共查询到20条相似文献,搜索用时 140 毫秒
1.
The adequate use of sewage sludge in silvopastoral systems could enhance positive relationships between pasture and trees
to increase farm incomes at medium, short and long term. The main aspects related to adequate sewage sludge use as a fertiliser
are dose and timing of application, once heavy metal concentrations have been taken into account. This paper aims to evaluate
the date and dose of sewage sludge applications on soil (KCl pH, soil organic matter), pasture production and tree growth
after the establishment of a silvopastoral system with Pinus radiata D. Don developed on sandy soils with an initial pH of 5. It is concluded that the contribution of sewage sludge does not
modify the soil conditions in a consistent manner, but cause detectable edaphic improvements depending on the climatic conditions,
the results of which are manifested in enhancement of pasture and trees. The application of high doses of sewage sludge is
the best option within those studied, as tree growth and pasture production tend to be increased. There are no clear effects
with regard to the date of application, but if the desire is to increase pasture production during the spring season, the
sewage sludge will be applied in the first of the application dates, whereas the greatest growth in the diameter of trees
is produced in the plots fertilised in February, although the date of application does not appear to have a clear effect on
their growth in height. 相似文献
2.
M. L. López-Díaz M. R. Mosquera-Losada A. Rigueiro-Rodríguez 《Agroforestry Systems》2007,70(1):91-101
In recent years, in the European Union, sewage sludge production has been increased as a result of EU policy (European directive
91/271/EEC). Organic matter and nutrient sewage sludge contents, principally nitrogen, indicate it can be used as fertilizer.
The objective of the experiment was to compare the effect of no fertilization, three doses of sewage sludge, with or without
liming, and the fertilization usually used in the region applied over a period of 3 years on pasture production and tree growth
in a silvopastoral system. The experiment was conducted in the northwest of Spain. The soil was very acid (soil pH = 4.5)
and had very low nutrient levels, especially P, that is related to site index. It was sown with a grass mixture (25 kg ha−1 of Lolium perenne L. 10 kg ha−1 of Dactylis glomerata L. and 4 kg ha−1 of Trifolium repens L.) in Autumn 1997 under a plantation of 5-year-old Pinus radiata D. Don at a density of 1,667 trees ha−1. Liming and sewage sludge fertilization increased soil pH and reduced saturated aluminium percentage in the interchange complex
(Al/IC) in the soil, coming up the effect before with liming. Medium and high sewage sludge doses increased pasture production
in the two first years. In a silvopastoral system, positive tree growth response to different fertilization treatments depended
on tree age, initial soil fertility, soil pH, the relationship of competition with pasture production and previous liming
application. 相似文献
3.
Silvopastoral systems, which combine tree and pasture production, are more complex ecosystems than exclusively agronomic systems. Good silvopasture management should seek to increase positive interactions (or synergies) and reduce negative interactions among system components (soil, trees, grass and cattle) to increase global system productivity. Tree growth and pasture production within such systems can be optimized through appropriate species selection and fertilization. The aim of the present study, carried out over the course of 3 years, was to compare how traditional fertilisation, sewage sludge dose, and potassium affect pasture-tree competition, botanic composition and tree growth in a silvopastoral system located on agricultural land during the early years of system development. The addition of potassium is recommended for improving tree growth in silvopastoral systems with slightly acidic soil, especially if the pasture has high legume content. White clover is a good choice of species for silvopastoral systems because it promotes tree growth. Our study revealed that pasture production improved when sewage sludge was used as a fertiliser, but annual production was still more strongly dependent on weather conditions. 相似文献
4.
Kevin Lombard Mick O’Neill Robert Heyduck Blake Onken April Ulery John Mexal Adrian Unc 《Agroforestry Systems》2011,81(1):45-56
Composted sewage sludge (biosolids) supply plant available Fe and may represent a sustainable alternative to more costly chelated
Fe fertilizers currently used to supplement nutrition in hybrid poplar test plots of elevated soil pH. To test the response
of poplars, field plots were amended with composted biosolids at two agricultural rates: 22.75 and 44.5 Mg ha−1. Iron EDDHA served as a fertilizer check and control plots received no amendment. The hybrid poplar OP-367 (Populus deltoides × P. nigra) was planted on a 3.6 m grid spacing. Significant amounts of P and Fe originating from the sewage treatment process were
detected in soils 13 months after amending. Chlorosis evaluated with a SPAD-502 meter, showed that poplars amended with biosolids
remained the least chlorotic and had greater tree growth when compared to Fe EDDHA and control plots during two growing seasons.
