Plants In Plots Research Articles

Productivity and feed management strategies of sambar deer (Rusa unicolor) at the special purpose forest area (KHDTK) of Aek Nauli

The availability of feed plants is one of the most important components in improving the breeding ability of sambar deer in captivity. Planting program and productivity assessment of feed plants are necessary to ensure the availability of feed plants for deer, including deer management demonstration plot at Aek Nauli KHDTK. This study was aimed to observe the productivity and nutritional contents of sambar deer feed plants in Aek Nauli KHDTK. This study was performed at the deer feed plant plot. Sampling activities were conducted in the 1x1 m2 plot (for grass) and 2 x 2 m2 (for non-grass such as shrubs and herbs). The results showed that the productivity of 6 feed plants is about 51,56 kg day-1 (fresh weight) or 19,52 kg day-1 (dry weight); indicating that these plants meet the needs of 5 deer which are requiring 38.82 kg feed day-1. The average productivity of feed plants in the dominant dry days was about 33,342.75 kg ha-1 year-1 (fresh weight) or 14,977.17 kg ha-1 year-1 (dry weight). The productivity of feed plants in the dominant rainy days was about 60,687.33 kg ha-1 year-1 (fresh weight) or 20,287.92 kg ha-1 year-1 (dry weight). Nutritional contents of feed plants are water content (56.3-66.0%), protein (0.037-0.156%), ash content (5.891-7.199%), fat content (1.751-10.089%), and carbohydrate (21.597-33.932%). Required feed management strategies are regular weeding, block division, rotational harvesting system, fertilizing, watering (during the dry season), and providing additional feeds and supplements such as Pennisetum purpureum, Calliandra callothyrsus, Artocarpus heterophyllus, and Manihot utilissima.

Variability of Silvicultural Characteristics of Forest Shelterbelts in Krasnodar Krai

Modern shelterbelts of Krasnodar Krai do not fully protect arable land and often have different sanitary state. Under these conditions, the preservation of forest shelterbelts and their protective functions in the system of agroforestry and other complex continues to be relevant. The research was carried out in the main and auxiliary forest shelterbelts within the boundaries of the Ust-Labinsk district of Krasnodar Krai. The purpose of the research was to determine the ecological state of the forest shelterbelts by identifying their integrity and implementation of forestry and land reclamation assessment. In order to obtain more complete information on their state, a remote assessment of the tree canopy integrity of the shelterbelts was carried out. It follows from the remote assessment analysis that about 42.5 % of the area surveyed in the key plots of plantations has an average degree of integrity of tree canopy, high – 22.3 %, low and very low – 35.2 %. Lower indicators of the tree canopy integrity are observed in the auxiliary forest shelterbelts. The percentage participation of each group of forest shelterbelts allowed us to rank the ranges of integrity corresponding to a certain forestry and land reclamation assessment (units). The range of the tree canopy integrity from 0 to 25 % corresponds to grade 1, from 25 to 50 % – 2, from 50 to 70 % – 3, from 70 to 100 % – 4. Based on this, the shelterbelts were devided into 4 groups: norm, risk, crisis and disaster. The results of determining the ecological state of the forest shelterbelts by ground and remote methods in the Ust-Labinsk district of Krasnodar Krai showed that a significant part of the surveyed plantations has a dense structure and requires silvicultural care. The group of the forest shelterbelts “disaster” needs reconstruction. This will significantly improve the environmental condition and reclamation efficiency, as well as increase the service life of the systems of forest sheltebelts.

