Relative Height Growth Rate Research Articles

아왜나무와 종가시나무의 생육에 대한 지중매입형 컨테이너의 효과

This study was carried out to cultivate evergreen-leaved tree container seedlings having low cost of equipment and easy to control. Two species of V. odoratissimum var. awabuki and Q. glauca planting in respective underground container were showed survival rate above 90%. The Relative growth rates of height was good in non-treatment and root collar diameter was no significant difference between treatments. The T/R ratio was respectively 1.1, 1.0 in container type of F, G. and root's biomass products was more effective than others. A container type of F showed better Quailty index than others with 16.2 values. Q. glauca was higher T/R ratio in root development than shoot and the quality index was high in container type of E, D with 4.0. 3.5, respectively. On the basis of the results obtained in this study, we can concluded that the underground container type was suitable to F in V. odoratissimum var. awabuki and to D or E in Q. glauca.

Provenance variation in survival, growth and dry matter partitioning of Parkia biglobosa (Jacq.) R.Br. ex G.Don seedlings in response to water stress

The effects of drought stress on growth and dry matter partitioning of seven provenances of Parkia biglobosa were assessed in a nursery experiment. Three different water regimes were applied: soil high, medium and low water content (HWC, MWC and LWC) corresponding respectively to 100, 75 and 50 % of field capacity. A split-plot experimental design was applied with the provenance as main plot and the water regime as sub-plot, replicated three times. Each provenance was represented by 30 seedlings in each replication, corresponding to three test periods with ten seedlings each (6, 12 and 18 months after water stress started). There were significant interactions between provenance and water regime for survival rate and the relative growth rates of diameter and height. After 18 months, the dry matter mean was 20.00 ± 0.65 g for the HWC regime, 11.50 ± 2.90 g for the MWC regime while all plants in the LWC regime died. After 6 months, the accumulated water use efficiency (WUE) showed significant differences between water regimes, but not between provenances. Seedlings from the LWC regime showed higher WUE than those from the MWC regime. However, the HWC regime displayed the highest mean value of WUE. Despite differences between provenances, it was not possible to clearly separate them according to the geographical position or climatic parameters, based on the growth performance or both fresh to dry weight and shoot to root dry weight ratios.

Competitive Interactions of Garlic Mustard (Alliaria petiolata) and Damesrocket (Hesperis matronalis)

AbstractCompetitive interactions between native plants and nonnative, invasive plant species have been extensively studied; however, within degraded landscapes, the effect of interspecific interactions among invasive plants is less explored. We investigated a competitive interaction between two sympatric, invasive mustard species that have similar life history strategies and growth forms: garlic mustard and damesrocket. Greenhouse experiments using a full range of reciprocal density ratios were conducted to investigate interspecific competition. Garlic mustard had a negative effect on the final biomass, number of leaves, and relative growth rate in height of damesrocket. Survival of damesrocket was not negatively affected by interspecific competition with garlic mustard; however, garlic mustard showed higher mortality because of intraspecific competition. These results indicated that although garlic mustard has been observed to be the dominant species in this landscape, it may not completely outcompete damesrocket in all situations. Studies of invasive species in competition are important in degraded landscapes because this is the common situation in many natural areas.

Effects of soil nutritional status on seedling nursery performance of Arizona cypress (Cupressus arizonica var arizonica Greene) and Medite cypress (Cupressus sempervirens var. horizantalis (Mill.) Gord)

The present research was carried out to determine the influence of different combinations of organic matter as growing media on seed germination, survival, growth, biomass and performance of needle-leaved Arizona cypress (Cupressus arizonica var arizonica Greene) and Medite cypress (C. sempervirens var. horizantalis (Mill.) Gord) seedlings in Koloudeh nursery, located in Amol city (North of Iran). Seeds were sown in plastic pots as randomized completely block design (RCBD) with four replications atfour different soil treatments, including: T1) nursery common soil (control), T2) control soil: cattle manure (5:1), T3) control soil: decomposed litter (5:1), T4) control soil: cattle manure: decomposed litter (5:1:1). The results after one year showed that seedlings of both species grown on T4 obtained better germination percent, survival, shoot height, collar diameter, seedling vigor index and Quality Index (QI). Greatest relative growth rate (RGR) of height and diameter were achieved on organic matter treatments. In most of the studied attributes, response of C. arizonica was better than C. sempervirens, showing the different biological requirements of these species. From the study, it is concluded that the increased of soil nutrient can be useful in seedling production of both species. Key words: Biomass, Cupressus arizonica, Cupressus sempervirens, organic matter, quality index, vigor index.

