock. In addition, Lopnur people used the plants to build the Desert Ecological Park and controlling desertification. This article ascertained the two Populus speceis and Lopnur Uyghurs cultural system. Present study will improve the conservation of Lopnur Uyghurs folk indigenous/ traditional knowledge on Populus plants and to promote the sustainable development in the socio economic diversity.     

Comparative study of two largely infilled estuaries: The Eden Estuary (Scotland) and the Ria de Foz (Spain)

Two small estuaries, the Eden Estuary of eastern Scotland and the Ria de Foz of north west Spain, are compared. The former was glaciated during the Pleistocene, the latter was not. These water bodies are macrotidal, of similar size, entrance morphology and advanced state of sedimentary infill. There are, however, major differences in their sedimentary dynamics partly as a result of anthropogenic interference. A training wall partially confines the main channel of the Ria de Foz, whereas the Eden Estuary lacks comparable structures. Prior to the extension of the Foz wall, the rate of migration of a spit at the mouth of the ria was up to one order of magnitude greater than that of a similar spit in the Eden Estuary. Following completion of the wall, the rate of spit erosion in the Ria de Foz increased to two orders of magnitude greater than that of natural processes in the Eden. A beach nourishment scheme at Foz, relocating sediment deposited within the Ria, has succeeded in stabilising the spit and substantially reducing erosion. Relative stability of land and sea may have existed over the last 5,000 years at Foz but not at the mouth of the Eden, where isostatic uplift has exceeded sea level rise. The requisite stability for complete sedimentary infill at Foz may not exist owing to the predicted worldwide rise of sea level due to global warming. The rise of sea and land levels around the Eden Estuary are now believed to be counterbalanced, providing the necessary geological conditions for complete sedimentary infill.     

Nutrient content of the moist tropical forest of Ghana

Summary The total weight of vegetation on an area of just over 1 acre of old secondary forest in the moist forest zone of Ghana has been determined, and found to be equivalent to roughly 150 tons per acre dry weight. The nutrient content of each component of the vegetation was also determined and showed that the amounts of the major nutrients immobilised in the vegetation were: N, 1,800 lb./acre; P, 120 lb./acre; K, 800 1b./acre; Ca, 2,400 lb./acre; Mg, 350 lb./acre. The corresponding amounts of nutrients in the top foot of soil supporting the vegetation were: total N, 4,100 lb./acre; available P, 11 lb./acre; exchangeable K, 580 lb./acre; exchangeable Ca, 2,300 lb./acre; exchangeable Mg, 330 lb./acre. About half the nutrients stored in the vegetation were contained in readily combustible material, and except for N would be released to the soil if the forest were cleared and burnt for cultivation. The quantity of roots and the amounts of nutrients contained in them were not sufficiently great to make an important addítion to the nutrient supply in the soil during subsequent cultivation. Of the total quantity of roots supporting the vegetation 85.5 per cent by weight were within 1 foot of the soil surface.     

The control of Aphis fabae Scop, on spring-sown field beans (Vicia faba L.)

Disulfoton or phorate granules or demeton-S-methyl, menazon and vamidothion sprays, applied once in early June as preventive treatments before heavy aphid colonies developed, gave good control of Aphis fabae Scop, on field beans. Phosalone gave relatively poor results and DDT was ineffective. Applications in June to crops sown in February and early March were made with minimal wheel damage to the crop and are known to be less harmful to bees than sprays at flowering time. Eradicant treatments with demeton-S-methyl and dimethoate sprays or with disulfoton or phorate granules on heavily infested plants during flowering were also effective, but menazon was less satisfactory. These eradicant sprays are likely to be harmful to bees, and wheel damage in late June reduced yield by 1–2 cwt/acre (125–250 kg/ha). Peak populations of 3000 aphids/plant in early July reduced yield by 6 cwt/acre (750 kg/ha) in one trial.     