The influence of cropping pattern of pepper with citronella and lemongrass to the insect diversity and insect pests population

Lemongrass and Citronella contain essential oils which are repellent against insect pests. Research on the cropping pattern of pepper with lemongrass and citronella was conducted to determine the influence of two essential oil plants on the diversity and population of insect pests of pepper plants. The research was conducted at the Sukamulya Experimental Garden, from 2018 to 2020 on a 3000 m2 planting plot. The treatments of the cropping patterns tested included: 1) Climbing pepper, 2) Climbing pepper + Shrub pepper, 3) Climbing pepper + Citronella, 4) Climbing pepper + Lemongrass, 5) Climbing pepper + Shrub pepper + Citronella, 6) Climbing pepper + Shrub pepper + Lemongrass. Each treatment was repeated twice. Observation parameters were insect diversity and insect pests, the level of pest attack, and the number of plants attacked. The results obtained about 66 species of insects from 46 families and 9 orders. The insects associated with the pepper cropping pattern ecosystem were relatively evenly distributed in all treatments, except for treatment 3, where only 4 types of insect pests were found. Pests, especially Thrips sp., were distributed in all treatments, but in the combination treatment with citronella and lemongrass, the population of Thrips sp. relatively low.

Distribution, Growth and Yield of <i>Santalum album</i> L. in Karnataka, India

Santalum album L. is distributed from Indonesia in the West to Juan Fernandez Islands in the East and from Hawaiian Archipelago in the North to New Zealand in the South. Sandalwood is one of the most important economic tree species harvested mainly for its heartwood and oil and is used in India from the earliest historic times. The sandalwood stands are under immense pressure and their management is becoming increasingly complex. Unfortunately, efforts aimed at conserving the genetic resources of sandalwood suffer from want of precise information on the area coverage, present status, growth characteristics and diameter size class distribution. In Karnataka, S. album is mainly found in Shimoga, Chickamagalur, Coorg, Hassan, Mysore, Dharwad, Bangalore, Kolar, Belguam, Uttar Kannada, Dakshin Kannada, Bellary and Tumkur districts. Keeping this in view, 41 sample plots were layed-out in sandal wood estates under Karnataka Forest Department. Out of 41 plots, 19 plots were laid out in sandalwood plantations (plantation plots), 4 plots were laid in regeneration plot and 18 plots are natural plots. The younger age plantations (3 - 6 years) are seen in Kadur, Bidar, Bangarpete, Srinivaspur, Malur, Mysore, Dharwad, Yelawala, and Kaggalipura ranges. Older plantation (15 - 20 years) are seen in Ambligola, Shkaripura, Shiralkoppa, Bangalore, Dundsi, Dharwad and JB kaval range. Significant variation in height and diameter growth was observed in all the sampled plots. Growth in Bangalore forest range was superior with 10.39 m of height and 11.52 cm of dbh compared to other ranges having natural distribution. Among the older trees grown under natural conditions, trees in Kadur range showed better height of 7.8 m and diameter of 8.31 cm.

A Brief Discussion on the Architectural Design of Commercial Complex Building -- An Example of the Design of the Comprehensive Office Building of Nantong Electric and Acoustic General Plant Plot

A Brief Discussion on the Architectural Design of Commercial Complex Building -- An Example of the Design of the Comprehensive Office Building of Nantong Electric and Acoustic General Plant Plot

Invasive plant Reynoutria japonica produces large amounts of phenolic compounds and reduces the biomass but not activity of soil microbial communities

Reynoutria japonica is one of the most invasive plant species. Its success in new habitats may be associated with the release of secondary metabolites. The aim of this study was to compare phenolic concentrations in plant biomass and soils between plots with R. japonica and resident plants (control), and determine the effects of these compounds on soil microbial communities. Samples of plant shoots and rhizomes/roots, and soil were collected from 25 paired plots in fallow and riparian habitats in Poland. We measured concentrations of total phenolics, condensed tannins, catechin, chlorogenic acid, emodin, epicatechin, hyperoside, physcion, piceatannol, polydatin, procyanidin B3, quercetin, resveratrol, and resveratroloside. Soil microbial parameters were represented by acid and alkaline phosphomonoesterases, β-glucosidase, phenoloxidase, and peroxidase activity, culturable bacteria activity and functional diversity measured with Biolog Ecoplates, and microbial biomass and community structure measured with phospholipid fatty acid (PLFA) analysis. We found that concentrations of total phenolics and condensed tannins were very high in R. japonica leaves and rhizomes/roots, and concentrations of most phenolic compounds were very high in R. japonica rhizomes/roots when compared to resident plant species. Concentrations of most phenolics in mineral soil did not differ between R. japonica and control plots; the only exceptions were catechin and resveratrol which were higher and lower, respectively, under the invader. Total microbial and bacterial (G+, G–) biomass was decreased by approx. 30% and fungal biomass by approx. 25% in invaded soils in comparison to control. Among soil functional microbial parameters, only peroxidase activity and functional diversity differed between R. japonica and resident plant plots; peroxidase activity was higher, while functional diversity was lower in soil under R. japonica. The negative effects of R. japonica on microbial biomass may be related to catechin or its polymers (proanthocyanidins) or to other phenolics contained in high concentrations in R. japonica rhizomes.