Biosolids show promise as a cost effective alternative for the remediation of Fe chlorosis in hybrid poplar agroforestry plantations
and present new opportunities in northwestern New Mexico for municipalities seeking solid waste land disposal options. 相似文献
5.
Manuel Madeira António Fabião Marta Carneiro 《European Journal of Forest Research》2012,131(3):583-596
Effects of harrowing and fertilisation on tree growth, understory vegetation, forest floor litter and soil properties were
studied in a field experiment installed in a 5-year-old first rotation eucalypt plantation. The treatments were harrowing
(H), fertilisation (F), harrowing and fertilisation (HF) and a control without any treatments (C), with four replicates. Tree
growth, root mass, tree nutrition status, understory vegetation, mass of forest floor litter and soil physical and chemical
properties were monitored till the end of the rotation (stand was 14-year old). Effects of treatments on tree growth, root
mass and timber production were not significant. Root nutrient concentration differed between treatments only few months after
the beginning of the experiment, while differences regarding specific root length and area were observed during the first
year. Harrowing (H and HF) led to significantly smaller biomass of understory vegetation (<13.4 g m−2) than other treatments (33−61 g m−2) during the first 3 years, but at the end of the experiment differences were less important. Forest floor litter mass after
3 years and at the end of the experiment were similar among treatments. Soil bulk density significantly decreased by harrowing
(H and HF treatments), but 16 months after treatments were similar. Although soil chemical properties were not significantly
affected by treatments, a decrease in base cations occurred during the rotation period. Fertiliser application is a questionable
practice under the economic point of view, whereas harrowing can reduce the fuel load only during a short period, without
negative effects on productivity and soil quality. 相似文献
6.
We have evaluated the effects of improving substrate fertility on the growth and reproduction of a P. halepensis plantation in a restored limestone quarry on a stony calcareous regolith (R plots). The natural substrate was supplemented
by adding a 0.2 m layer of a fine textured soil (RS plots) or a sewage sludge amended soil (RSS plots). The treatments were
performed when the pines were 7 years old, and tree growth (height and trunk and canopy diameter) was monitored over the subsequent
12 years. The reproductive status of the trees was also measured when the pines were 20 years old. Tree growth was proportional
to the amount of soil nutrients: 12 years after treatment the mean height of the R, RS and RSS trees was 1.5, 3.1 and 6.2 m
respectively and growth increases over the baseline were 76, 264 and 632%. The treatment also affected the age of onset of
reproduction (15, 11 and 9 years, respectively), the average number of cones per tree (12, 43 and 61), and the amount of seeds
per cone (37, 52 and 72), but did not modify the germination percentage of pine seeds (ca 71.5%). Soil organic carbon increased
proportionally to the vegetation development, contributing to carbon sequestration. These results suggest that improving the
nutritional status of the soil not only improves the growth of trees, but it also ameliorates their reproductive ability (earlier
reproduction onset and larger seed crop size). Implications for soil restoration through afforestation are also discussed. 相似文献
7.