Spatial and temporal heterogeneity of light and soil water along a terra firme transect in Amazonian Ecuador: effects on tree seedling survivorship, growth, and allocation

To better understand the availability of plant resources on the forest floor in the Amazon and also to show the effect of their heterogeneity on tree seedlings, I described the spatial and temporal variation of light and soil water along a 100 m transect in a terra firme forest for 6 months and recorded responses of three tree species planted on that transect after 1 year’s growth. I found that (i) the spatial heterogeneity across the transect was greater than the temporal heterogeneity at any given microsite on the transect for both light and water and there was a positive correlation between them, (ii) Couepia obovata Ducke, the largest seeded and the only subcanopy tree, survived the best and showed both the largest relative height growth rate (RHGR) and the largest specific leaf area (SLA), while among the two early successional trees, Tapirira guianensis J.B. Aublet had the largest leaf area ratio (LAR) and the largest leaf mass ratio (LMR) and Duguethia spixiana Mart. had the largest root to shoot ratio (RTOS), (iii) for T. guianensis, SLA increased with increasing light and soil water potential predicted both increasing LMR and decreasing RTOS with increasing soil water, and (iv) soil water potential could also predict increasing LAR with increasing water for D. spixiana and, for C. obovata, soil water potential predicted more survivorship, LMR, and RHGR but less RTOS, all with increasing soil water. I conclude that some subcanopy trees may survive and grow more than open-canopy trees when presented with water stress in the forest understory and that within the ranges of light and soil water sampled here, plants responded more to spatial variation in water compared with light.

Identification of antibiosis and tolerance in rice varieties carrying brown planthopper resistance genes

Brown planthopper (BPH) [Nilaparvata lugens (Stål) (Hemiptera: Delphacidae)] is a major pest in rice [Oryza sativa L. (Poaceae)] production. Identification of resistance genes and development of BPH-resistant varieties is an economical and effective way to control this pest. In this study, BPH honeydew excretion, survival rate, and emergence rate were used as indicators to detect the antibiotic level, whereas the relative growth rates of plant height (RH) and fresh weight (RW), and the number of days until yellowing were used to identify the level of tolerance to BPH in rice varieties. Rice varieties Swarnalata and B5, which showed high levels of antibiosis and tolerance to BPH, thus were highly resistant in the seedling bulk test; Mudgo and T12, which showed moderate resistance to the insects, had a high level of tolerance and moderate antibiosis to BPH. Varieties Rathu Heenati, ARC 10550, and Chin Saba were identified to be susceptible to BPH, showing a moderate level of tolerance and no antibiosis. In comparison to the evaluation methods of BPH resistance, the honeydew excretion and survival rate could be used to detect the antibiotic level, and the RH, RW, or leaf yellowing days could be employed as indicators to evaluate the rice varieties’ tolerance. Overall, a combined application of these indicators can effectively identify the levels of antibiosis and tolerance to BPH in rice varieties, and BPH-resistance levels of the varieties were mainly determined by the antibiosis level. The results should help in understanding BPH-resistance categories of rice varieties and for resistance breeding.

Tropical tree seedling growth responses to nitrogen, phosphorus and potassium addition