Integrated Weed Management Systems to Control Common Ragweed (Ambrosia artemisiifolia L.) in Soybean

As resistance to herbicides limits growers' weed management options, integrated weed management (IWM) systems that combine non-chemical tactics with herbicides are becoming critical. A 2 year integrated weed management (IWM) study was conducted at three locations in VA, USA. The factorial study evaluated: (1) soybean planting date (early or late planted) (2) with or without winter cover (cereal rye/wheat or no cover), and (3) with or without harvest weed seed control (HWSC). Prior to soybean planting in the first year, winter cover resulted in a 22% reduction in common ragweed density compared to no cover. At soybean harvest in the first year, the lowest common ragweed densities were in the late planted plots following winter wheat, and common ragweed aboveground biomass was reduced by 46 and 22% at two locations in late planted compared to early planted soybean. To evaluate the impact of the first year's treatments and HWSC, full season soybeans were planted across the trial in the second year. Prior to soybean planting in the second year, late planting in the first year common ragweed density was reduced by 83% at one location, but significant reductions were not observed elsewhere. When comparing winter cover to no cover, common ragweed densities were reduced by 31 and 49% at two locations and densities were similar at the third location. Harvest weed seed control reduced common ragweed density by 43% at one location compared to the conventional harvest plots but no significant reductions were observed at the other locations or at other rating timings. However, there was a significant location by planting date by winter cover interaction and the overall lowest common ragweed densities (4.1 to 10.3 plants m−2) were in the late planted plots with winter cover. This research indicated that winter cover, late planting, and HWSC can reduce common ragweed populations with late planting being the most influential. Therefore, double-cropping soybean after wheat is likely the most viable means to better control common ragweed using IWM as it combines both winter cover and late planting date.

Vegetative spread is key to applied nucleation success in non‐native‐dominated grasslands

Applied nucleation (i.e. planting vegetation patches) is a restoration strategy that better recreates natural ecosystem heterogeneity and requires fewer resources compared to planting the entire area. Whereas applied nucleation shows promise as a forest restoration strategy, this approach has received little study in grassland restoration, where the spread of planted vegetation nuclei may be impeded by aggressive non‐native species. We compared the establishment and cover of restored native grass, forb, and rush species for 7 years in applied nucleation and full planting treatments in a former agricultural site dominated by non‐natives along the central California coast. We planted seedlings of the same nine coastal prairie species in all treatments, but the applied nucleation plots had four nuclei with only 30% of the seedlings as the full planting plots. We also evaluated the effect of adding wood mulch to reduce non‐native plant competition. Native forb cover increased over time and was similar across treatments in the final study year. Native grasses increased for the first 4 years and then declined sharply in all treatments. Native forb cover spread into unplanted areas in applied nucleation plots, whereas grasses showed minimal spread. Of the five planted forb species, the two that persisted until the final study year both spread via rhizomes. Wood mulch reduced non‐native cover in the first 2 years and had a longer‐term effect on species composition. Our results suggest that applied nucleation can be an effective restoration strategy at a small scale in non‐native‐dominated grasslands for species that spread vegetatively.