Hua-Feng Wang María Vanessa Lencinas Cynthia Ross Friedman Xiao-Ke Wang Jiang-Xiao Qiu 《New Forests》2011,42(1):101-116
Biodiversity in managed plantations has become an important issue for long-term sustainability of ecosystems. The environmental
effects of plantations comprised of fast-growing introduced trees have been vigorously debated. On one hand, monocultures
have been said to exhaust resources, resulting in decreased biodiversity. Conversely, it has been stated that monocultures
may favor regeneration of undergrowth plants from surrounding forests, increasing biodiversity. In order to clarify the effects
of planting Eucalyptus trees on species composition, diversity, and functional type of understory vegetation in Yunnan province, a field trial was
implemented to compare Eucalyptus plantations (EPs) with two other local current vegetation types (secondary evergreen forests (SEs), and abandoned farmlands
(AFs)). Each vegetation type was sampled in each of three elevational ranges (low = 1,000–1,400 meters above sea level (masl),
medium = 1,400–1,800 masl, and high = 1,800–2,200 masl). Sample sites within each elevational range had similar environmental
characteristics (slope, aspect, etc.). Thus, we sampled three vegetation types at each of three sites at each of three elevations
for a total of 27 plots. We calculated relative abundance and importance value of species and diversity indexes to evaluate
differences among local current vegetation types and elevational ranges, employing multivariate ordination analyses and other
methods such as Analyses of Variance (ANOVA) and Indicator Species Analysis. We found that fast growing introduced Eucalyptus plantations led to reduced plant diversity in the study area, and that rare or threatened species were recorded almost exclusively
in the SE plots, being essentially absent from the EP and AF plots. The understory plant diversity did not correlate with
the altitude gradient significantly. Eucalyptus plantations (EPs) have a simpler community structure than that of either secondary evergreen forests (SEs; similar to natural
state) or abandoned farmlands (AFs). No variable significantly explained variation of the understory shrub layer, but soil
moisture-holding capacity and overstory coverage were significant in explaining variation of the understory herb layer, suggesting
that the study of soil physical properties is necessary for better understanding of their importance in Eucalyptus plantations and other local current vegetation types. 相似文献
8.
Moses Imo 《Agroforestry Systems》2009,76(2):265-273
Lack of empirical data on the effects of the taungya system on establishment and early growth of softwood plantations have partly contributed to controversial decisions regarding
the continued suitability of the system for plantation establishment in Kenya. This study examined effectiveness of taungya systems of forest plantation establishment using Cupressus lusitanica and Pinus patula trees with Zea mays (maize) as a test intercrop on two contrasting site types (deep and shallow soils) in Mt. Elgon forest, western Kenya . Four
treatments were evaluated in each site: trees with or without weed control, trees intercropped with maize, and sole maize.
Results showed that tree survival, growth and nutrient uptake, and maize growth and yield were higher in the deep soil site
than the shallow site. The t
aungya system improved tree survival and growth, effects being greater in the deep than the shallow soil site. Both Cupressus lusitanica and Pinus patula trees had the same effects on maize growth and yield, reducing maize growth by 41–48% in the deep soil sites, and by 16–26%
in the shallow site. Vector nutrient analysis and vector competition analysis of the treatment effects on growth and nutrient
uptake of the trees and the maize crop suggested competition for N on the deep soils, but competition for K and P on the shallow
soils. The study has demonstrated the applicability of graphical vector competition analysis in diagnosing tree–crop interactions
in agroforestry. 相似文献
9.
This study presents empirical data on regeneration and growth of understory trees and constructs simple models for predicting
these characteristics at various stand structure and post-thinning standing volume levels. The field experiment was established
on a grass/herb mineral soil site in central Finland. Regeneration and understory tree growth data were collected from 24
Norway spruce (Picea abies L.)-dominated mixed substands. Seedlings with heights from 5 to 130 cm were measured in 1996 and 2007. In addition, the annual
height growth of Norway spruce seedlings was measured in 2007. The spatial pattern of the substands varied from clustered
to regular with a decreasing standing volume. Stand complexity was uniform across the range of standing volume. In the 2007
survey, the amount of Norway spruce regeneration increased from approximately 400 to 5,000 seedlings ha−1 when the post-thinning standing volume level was reduced from 230 to 90 m3 ha−1, respectively. Nearly no seedlings were found when the standing volume was over 300 m3 ha−1. The annual diameter increment in Norway spruce understory (dbh < 5 cm) trees decreased, on the average, from 2.3 to 0.3 mm
with an increase in the standing volume level from 90 to 340 m3 ha−1, respectively; their height growth showed also a decreasing trend when the standing volume increased. The results indicated
that a post-thinning standing volume lower than 150 m3 ha−1 with a regular overstory spatial structure provides a suitable environment for regeneration and growth of Norway spruce understory
trees in the studied forest type. 相似文献
10.