Summary1. Nutrients are a critical resource for plant growth, but the elements limiting growth in tropical forests have rarely been determined.2. We investigated the influence of nitrogen (N), phosphorus (P), potassium (K) and micronutrients on seedling biomass and nutrient allocation in a factorial nutrient fertilization experiment in lowland tropical forest at the Barro Colorado Nature Monument, Panama. We also measured 8 years of herbivory and growth for 1800 seedlings. We sought to determine the identity of limiting elements and possible nutrient interactions.3. The five study species were Alseis blackiana, Desmopsis panamensis, Heisteria concinna, Sorocea affinis and Tetragastris panamensis. Plants grew in deeply shaded understorey with a mean canopy openness of 4.9% (±0.7%; 1 SE).4. Tissue N concentration increased by 11% with N addition. Tissue P concentration increased by 16% with P addition. Tissue K increased by 4% with K addition. K addition reduced root‐to‐shoot biomass ratio. There was no significant effect of fertilization on specific leaf area or leaf area ratio.5. The proportion of leaves damaged and the mean level of damage by herbivory increased with P and K addition and showed a significant P × K interaction.6.7ensp;Across all species and years, relative growth rate of height increased with K addition and with N and P in combination. Relative growth rate of leaf count trended 8.5% higher with K addition (P = 0.076).7. We also added micronutrients in a parallel experiment. There was no effect of micronutrient addition on any seedling parameter.8. Synthesis. K addition affected seedlings by enhancing tissue nutrient concentration, increasing herbivory, reducing root‐to‐shoot biomass ratio and increasing height growth. Additional effects of N or P on tissue chemistry, herbivory and growth offer support for the multiple limiting resources hypothesis. Our results suggest that seedling growth is limited by nutrients, especially K, even under highly shaded conditions in this lowland tropical forest.

Effects of sediment burial disturbance on seedling emergence and growth of Suaeda salsa in the tidal wetlands of the Yellow River estuary

A greenhouse study was conducted to determine the effects of sediment burial on seedling emergence and growth of Suaeda salsa (L.) Pall. (Chenopodiaceae), a pioneer species in the tidal wetlands of the Yellow River estuary. From April to June in 2009, seeds of S. salsa were artificially buried at 0, 1, 2, 3, 4, 6 and 8 cm depths in plastic pots filled with unsterilized sediment. Results showed that the percent emergence, emergence time, seedling height, absolute height growth rate, relative height growth rate, stem diameter, number and length of branch, hypocotyl length and dry mass were significantly affected by burial depth. The percent emergence of seedlings had a significantly negative correlation with burial depth. Seedling emergence occurred from a maximum depth of 6 cm with most seedlings emerging from 0 cm depth. No seedlings emerged from 8 cm depth. The shortest emergence time occurred at 0 cm burial depth and seeds buried at 6 cm took significantly longer to emerge than those at other depths. With increasing burial depth, there was a stimulatory effect on seeding height, number and length of branch, stem diameter and dry mass, and simultaneously, the leaf: mass ratio increased, while stem: mass ratio decreased. The experiment also indicated that sediment burial disturbances could stimulate the hypocotyl below sediment to form adventitious roots, and the formation of larger root system would probably enhance seedling establishment, reflecting that the S. salsa seedlings had special adaptive strategy to the rapid sediment burial in the tidal wetlands of the Yellow River estuary.

Lianas escape self-thinning: Experimental evidence of positive density dependence in temperate lianas Celastrus orbiculatus and C. scandens

Abstract The neighborhood density of plants strongly affects their growth, reproduction, and survival. In most cases, high density increases competition and negatively affects a focal plant in predictable ways, leading to the self-thinning law. There are, however, situations in which high densities of plants facilitate focal plant performance, resulting in positive density dependence. Despite their importance in forest gap dynamics and distinctive growth form, there have been very few studies of the effect of density on lianas or vines. We grew an invasive (Celastrus orbiculatus) and a native (Celastrus scandens) liana species together in three different density treatments, while also manipulating the light and support availability. We found that across treatment conditions, C. orbiculatus always out-performed C. scandens, showing greater relative growth rate in height and diameter, greater biomass and higher survival. Both species responded similarly to the density treatments: with plants in high density not showing a decrease in relative height growth rate compared to medium density. Aboveground biomass for C. scandens was not affected by density, while for C. orbiculatus, the most massive plants were growing in medium density without support. More surprisingly, survival analysis indicated that the two species both had significantly lower mortality rates in the highest density treatment; this trend held true across the other treatments of light and supports. More generally, this study demonstrates that these lianas can escape the consequences of high density and thus the self-thinning law that affects self-supporting plants. This suggests a broader hypothesis about lianas in general: their greater flexibility in allocating growth resources allows them to grow taller and thinner without collapsing and thereby potentially escape shading and mortality even at high densities.