THE PHYTOTOXIC EFFECTS OF D.D.T., B.H.C., PARATHION AND TOXAPHENE ON TOBACCO

No phytotoxic effect was seen following a pre-sowing spray of tobacco seed-beds with 27 lb./acre technical D.D.T. or after an application of the same material at 75.6 lb./acre to 3-week-old tobacco seedlings.
A pre-sowing application of parathion (diethyl para nitrophenyl thiophosphate) (2 % dust) at 1–8 lb. parathion per acre had no harmful effect. Used on 3-week-old tobacco seedlings at the excessive rate of 22.7 lb./acre it caused serious stunting and many deaths.
Toxaphene (chlorinated camphene: empirical formula C₁₀H₁₀Cl₈), applied as a 25 % wettable powder in a pre-sowing spray at 6-4 lb. toxaphene per acre, did not injure tobacco seedlings.
No residual phytotoxic effects appeared in beds re-sown 4 months after being treated with parathion or toxaphene at the pre-sowing doses given above.
Benzene hexachloride, applied before sowing at doses above 1.6 lb. technical B.H.C. per acre, suppressed root development in newly germinated tobacco seedlings. B.H.C. dusts used on n-day-old seedlings at 2–25 lb. technical B.H.C. per acre caused temporary distortion and stunting. Up to 11 lb./acre these symptoms were transitory: at 37.5 lb./acre many plants were killed and the remainder severely stunted. Resistance to these phytotoxic effects increased with age of plant, but 3-week-old tobacco seedlings showed considerable mortality after the application of 75.6 lb./acre of technical B.H.C.
Beds re-sown 4 months after the application of 6-4 and 12.8 lb. respectively of technical B.H.C. per acre showed no phytotoxic effect, but, as tobacco seed is sown on the soil surface, the effect of the B.H.C. may have been merely masked, and it is not safe to assume that there was no residual effect. The actual persistence of B.H.C. in the soil was not determined.
The possible mechanism of action of the B.H.C. effect is discussed.     

THE RELATION BETWEEN INFESTATION BY THE STALK BORER, BUSSEOLA FUSCA, AND YIELD OF MAIZE IN EAST AFRICA

The relation between yield and infestation by the maize stalk borer, Busseola fusca Fuller, is expressed as a series of regression lines for crops of different potential yields. The reasons are given for assuming that the regression is rectilinear, and that the regression coefficient b , or rate of fall in yield, is proportional to the maximum expected yield of the crop, that is that b
For the crops examined, the formula for a general regression line of yield, as hundreds of pounds of dry grain per acre, on infestation, as the percentage of plants attacked transformed to angles, is y = 45.1–0.55 x for a high-yielding area, and y = 14.55–0.23 x for a lower yielding crop. This is equivalent to a 35 lb./acre increase in grain yield for every 1% decrease in infestation for the higher yielding group, and 17 lb. increase per 1% decrease for the lower.
The applications of the relationship are discussed, in particular to studies of the economics of control by insecticides, and of the accuracy of methods of sampling infestations.     

EFFECTS OF PREVIOUS WHEAT CROPS, SEED-RATE AND NITROGEN ON EYESPOT, TAKE-ALL, WEEDS AND YIELDS OF TWO VARIETIES OF WINTER WHEAT: FIELD EXPERIMENT 1954-56

In a replicated field experiment mean yields of wheat from plots that, in the preceding 2 years, had carried oats, beans or potatoes were 39.2 and 42.6 cwt. per acre in 1954 for Holdfast and Cappelle, respectively; 42.8 and 55.8 in 1955 and 34.9 and 49.6 in 1956. Previous wheat crops had more effect than any other treatment in increasing the incidence of eyespot, take-all and weeds and in decreasing the number of ears per unit area and the yield of grain. In 1956 on plots carrying the first, second and third successive wheat crops the percentages of straws with eyespot were respectively 12, 54 and 42 and with take-all 0.1, 1 and 16. Cappelle was less severely infected by eyespot than Holdfast. The second and third successive wheat crops yielded an average of 23.3 cwt./acre less than the first wheat crop. Cappelle consistently yielded more than Holdfast, the mean difference being 13.8 cwt./acre after potatoes but only 3.8 cwt./acre after two wheat crops. The higher seed-rate gave an average increase in grain yield of 3.3 cwt./acre; but where eyespot and take-all were both severe the lower seed-rate yielded as much total and more dressed grain than the higher. Wheat given a spring top dressing of 6 cwt./acre Nitro-Chalk yielded an average of 4 cwt./acre more grain than wheat given 3 cwt./acre.     

Plants as bioreactors for the production of vaccine antigens

Plants have been identified as promising expression systems for commercial production of vaccine antigens. In phase I clinical trials several plant-derived vaccine antigens have been found to be safe and induce sufficiently high immune response. Thus, transgenic plants, including edible plant parts are suggested as excellent alternatives for the production of vaccines and economic scale-up through cultivation. Improved understanding of plant molecular biology and consequent refinement in the genetic engineering techniques have led to designing approaches for high level expression of vaccine antigens in plants. During the last decade, several efficient plant-based expression systems have been examined and more than 100 recombinant proteins including plant-derived vaccine antigens have been expressed in different plant tissues. Estimates suggest that it may become possible to obtain antigen sufficient for vaccinating millions of individuals from one acre crop by expressing the antigen in seeds of an edible legume, like peanut or soybean. In the near future, a plethora of protein products, developed through ‘naturalized bioreactors’ may reach market. Efforts for further improvements in these technologies need to be directed mainly towards validation and applicability of plant-based standardized mucosal and edible vaccines, regulatory pharmacology, formulations and the development of commercially viable GLP protocols. This article reviews the current status of developments in the area of use of plants for the development of vaccine antigens.     