Seedling growth response of two tropical tree species to nitrogen deposition in southern China 总被引:2,自引:0,他引:2
Seedling growth response of two tropical tree species (Schima superba and Cryptocarya concinna) to simulated N deposition was studied during a period of 11 months. One-year-old seedlings were grown in forest soil treated
with N as NH4NO3 at Control–no N addition, N5–5, N10–10, N15–15, and N30–30 g N m−2 year−1. The objective was to examine the effects of N addition on seedling growth and compare this effect between the two tropical
tree species of different species-N-requirement. Results showed that both species responded significantly to N addition and
exhibited positive effect to lower rate of N addition and negative effect to higher rate of N addition on growth parameters
(height and stem base diameter, biomass production, and net photosynthetic rate). The highest values were observed in the
N10 plots for S. superba and in the N15 plots for C. concinna, but the lowest values were observed in the N30 plots for both species. However, the reduction in the N30 plots was more
pronounced for S. superba than for C. concinna relative to the control plots. Our findings suggest that response of seedling growth of tropical tree species to atmospheric
N deposition may vary depending on rate of N deposition and species-N-requirement. 相似文献
11.
Seed limitation of desired indigenous species has constrained the succession of established plantations from an early successional
stage, to more natural forests in South China. Because of its low cost and time-saving advantages, direct seeding has been
considered a useful method in forest regeneration. To improve our understanding of whether and how direct seeding can lead
to the establishment of indigenous tree species, we carried out an experiment in four typical plantations (eucalyptus, mixed-native,
mixed-legume, mixed-conifer) and a shrubland in South China. We also tested the effect of understory vegetation and litter
removal on seedling establishment and growth. Seeds of three indigenous tree species (Castanopsis chinensis, Cryptocarya chinensis, and Psychotria rubra) were sown with understory vegetation and litter either retained or removed. Seedling emergence, survival, and growth were
recorded for 21 months. We found that conditions that favored seedling emergence often differed from those that favored seedling
survival. While the removal of understory vegetation and litter did not influence the final seedling establishments for all
the three introduced species, growth of Psychotria rubra was influenced at several sites. Seed mass was positively correlated with seedling emergence and subsequent growth. The large-seeded
Castanopsis chinensis showed higher emergence and growth than the intermediate-seeded Cryptocarya chinensis or the small-seeded Psychotria rubra. Seedlings of Castanopsis chinensis grew better in plant communities with high understory light penetration and high soil exchangeable potassium. Growth of P. rubra seedlings decreased significantly with soil hydrolyzed nitrogen. In conclusion, direct seeding can be useful for the establishment
of indigenous tree species into plantations and shrubland. Optimizing early seedling establishment and growth will require
the selection of suitable native species for improving seedling establishment in different plantations. Additionally, understory
vegetation and litter and fertilizer should be properly managed to enhance the establishment of certain indigenous tree species. 相似文献
12.
Atsushi Sakai Takeshi Sakai Shigeo Kuramoto Shigeho Sato 《Journal of Forest Research》2010,15(5):316-327
To profile secondary succession after clearcutting a conifer plantation, we examined the composition of the soil seed bank
and the process of vegetation recovery after clearcutting a mature Hinoki (Chamaecyparis obtusa) plantation in southwest Japan. We set up two study plots and collected 25 and 26 soil samples (each 20 cm × 30 cm × 5 cm
depth), respectively, in April 1999, before clearcutting. Using the seedling emergence method, we detected 500–839 buried
viable seeds m−2 in 42–44 species. Soil seed banks in both plots contained typical pioneer species but few late-successional species. After
clearfelling the plantation in June 1999, we censused seedling establishment for 4 years and the composition of the vegetation
for 6 years. More than half of the seedlings emerged in the second year, suggesting that the timing of clearcutting is possibly
critical to seedling establishment. Nineteen plant species disappeared after clearcutting, 40 species were retained and 43
species newly emerged after clearcutting. Most of the newly emerged species were pioneer species which originated in the soil
seed bank. Seven of the pioneer species, as typified by Rubus crataegifolius, showed clonal growth from the third year after clearcutting. Japanese serow browsed the seedlings of major pioneer species,
possibly affecting the process of secondary succession. Late-successional species such as Abies firma declined in coverage or disappeared after clearcutting. Our results suggest that the soil seed bank makes a major contribution
to vegetation recovery after clearcutting, but possibly not to restoration of the late-successional species. 相似文献
13.