Release from root competition promotes tree seedling survival and growth following transplantation into human-induced grasslands in Sri Lanka

The density of colonising tree seedlings is often very low in degraded human-induced tropical grasslands. To investigate the mechanisms that constrain seedling establishment in grasslands on former tea plantations in Sri Lanka we planted seedlings of the native tree species Dimocarpus longan Lour., Macaranga indica Wight, Symplocos cochinchinensis (Lour.) S. Moore and Syzygium spathulatum Thw. and examined effects of vertebrate herbivory, and above- and below-ground competition exerted by the grass sward on seedling growth and survival over 28 months. Seedlings of the same species were also planted in remnant patches of lower montane rain forest to determine the effects of habitat on seedling growth and survival. Less than 40% of seedlings survived to 28 months post-transplantation. The highest survival was recorded for Symplocos cochinchinensis in both grassland and forest, while Macaranga indica seedlings had the highest relative growth rate of height (RGRh) in both habitats. Root competition reduced survival of Macaranga indica and the RGR h of Macaranga indica, Symplocos cochinchinensis and Syzygium spathulatum in the grassland, while above-ground competition and exclusion of vertebrate herbivores had no effects on seedling establishment. These results suggest that Symplocos cochinchinensis would be suitable for re-establishing forest cover on degraded grasslands, although Macaranga indica would be more likely to catalyse succession because it possesses animal-dispersed fruit. Measures that overcome or restrict the effects of root competition from grasses would enhance tree seedling growth and survival more than manipulation of the light environment or protection from vertebrate herbivores.

Early seedling establishment of two tropical montane cloud forest tree species: The role of native and exotic grasses

Tropical montane cloud forest has been undergoing a drastic reduction because of its widespread conversion to pastures. Once these forests have been cleared exotic grasses are deliberately introduced for forage production. Exotic grass species commonly form monodominant stands and produce more biomass than native grass species, resulting in the inhibition of secondary succession and tree regeneration. The purpose of this study was to assess the effect of native vs. exotic grass species on the early establishment of two native tree seedlings (Mexican alder, Alnus acuminata and Jalapa oak, Quercus xalapensis) on an abandoned farm in central Veracruz, Mexico. Seedling survival and growth were monitored (over 46 weeks) in relation to grass cover and height, and available photosynthetic active radiation (PAR). More seedlings survived in the presence of the native grass Panicum glutinosum than those growing with the exotic grass Cynodon plectostachyus (92% vs. 48%). The causes of seedling mortality varied between species; Q. xalapensis was affected by herbivory by voles but mainly in the exotic grass-dominated stands, whereas A. acuminata seedlings died due to competition with the exotic grass. A. acuminata seedlings increased more in height in the exotic grass-dominated stands (102 ± 7.8 cm) compared to native grass-dominated stands (51 ± 4.7 cm). Grass layer height, cover and available PAR were correlated (Pearson; p < 0.05). In the exotic grass dominated plots, grass layer height was correlated with the relative height growth rates of Q. xalapensis (Pearson; p < 0.05). These results indicate that the exotic grass may be affecting tree regeneration directly (grass competition) and indirectly (higher herbivory). Passive restoration may occur once P. glutinosum dominated pastures are abandoned. However, when C. plectostachyus dominates, introduction of early and mid successional tree seedlings protected against vole damage is needed.

Effects of the Physical Environment and Primate Gut Passage on the Early Establishment of Ampelocera hottlei Standley in Rain Forest Fragments