The effects on soil fauna of insecticides tested against wireworms (Agriotes spp.) in wheat

The organophosphorus insecticides Bayer 38156 (O-ethyl S-p-tolyl ethyl phosphonodithioate), trichloronate, Stauffer N 2790 (O-ethyl S-phenyl ethyl phosphonodithioate), thionazin and fenitrothion were compared with aldrin, dieldrin and γ-BHC for their effects on soil fauna, particularly wire-worms, and on crop yields in 1964 and 1965. At 1·5 lb active ingredient/acre, none of the organophosphates had as great an effect on wireworms as an aldrin spray at 2·25 lb a.i./acre or a dieldrin seed dressing at 2·25 lb a.i./acre. Some treatments significantly increased and some significantly decreased numbers of mites and Collembola. Except for Allolobophora chlorotica in plots treated with Bayer 38156, earthworm numbers were greater in plots sprayed with Bayer 38156 or aldrin, or sown with dieldrin-dressed seeds, than in untreated plots. In May 1964, one month after sowing, untreated plots had significantly fewer plants than plots sprayed with aldrin, trichloronate or Bayer 38156, or sown with γ-BHC or dieldrin-dressed seeds, but yields from untreated plots at harvest were high for such a large wireworm population and did not differ significantly from yields of treated plots in either year. The persistence of thionazin and Bayer 38156 in treated plots was measured by a bioassay using Collembola. Bayer 38156 was detected in plots 1 month after spraying but not after 6 months. Thionazin left detectable residues 1 month after spraying in the two acid plots but not in the two alkaline plots. More frequent samples taken from thionazin-treated plots in 1965 showed a similar pattern of persistence, and laboratory tests, using soil mixed with various amounts of powdered calcium carbonate, confirmed that thionazin persisted longer in more acid soils.     

陇中黄土高原农村经济结构变化对退耕还林(草)的响应

黄土高原退耕还林(草)政策的实施有效改善了区域生态环境,然而其对社会经济的影响存在明显的地域差异。以甘肃省定西市安定区近郊凤翔镇和远郊鲁家沟镇为例,采用重复测定方差分析、主响应曲线分析和相关分析等解析2镇1998—2015年农村经济结构及收入变化对退耕还林(草)政策实施的响应特征,确定退耕还林(草)政策实施驱动的土地利用变化与农村收入之间的关系。研究发现:(1)退耕还林(草)政策实施解释了2镇70.4%的农业收入结构差异,因政策的实施推动了小麦等夏粮作物向玉米、马铃薯等秋粮作物的转变,进而影响了农业收入结构的变化;(2)退耕还林(草)政策对农村经济结构的影响弱于对农业收入结构的影响,它解释了2镇54.1%的农村经济结构差异,近郊凤翔镇农村经济收入明显高于远郊鲁家沟镇。退耕还林(草)政策对以农业为主导产业的远郊鲁家沟镇农村经济结构影响相对较小,近郊凤翔镇工业、服务业和商业餐饮业等非农产业占农村经济总收入的比重随着农业收入比重的降低而有所提高;(3)退耕还林(草)政策的实施带动了该区种植业结构的转变,这在一定程度上缩小了凤翔镇和鲁家沟镇农村集体收入之间的差距;(4)退耕还林(草)政策实施过程中,梯田面积、玉米和马铃薯等秋粮作物种植面积的增加提高了农村居民纯收入。研究认为退耕还林(草)在实施过程中需考虑地域差异,依据区域经济发展状况进行相应调整,在推动种植业发展的同时还应兼顾林业、牧业和一些非农产业发展,最终实现生态环境恢复与农村经济的协调发展。     

Experiments on integration of chemical and biological control of aphids on brussels sprouts