Tillage Impacts on Initial Soil Erosion in Wheat and Sainfoin Fields under Simulated Extreme Rainfall Treatments

The main aim of this research was to determine the potential effects of different tillage systems (TT: traditional tillage and RT: reduced tillage) on runoff and erosion at two different locations (Kahramanmaras and Tarsus, Southern Turkey) under (i) fallow, (ii) wheat (Triticumaestivum L.), and (iii) sainfoin (Onobrychissativa L.) crops. Rainfall simulations with intensity of 120 mm h−1 and 30-min duration, representing a typical extreme thunderstorm in this area, were used. We quantified the elapsed time to runoff generation (ET), total runoff volume (R), soil loss (SL), sediment concentration (SC), and runoff coefficient (RC). At both locations, the fallow plots indicated the first runoff response ranging between 1.2 and 3.1 min, while the range was between 9.4 and 8.9 min for the sainfoin plots. The highest runoff coefficient was recorded for the fallow parcel in Tarsus (57.7%), and the lowest runoff coefficient was recorded for the sainfoin parcel in Kahramanmaras (4%). For both study sites, the fallow plots showed higher soil erosion rates (871 and 29.21 g m−2) compared with the wheat plots (307 and 11.25 g m−2), while sainfoin recorded the lowest soil losses (93.68 and 3.45 g m−2), for Tarsus and Kahramanmaras, respectively. Runoff and sediment yield generated from sainfoin and wheat parcels under the RT system were less than under the TT system at the Kahramanmaras location. At the Tarsus location, the effect of soil tillage on soil and water losses was insignificant on the sainfoin planted plots. The reduced tillage system was successful in reducing sediment yield and runoff generated from parcels growing wheat and sainfoin compared to traditional tillage in Tarsus location, but runoff and soil loss were found to be very high compared to parcels constructed in the Kahramanmaras location.

Assessing the reforestation effects of plantation plots in the Thai savanna based on 45 cm resolution true-color images and machine learning

In forest restoration projects, assessing progress is critically important. This study was conducted to quantify the restoration progress for approximately 30 year old plantation plots of Acacia and Pterocarpus in Sakaerat, Thailand. For 22.5 × 22.5 m areas in the plantation plots, as a continuous measure of forest restoration, dry evergreen forest-likelihood was determined using 45 cm resolution satellite images and an artificial neural network architecture. The Acacia plot achieved a moderate mean evergreen forest likelihood of 0.451 (April 2016) to 0.679 (May 2019), but the values for the Pterocarpus plot were 0.076 or smaller. Two other Pterocarpus plots at cooler and moister sites had mean evergreen forest-likelihood values of up to 0.884 (April 2016), which were significantly greater than that (0.451) for the Acacia plot, but the values dropped in May 2019. Throughout the period of the four image acquisition times from March 2014 to May 2019, the plantation plots had significantly smaller evergreen forest-likelihood than the dry evergreen forest did. The current approach would be a helpful option for stakeholders of forest management by applying sub-m-resolution images and machine learning followed by quantification of the forest restoration effects relying on the appearance and texture of tree canopies at multiple data acquisition times.

Diversity of beetles (Coleoptera) in natural and planted saxaul forests (Haloxylon ammodendron) in the South Gobi Desert, Mongolia.

We investigated species composition and diversity parameters of beetle communities in two planted saxaul (Haloxylon ammodendron, black saxaul) forests in Southern Mongolia. We also studied nearby natural areas for comparison. Beetles were mainly collected by pitfall traps. 1064 individuals of 38 species of 22 genera in 4 beetle families were identified from planted plots. In comparison, a total of 1395 beetles belonging to 40 species of 24 genera in seven families were collected and identified from the natural saxaul plots. The most diverse beetle families were darkling beetles (Tenebrionidae, 18 species) and snout beetles (Curculionidae, 15 species) in planted and natural saxaul plots. We recorded several species (Apatophysis serricornis, Cephogenia chinensis, and Eumylada punctifera punctifera) which are associated with the saxaul tree. A darkling beetle, Anatolica potanini, was the dominant species in both natural and planted plots of the Nariin Zag forest. There were significant differences in the species richness and abundance between the planted and natural plots of the Ukhaa Zag forest. It is possible that the age of the plantation drove the differences. The higher values of diversity indices and species richness in the planted plots can be explained by the presence of rare species, represented by only one or two individuals. The planted plots and corresponding natural plots within each forest were more similar to each other in species composition and abundance than between forests.