The use of municipal sewage sludge as a fertiliser could be a more adequate means of disposal of this residue than its transport to the dump. The objective of this experiment was to evaluate the effects of different doses of sludge and sowing a mixture of cocksfoot (Dactylis glomerata) and clover (Trifolium repens) on pasture production, botanical composition of the pasture, forage quality, and changes in soil chemical properties. Treatments applied were: (1) no fertilisation (L0), (2) fertilisation with 26 Mg ha–1 of sewage sludge with no sowing (L40), (3) fertilisation with 26 Mg ha–1 of sewage sludge and sowing with 25 kg of Dactylis glomerata L. cv Artabro (Dg) and 3 kg Trifolium repens cv Huia per hectare and (4) 52 Mg ha–1 of sewage sludge with no herbage sowing (L80). Plots were established in a silvopastoral system with Pinus radiata D. Don at a density of 1666 trees ha–1 (3 × 2 m). The improvement of soil fertility due to organic fertiliser application and the use of Dactylis glomerata increased the production and quality of pasture as well as reduced the risk of fire and erosion, as grasses dominated shrubs. Fertilisation with sewage sludge in soils of acid origin increased the concentration of copper in the pasture and, if cocksfoot was not sown, the levels of this element exceeded the maximum tolerable dietary levels for sheep. On the other hand, fertilisation also increased the levels of zinc in pasture, but values were not above toxic limits for sheep, horses and cattle.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
14.
R. Houehounha H. T. Avohou O. G. Gaoue A. E. Assogbadjo B. Sinsin 《Agroforestry Systems》2010,78(2):115-125
Daniellia oliveri is an indigenous tree with multiple coppicing that is harvested as firewood by local people from savannas and traditional
fallows in West Africa. We investigated the effects of periodic weed removal on D. oliveri resprouting and growth in traditional fallows and its use for firewood production by smallholder harvesters. Protected plots
were established in D. oliveri dominated fallows at four sites with contrasting soil types. The weedy control plots experienced periodic fires and grass
competition. Sizes of firewood logs were surveyed on local markets and used to estimate the quantity of marketable firewood
for each treatment. The species sprouted vigorously, forming pure stands. Leading shoot density on weed-free plots was three
times higher, reaching 7,250 ± 454 shoots ha−1 34 months after land clearance when compared to 2,425 ± 215 shoots ha−1 on weedy plots. The weed removal treatment increased shoot height from 18 to 34 months after land clearance, while shoot
diameter was not affected. After 24 months, 50% of the shoots were of marketable size for the weedy treatment, while this
was reached at 18 months for the weed-free treatment. 相似文献
15.
Incorporating cover crops into Christmas tree plantations may potentially improve soil fertility, tree growth and quality
and be an alternative to commercial nitrogen (N) fertilizers. However, cover crops may compete with the trees for water and
other nutrients than N. This study was carried out to assess whether soil fertility, tree survival and growth could be improved
by incorporating leguminous and non-leguminous cover crops into the Fraser fir (Abies fraseri) production system. Dutch white clover (Trifolium pratense), alfalfa (Medicago sativa) and perennial ryegrass (Lolium perenne) were grown in a newly established Fraser fir plantation using two cover crop management practices; no banding (NB) by growing
each cover crop throughout the entire plot and banding (B) by creating a 61 cm-wide bare zone centered on the tree rows. A
conventionally-managed system (CONV) was used as a control. The cover crop aboveground biomass and N content were assessed.