The regeneration of many tropical trees is threatened by forest fragmentation because it produces major physical, biological and ecological changes that limit seed germination and seedling establishment. We analyzed the regenerative potential of an old growth forest tree species—Ampelocera hottlei (Ulmaceae)—in three contrasting habitats located in the Lacandona rain forest, southeastern Mexico: continuous forest, fragments occupied by black howler monkeys (Alouatta pigra) and fragments unoccupied by howlers. We tested if germination of A. hottlei seeds among habitats was affected by understory temperature, light incidence and ingestion by A. pigra. We compared seedling survival and relative growth rate in height (RGRH) for 20 d among habitats and between ingested and control seeds (from mature fruits). Germination was higher in continuous forest than in fragments (occupied or not), with higher germination rates for ingested seeds in fragments. Temperature and light incidence were lower in continuous forest than in fragments. Germination decreased with increasing temperature and light incidence with this relationship being significantly higher for ingested seeds. Seedling survival was higher in continuous forest than in fragments, whereas RGRH did not differ among habitats. In addition, survival and RGRH were higher in seedlings originating from ingested seeds. Overall, our results suggest that the populations of A. hottlei can be limited in fragments where changes in the understory physical environment and the extirpation of A. pigra will likely have deleterious consequences for the regeneration of A. hottlei and possibly for other tree species, ultimately affecting forest composition and structure. Abstract in Spanish is available at http://www.blackwell-synergy.com/loi/btp.

The effect of bovine saliva on growth attributes and forage quality of two contrasting cool season perennial grasses grown in three soils of different fertility

The aim of this study was to determine the response of Dactylis glomerata L. (Orchardgrass) and Festuca ovina L. (Sheep fescue), to bovine saliva application in a loamy soil (most fertile), a sandy loam and a sandy soil (least fertile). The effects of cutting and cutting + saliva on relative height growth rate (RHGR), above- and belowground biomass and forage quality attributes [crude protein, NDF (neutral detergent fibre) and ADF (acid detergent fibre)] were investigated. The results showed that the cutting and cutting + saliva treatments resulted in greater RHGR than the control, but only with D. glomerata in the sandy soil did the application of saliva increase the RHGR. However, saliva applied after cutting increased the aboveground biomass averaged over all species and all three soils. Saliva applied to D. glomerata increased the belowground biomass in the sandy loam and sandy soils but decreased it in F. ovina in the sandy soil. The application of saliva had no effect on the crude protein or the NDF content of either species in any of the soils. On the other hand, the application of saliva after clipping increased the ADF of F. ovina but decreased that of D. glomerata averaged over all three soils. Averaged over both species, the ADF was increased by the addition of saliva in the sandy soil, had no significant effect in the sandy loam (P &gt; 0.05) and was slightly increased in the loam.

Close relationship between leaf life span and seedling relative growth rate in temperate hardwood species

AbstractThe life span of resource‐acquiring organs (leaves, shoots, fine roots) is closely associated with species successional position and environmental resource availability. We examined to what extent leaf life span is related to inter‐ and intraspecific variation in seedling relative growth rate (RGR). We examined relationships between relative growth rate in mass (RGRM) or height (RGRH) and leaf life span, together with classical RGRM components [net assimilation rate (NAR), specific leaf area (SLA), leaf weight ratio (LWR), and leaf area ratio (LAR)] for seedlings of five hardwood species of different successional position across a wide range of environmental resource availability, including the presence or absence of leaf litter in shaded forest understory, small canopy gaps, and large canopy gaps. Both SLA and LAR were negatively correlated with RGRM along the environmental gradient for all species. However, positive correlations were observed among species within microsites, indicating that these two components cannot consistently explain the variation in RGRM. Both NAR and LWR affect interspecific, but not intraspecific, variation in RGRM. Leaf life span was negatively correlated with either RGRM or RGRH in both inter‐ and intraspecific comparisons. Species with short‐lived, physiologically active leaves have high growth rates, particularly in resource‐rich environments. Consequently, leaf life span is a good predictor of seedling RGR. Leaf life span affects plant performance and has a strong and consistent effect on tree seedling growth, even among contrasting environments.

Drought Tolerance Of &lt;i&gt;Garcinia kola&lt;/i&gt; And &lt;i&gt;Garcinia afzelii&lt;/i&gt; At The Seedlings Stage