Effect of Plant Pattern and Density on Yield and Amino Acid Profile of Tepary Bean (Phaseolus acutifolius) in a Semiarid Area

Background: Tepary bean is recognized as a deal crop for cultivation in arid and semi-arid regions. The spatial distribution of plants is an important farming practice. A study was conducted in tepary bean (Phaseolus acutifolius A. Gray) to investigate the effect of planting pattern and plant density on plant yield and amino acid profile.Methods: The experiment was carried out in a split-split plot design with three replications during 2017 and 2018. The main plot comprised planting pattern at two levels, including one-row plantation (PP1) and two-row plantation (PP2) and sub plot comprised plant density at three levels, including high plant density (HPD:50 plant/m2), moderate plant density (MPD:40 plant/m2) and low plant density (LPD: 30 plant/m2). In both years, plants were harvested at the end of pod filling stage at October. Amino acid profiles were determined using a HPLC system. Result: The results showed that in the first year and under PP2, MPD increased the biological yield by 19% and 16% compared to HPD and LPD, respectively. Increased pod yield was observed at MPD compared to HPD and LPD. In the second year under PP1, MPD improved grain yield by 75% and 65% in comparison to HPD and LPD, respectively. Increased protein and amino acid content were observed at MPD and PP2. The greatest amino acid content was Leu followed by Lys, Arg, Phe, Val, Ile, Thr, Tyr, His, Met, Trp and Cys.

Biomass Yield Evaluation for Switchgrass Breeding: Seeded Swards vs. Transplanted Plots Yield Different Results

Switchgrass (Panicum virgatum L.) is undergoing intensive development as a biomass crop to support the production of energy from perennial grasslands. Plant breeding and selection represent a significant component of this development effort, requiring breeders to evaluate large numbers of genotypes and families for performance under real-world field conditions. Experimental unit size, shape, and interplant spacing can vary widely both within and across breeding programs, and there is some evidence that experimental units established from seedling transplants are poorly predictive of biomass yield in seeded swards. The purpose of this study was to determine the relationships among five types of experimental units, three based on transplanted seedlings (spaced plants, row plots, and simulated sward plots) and two based on seeded rows (bordered and unbordered sward plots). Nine switchgrass populations were evaluated with or without nitrogen fertilizer under all five plot types. Simulated sward plots had the lowest predictive value for biomass yield of sward plots. Spaced plants and row plots had greater predictive ability than simulated swards, but they accounted for less than 50% of the variability, suggesting that biomass measurements on these types of plots should not be considered as the same trait measured on seeded sward plots, especially considering the fact that the conditions of interplant competition are drastically different between these groups of plot types. Whereas biomass yield on a per-hectare basis would be an appropriate trait name for seeded swards, plot-specific terms such as “plant biomass” or “row biomass” are more appropriate for biomass measured on spaced plant plots or row plots. These terms would clearly indicate that measurements on seeded plots where there is intensive interplant competition are not the same trait as those made on plants without competition.