Soil available N (NO3
− and NH4
+) and N mineralization were measured at 0–15, 15–30 and 30–45 cm soil depths. Tree survival, growth, photochemical efficiency
of photosystem II (Fv/Fm), branch water potential (Ψw) and foliar nutrients were also evaluated. Biomass production was as high as 13.9, 10.2 and 5.9 Mg DM ha−1 year−1 for clover, alfalfa and ryegrass, respectively. Cover cropping increased soil available N by 1.5- and 2.2-fold relative the
CONV in the top soil layer in 2007 and 2008, respectively. Tree seedling survival and growth in the B and CONV systems were
similar. In contrast, NB treatments resulted in poor seedling survival and growth relative to the B and CONV plots. Plant
Ψw and Fv/Fm decreased significantly for A. fraseri seedlings on the NB treatments relative to their counterparts on the B and CONV plots. However, cover cropping had marginal
effects on foliar nutrients. Cover cropping with banding can be an efficient strategy for maintaining productivity in Fraser
fir Christmas plantations. 相似文献
16.
Intercropping alleys in agroforestry provides an income source until the tree crop produces harvestable yields. However, cultivation
of annual crops decreases soil organic matter and increases soil erosion potential, especially on sloping landscapes. Perennial
crops maintain a continuous soil cover, increase water infiltration, reduce soil erosion, and improve overall soil quality.
The objective of this on-farm study was to assess the effects of a perennial legume, kura clover (Trifolium ambiguum M. Bieb.), on soil quality in a recently established pecan (Carya illinoinensis Wangenh. C. Koch) orchard. The pecan-kura clover agroforestry practice was established on deep loess soils of the Missouri
River hills landscape. These silt loams are on 2–20% slopes and can be highly erosive. Kura clover, introduced as the alley
crop 5 years after pecan planting, was selected based on its perennial growth habit, nitrogen-fixing ability, winter hardiness,
high forage quality, and soil conservation properties. Kura clover was seeded in 2001 and harvested for hay annually beginning
2003. Soil quality indicators of total organic C, total N, water-stable aggregates, and selected soil enzymes were determined
on surface soil samples collected annually after kura clover establishment. Soil organic C and activities of soil enzymes
increased compared with cultivated and grass pasture control soils by the eighth year of establishment. Water-stable aggregation
improved by 50% and surface soil shear strength improved significantly (P < 0.05) in alleys compared with control sites. Results illustrate that kura clover as the alley-cropped component improved
soil fertility and biological activity through increased organic matter and improved soil structure, and yielded high quality
forage valuable for the cattle-feeding operation. Kura clover maintained or improved soil quality, reduced soil erosion potential,
and benefited pecan growth by providing a source of soil nitrogen and improving soil structure for adequate water infiltration
and aeration. 相似文献
17.
James D. Haywood 《New Forests》2011,41(1):55-73
Restoring longleaf pine (Pinus palustris Mill.) over much of its original range requires artificial regeneration. In central Louisiana, USA, two fertilization levels—No
(NF) or Yes (F-36 kg/ha N and 40 kg/ha P) in combination with three vegetation treatments—Check, four prescribed fires (PF),
or multi-year vegetation control by herbicidal and mechanical means (IVM) were applied to container-grown longleaf pine plantings
in a grass savanna. After 10 years, P concentration in longleaf pine foliage was less on NF plots than F plots, but fertilization
did not significantly affect tree stature. Survival was greater on NF plots than F plots, and so, NF plots were more productive
(NF—63 m3/ha and F—45 m3/ha). Pine trees on IVM plots (37 dm3/tree) were significantly larger than on Check and PF plots, which averaged 17 dm3/tree. Survival was better on IVM plots (88%) than PF plots (78%), which was better than Checks (58%). Consequently, IVM plots
were most productive (99 m3/ha), followed by PF plots (44 m3/ha), and lastly Checks (28 m3/ha). PF plots had greater grass cover (38%) than Check and IVM plots, which averaged 5%, whereas PF and IVM plots had less
understory arborescent cover (an average of 25%) than Checks (91%). A wildfire in March 2007 reduced pine survival by 22,
14, and 1 percentage points on IVM, Check, and PF plots, respectively. Seven months later, longleaf pine production had decreased
to 92 m3/ha on IVM plots while increasing to 55 m3/ha on PF plots and 30 m3/ha on Checks. Overall, the wildfire rejuvenated the herbaceous plant community. Grass cover on Check and IVM plots averaged
20% while grass cover on PF plots was 36%. Forb cover increased on all treatments from 2% before the wildfire to 13% seven
months after the wildfire. Understory arborescent cover decreased on Checks to 62% but increased slightly on PF and IVM plots
and averaged 30%. 相似文献
18.