Two field experiments were made to test whether natural enemies would take over control of brussels sprouts aphids at the time when protection from a selectively acting, soil-applied systemic insecticide, menazon, began to fail. The natural enemies, notably Syrphidae, proved ineffective against Brevicoryne brassicae L. despite advantages given by the insecticide and by close planting, which greatly increased the ratio of numbers of syrphid eggs and larvae to aphids. Thus, development of the aphid population was little altered when infested plants were kept free of most natural enemies by hand removal. I lb/acre (1–12 kg/ha) of menazon applied as spot treatments to the soil at planting-out time decreased the number of overwintering parasite mummies by 70 % but such ‘mortality’ was compensated for by decreased mortality from hyperparasites and other causes, so the numbers of adults of the primary parasite Diaretiella rapae (McIntosh) which emerged in the spring were similar to those from untreated plots. Soil cultivation in winter drastically decreased the numbers of emerging adult primary parasites, hyperparasites and syrphids. The menazon treatment designed for integrated control (1 lb/acre) seemed too unpredictable in action, e.g. less effective in dry than in damp conditions, to provide the hoped-for chemical control needed until natural enemies became abundant. Menazon at 4 lb/acre (4·48 kg/ha) protected the crop throughout the growing season and bioassays showed that menazon or its toxic derivatives continued to occur in leaves during cool periods in winter and also in the following April-May nearly 1 year after application. The same amount of menazon per unit area of crop was less effective on 1 ft 6 in (45·6 cm) spaced than on 3 ft (91·2 cm) spaced brussels sprouts plants.     

Effects of skin spot (Oospora pustulans) on potatoes

King Edward and Majestic seed potatoes selected as ‘clean’ (macroscopically symptomless), moderate and severe according to the extent of skin spot were planted in field experiments at Rothamsted between 1964 and 1968. Usually crops from ‘clean’ and moderately infected seed did not differ detectably in growth or yield. Plants from severely infected seed tubers emerged more slowly, had fewer stems and yielded less (King Edward 20 %, Majestic 13 %). Seed infection also affected tuber size distribution; severely infected seed of King Edward yielded almost 4 tons/acre less of 1 1/4-2 1/4 in tubers and Majestic, 1 ton/acre less of these and 2 tons/acre less 2 1/4-3 1/4 in tubers. However, the total yield from diseased seed stocks was only slightly less (King Edward, o-6 ton/acre and Majestic o-8 ton/acre) than the yields from the ‘clean’ tubers selected from them. Seed severely infected by Oospora pustulans often increased infection of the progeny tubers, and usually decreased their infection by Rhizoctonia solani and sometimes by Helmintho-sporium solani. Another series of experiments compared King Edward seed tubers classified according to the number of live eyes showing in March. Seed with one, two, three and more live eyes yielded equally. About half the tubers without live eyes in March eventually produced plants, but late, with few stems and giving only half the yield of seed with three or more live eyes. Surprisingly, the progeny tubers from seed without live eyes were least infected by O. pustulans, R. solani and H. solani. Progenies of King Edward and Majestic seed from a common source grown on seven widely separated farms were infected more in 1963 than in 1964, but in each year infection differed widely between farms. Often where O. pustulans was common, R. solani was scarce and vice versa. By contrast, when King Edward stocks very differently infected by O. pustulans were grown at Rothamsted their progenies were almost uniformly infected by O. pustulans and R. solani.     

The systemic, holistic, interdisciplinary and participatory (SHIP) approach supports the conservation program of medicinal plants in Bali

Development process brings the positive as well as negative impacts. Among others, the negative impacts include the extinction of some medicinal plants. The research issue is what strategy can be used for preserving the medicinal plants while little attention is given to them. A research action was thus started for preserving and conserving these plants. Methods used were participatory observation, field surveys, and demonstration-plots. The action consisted of: an awareness program, a preparation phase and the establishment of a park of medicinal plants. In doing that, the Systemic, Holistic, Interdisciplinary and Participatory (SHIP) approach was applied. Up to now, the results found are: 1) the awareness program was conducted several times; 2) two pieces of lands were provided from the provincial government of Bali and from the local community; 3) the field surveys identified about 200 kinds of medicinal plants in the house yards, government offices, hotels and median strips of roads; 4) in the traditional medicine texts (lontar), more then 500 kinds of medicinal plants were found to be cited; 5) the medicinal plants were classified into wooden trees, shrubs, grasses, watery plants, epiphytes and parasitic plants. It is concluded that preserving and conserving the medicinal plants in Bali is urgent and that there is a willingness to do that with the active support of the stakeholders. It is encouraging that good examples have already been established in Ubud, Tampaksiring and Karangasem. Therefore, it is recommended to establish a medicinal plants park in Bali since it will have multiplier effects.