Garcinia kola and Garcinia afzelii are very useful forest tree species for chew stick and medicinal purposes in West Africa. They are currently receiving attention for cultivation due to the dwindling stocks of the species in the natural forest. Soil moisture is one of the most critical environmental factors that affect seedling growth in the field. The study was therefore conducted to test the response of the two species to variability in water availability. The seedlings were subjected to simulated no drought, 15-day drought, 30-day drought and 84-day drought. Seedling response to watering after 60-day simulated drought by withholding of watering was also monitored. Relative growth rate (RGR) in diameter decreased with the prolongation of the simulated drought period, and the difference was significant among all the treatments. For G. afzelii , simulated 84-day drought exhibited negative RGR in diameter, whereas for G. kola both the simulated 30-day and 84-day drought exhibited negative RGR in diameter. The RGR in height and leaf production was similar for the simulated no drought and the 15-day drought but significantly different from the 30-day and the 84-day drought period for G. afzelii. However for G. kola , it was the 15-day and 30-day simulated drought that were similar. Leaf production was highly correlated with height growth than with diameter growth. Release of drought-stress by the resumption of watering triggered leaf shedding up to a minimum value and thereafter increased. The relative rate of leaf production after re-watering increased, however the rate declined with the passage of time for G. afzelii but continued to increase for G. kola. Diameter growth was more affected than height by the dry conditions. The growth performance of G. afzelii was generally better than that of G. kola and both species have mechanisms for overcoming dry periods without experiencing mortality. Garcinia afzelii can be established in any of the forest zones, whereas Garcinia kola should preferably be established in Wet/Moist Forest and moist semi deciduous forest zones. Keywords : Garcinia species, simulated drought, diameter growth, height growth, leaf production

Effects of sediment burial disturbance on seedling survival and growth of Suaeda salsa in the tidal wetland of the Yellow River estuary

A greenhouse experiment was conducted to determine the effects of sediment burial on survival, growth and dry mass allocation of seedlings of Suaeda salsa (L.) Pall. (Chenopodiaceae), an important pioneer species of tidal wetland near the Yellow River estuary. From April to June 2009, seeds were buried at 0.5 cm depth in plastic pots filled with sediment. Two weeks after emergence, seedlings were buried to depths of 0 (H0), 33% (H33), 67% (H67), 100% (H100) and 133% (H133) of their mean height. Results showed that seedling survivorship, height, absolute height growth rate, relative height growth rate, stem diameter, number and length of branches, dry mass and relative growth rate were significantly affected by burial depth (P 0.05). No seedlings died in the partial burial treatment, approximately 18.06 ± 5.32% seedlings survived when they were completely buried, and no seedling survived when the burial depth reached 133% of the seedling height. Seedling height, absolute height growth rate, relative height growth rate, stem diameter, number and length of branch, dry mass and relative growth rate in the partial burial treatments were much higher than those of the unburied and completely buried treatments. With increasing burial depth, there was a tendency that both allocation to root and allocation to leaf increased, while allocation to stem decreased. The stem of S. salsa formed adventitious roots after being buried for less than 4 weeks, which was favorable for the survival and growth of seedlings, reflecting the fact that the S. salsa seedlings indeed exhibit a special adaptive strategy against rapid sediment burial in tidal wetland. The burial experiment also indicated that moderate burial disturbance (H33 and H67) increased seedling vigor, while strong burial disturbance (H100) reduced seedling vigor. The use of thin-layer sediment burial to promote the vigor of plants in degraded wetland is very feasible, and our results provide valuable practical information applicable to the restoration of degraded S. salsa wetland.

Mapping genome-wide QTL of ratio traits with Bayesian shrinkage analysis for its component traits

The ratio trait is defined as a ratio of two regular quantitative traits with normal distribution, which is distinguished from regular quantitative traits in the genetic analysis because it does not follow the normal distribution. On the basis of maximum likelihood method that uses a special linear combination of the two component traits, we develop a Bayesian mapping strategy for ratio traits, which firstly analyzes the two component traits by Bayesian shrinkage method, and then generates a new posterior sample of genetic effects for a ratio trait from ones of population means and genetic effects for the two component traits, finally, infers QTL for the ratio trait via post MCMC analysis for the new posterior sample. A simulation study demonstrates that the new method has higher detecting power of the QTL than maximum likelihood method. An application is illustrated to map genome-wide QTL for relative growth rate of height on soybean.

Crescimento inicial de espécies florestais na recomposição da mata ciliar em taludes submetidos à técnica da bioengenharia de solos.