This experiment was carried out in a mature (>100-year-old) eastern beech forest in the Eastern Black Sea Region (BSR) of
Turkey. The effects of experimental practices to control the woody plant Rhododendron flavum Don., including grubbing, manual cutting, and foliar and cut-stump spraying with imazapyr and triclopyr, were assessed on
understory and forest floor biomass and nutrients, as well as soil bulk density and nutrient content. The cut plots had 5,
15, and 38 times greater competing vegetation biomass than did the plots treated with triclopyr, grubbing, and imazapyr, respectively.
Because of the increased biomass, the amount of understory N, P, Ca, K, S, and Mg content on the cut plots was also substantially
higher when compared to the grubbed, imazapyr-treated, and triclopyr-treated plots. Triclopyr and imazapyr applications brought
about two- and threefold greater dead organic matter on the forest floor than did cutting and grubbing, respectively. As a
result, forest floor macronutrient contents on the imazapyr- and triclopyr-treated plots were significantly greater than on
the cut plots. Five years after treatments, soil bulk density at the 10–20 cm depth on the imazapyr-sprayed plots was about
14% higher than that on other treatments. Herbicides, especially imazapyr and grubbing were effective in controlling rhododendron.
Macronutrients stored in the rhododendron were released to the forest floor after vegetation was controlled with herbicides. 相似文献
19.
Pilar Mañas Elena Castro Pau Vila Jorge de las Heras 《European Journal of Forest Research》2010,129(4):521-530
Peat moss is gradually being replaced by other materials as a growing medium in forest nurseries due to economic and ecological
constraints. In this study, six different mixtures were tested, mixing peat moss (P) and pine bark (B) with digested sewage
sludge (S) activated sewage sludge (A) and paper mill sludge (M), as growing media for Pinus halepensis seedlings; three different waste doses were applied. Seed germination percentage, seedling growth and foliar nutrient content
after 1 year in a greenhouse and percentage survival after transplanting were recorded. The influence of base substrate (P
or B) on germination percentage changed in different ways according the type of waste. The order of the different applied
mixtures by suitability (germination rate and seedling growth) from best to worst was as follows: activated sludge with peat,
activated sludge with pine bark, sewage sludge with peat, sewage sludge with pine bark, paper mill sludge with pine bark and
finally paper mill sludge with peat. 相似文献
20.
M. Carneiro A. Fabião M. C. Martins C. Cerveira C. Santos C. Nogueira M. Lousã L. Hilário André Fabião M. Abrantes M. Madeira 《European Journal of Forest Research》2007,126(4):475-480
The aim of this study was to assess the effect of different slash management practices on understory biodiversity and biomass
in Eucalyptus globulus coppices in Central Portugal. The experiment consisted of four treatments: (a) removal of slash (R), (b) broadcast over the
soil (S), (c) as in S but concentrating woody residues between tree rows (W) and (d) incorporation of slash into soil by harrowing
(I). Understory vegetation was surveyed during 1–6, 9, and 10 years, the proportion of soil cover by plant species estimated,
and diversity and equitability indexes determined. Above ground understory biomass was sampled in years 2–6, 9, and 10. The
highest number of species in most years occurred in plots where slash was removed. Differences between treatments in the proportion
of plant soil cover were never significant, whereas differences in diversity index were only occasionally significant and
apparently related to the number of species. Thus, differences in the equitability index were not significant. Understory
biomass did not decrease during the rotation period, and was usually highest in R and I, and lowest in S, but not significantly
different. At the end of the rotation period, understory biodiversity indices and biomass were apparently independent of slash
treatment. 相似文献