A Bacia Hidrográfica do rio São Francisco, vem sendo submetida a fortes impactos ambientais por meio de alterações do regime hidrológico e sedimentológico, além de avançada destruição da sua mata ciliar. A vegetação ciliar possui importante função na proteção das margens dos rios promovida pela cobertura vegetal e seu sistema radicular, melhorando a agregação de um solo pouco coeso, diminuindo o arraste de partículas e, consequentemente resultando em menor taxa de erosão e assoreamento do curso d'água. Este trabalho teve como objetivo avaliar o crescimento inicial de espécies florestais em talude marginal submetido à técnica de bioengenharia de solos no rio São Francisco. A bioengenharia de solos foi composta pela cobertura longitudinal do talude com o biotêxtil (Tela Fibrax® 400BF), e em razão das variações diárias de cota do rio foram também utilizados retentores de sedimentos (Bemalonga® D40) para redução ao impacto da água na base do talude, evitando o solapamento promovido pelo fluxo e refluxo das ondas. Antes da fixação do biotêxtil, foram semeadas a lanço sementes da espécie Brachiaria decumbens para promoção de uma rápida cobertura vegetal. Em seguida foram plantadas mudas de seis espécies florestais nativas da região: aroeira vermelha (Schinus terebinthifolius Raddi.), pau-pombo (Tapirira guianensis Aubl.), mulungu (Erythrina velutina Willd.), tamboril (Enterolobium contortisiliquum (Vellozo) Morong), canafístula (Cassia grandis L.f.) e pau-ferro (Caesalpinia leiostachya (Bentham) Ducke). O desenvolvimento das mudas foi analisado por meio da Taxa de Crescimento Relativo de Altura da parte aérea e Diâmetro do colo. Após 360 dias, ao final das avaliações, observou-se que o maior número de indivíduos vivos foi identificado no tratamento com bioengenharia de solos. A grande densidade e agressivo crescimento da espécie Brachiaria decumbens na área com biotêxtil, trouxe danos para o desenvolvimento inicial das mudas arbóreas.

Effects of Light Intensity on Orthosiphon stamineus Benth. Seedlings Treated with Different Organic Fertilizers

The main objective of this study was to investigate the effects of varying light intensities and different organic fertilizers on the growth performance of O. stamineus seedlings through measurement of Relative Height Growth Rate (RHGR) and biomass production. Randomized Complete Block Design (RCBD) was used. Orthosiphon stamineus was arranged accordingly into three blocks or replicates. The three blocks represented the percentage light intensity. Block 1 (30% of light), Block 2 (50% of light) and Block 3 (100% of light). Each Block had four treatments and 25 plants of O. stamineus. The treatments were chicken dung, cow dung, oil palm empty fruit bunch (EFB) and control. The four treatments were arranged randomly in each block. Growth parameters measured were plant height, biomass (aerial portion, root biomass and total biomass within sixth month's period. The 50% Relative Light Intensity (RLI) was better than 30 and 100% RLI. The chicken dung is better than oil palm EFB and cow dung. © 2010 Academic Journals Inc.

Transplant Season, Irrigation, and Planting Depth Effects on Landscape Establishment of Baldcypress and Sycamore

Tree transplanting practices influence plant survival, establishment, and subsequent landscape value. The inability to adequately quantify effects of transplanting practices threatens long-term sustainability of landscape trees. Planting depth [i.e., location of the root collar relative to soil grade (soil surface)], is of particular concern for tree growth, development, and landscape performance. The authors of this study investigated the effects of planting depth and transplant season on landscape establishment of baldcypress [Taxodium distichum (L.) Rich.] and effects of planting depth and irrigation practices on landscape establishment of sycamore (Platanus occidentalis L.). Baldcypress planted above grade had reduced relative growth rate in height and diameter compared to those planted at or below grade during the first growing season, regardless of transplant season. Sycamore trees planted below grade had increased mortality and decreased growth compared to trees planted at grade or above grade, regardless of irrigation treatment. Even though trees of both species were grown under similar conditions, baldcypress was much more tolerant to belowgrade planting than sycamore. We suggest that this is related to the native habitat of both species, where baldcypress is frequently exposed to hypoxic conditions while sycamore is more prevalent on well-drained soils. Thus, it may be important to consider the native habitat of a species when evaluating the effect of planting depth.