ADOPTION OF FARMERS IN THE IMPLEMENTATION OF TOMATO GOOD HANDLING PRACTICES (GHP) IN VILLAGE SENANING SUBDISTRICT

Tomato plants are vegetables that are easily damaged (parisable) so that requires the application of Good Handling Practices (GHP) which aims to reduce post-harvest yield loss. The purpose of this Final Assignment study is to increase farmers' knowledge about the application of tomato GHPs, namely treatment from harvest to market. This Final Project was carried out in the village of Senaning, Pemayung Sub-District, Batanghari Regency, Jambi Province from March to July 2020. The method used was descriptive method and multiple linear regression. Respondents were taken as many as 30 people who were determined deliberately (purposive sampling), namely farmers who are members of the tomato farmer group. The results showed that of 30 respondents at the level of farmer adoption, there were 17 knowledge persons in the low category (56.7%) and 13 moderate people (43.3%). Factors that influence the adoption of farmers in the application of GHP tomatoes are divided into 7 namely age, education, experience of farming, the role of extension workers, extension activities, availability of information and availability of facilities and infrastructure. From the analysis of variance analysis (Anova), it was found that all seven independent variables had a significant effect on the adoption of GHP tomato farmers (0.000> 0.05). Partially using the multiple linear regression formula, the results found that 6 independent variables, namely age (0.003), education (0.017), experience of farming (0.001), role of extension workers (0.029), extension activities (0.008), and availability of information (0.048) influence significant towards the adoption of farmers in the application of tomato GHP (Sig <0.05). While the availability of production facilities does not affect the adoption of farmers in the application of tomato GHP (0.119). The strategy taken to increase the adoption of farmers in the application of tomato GHP is by conducting counseling of tomato GHP and making a demonstration plot of tomato plants. After counseling there was a significant increase in the knowledge of farmers on tomato GHP with the T test sig (0,000).

Growth and Yield Parameters of Introduced Oil Palm Crop in Uganda

Oil palm is commercially grown on Bugala Island within Lake Victoria. But with increasing demand for vegetable oils in Uganda more areas for oil palm production are required. A study was conducted to identify new areas suitable for oil palm production. The experiment was super-imposed on 45 × 45 m plots in 3-year old oil palm plantations in Bugiri, Buvuma, Kibaale and Masaka. The experiment was laid out in a randomized complete block design with three replications. From 2011 to 2013 results indicated significant (P < 0.05) mean increments from 98.9 to 141 cm in height, 166 to 377 cm in stem girth, 24.3 to 30.1 in number of open leaves and 40.3 to 81.2 in number of flowered palm trees. On the monthly basis the highest fresh fruit bunch (FFB) number and yield were realized in May and October, respectively which corresponded with the peak rain months. Furthermore, significant (P < 0.05) increments of 40.9% in number of FFB, 55.4% in bunch weight and 16.9% in yield were observed from 2014 to 2016. Across sites, Kibaale had the highest (601.5 FFB ha-1) number of FFB while Masaka registered the lowest number (452.2 FFB ha-1). Oil palm yield in Kibaale and Buvuma was twice higher than in Masaka. But, yield in Bugiri was not significantly different from that of Buvuma and Kibaale but significantly (P < 0.05) higher than in Masaka. The findings on growth and yield of introduced oil palm crop revealed that Kibale, Buvuma and Bugiri are potential areas for oil palm production in Uganda.

Are native and non-native pollinator friendly plants equally valuable for native wild bee communities?

Bees rely on floral pollen and nectar for food. Therefore, pollinator friendly plantings are often used to enrich habitats in bee conservation efforts. As part of these plantings, non‐native plants may provide valuable floral resources, but their effects on native bee communities have not been assessed in direct comparison with native pollinator friendly plantings. In this study, we performed a common garden experiment by seeding mixes of 20 native and 20 non‐native pollinator friendly plant species at separate neighboring plots at three sites in Maryland, USA, and recorded flower visitors for 2 years. A total of 3,744 bees (120 species) were collected. Bee abundance and species richness were either similar across plant types (midseason and for abundance also late season) or lower at native than at non‐native plots (early season and for richness also late season). The overall bee community composition differed significantly between native and non‐native plots, with 11 and 23 bee species being found exclusively at one plot type or the other, respectively. Additionally, some species were more abundant at native plant plots, while others were more abundant at non‐natives. Native plants hosted more specialized plant–bee visitation networks than non‐native plants. Three species out of the five most abundant bee species were more specialized when foraging on native plants than on non‐native plants. Overall, visitation networks were more specialized in the early season than in late seasons. Our findings suggest that non‐native plants can benefit native pollinators, but may alter foraging patterns, bee community assemblage, and bee–plant network structures.

Comparison of the interest of four types of organic mulches to reclaim degraded areas: a field study based on their relative attractiveness for soil macrofauna

The study focused on the attractiveness of mulches (consisting of the addition of a layer material to the soil surface) and their efficiency to promote recolonization by pedofauna of isolated and degraded areas. The experimental study was set up in the former coal mining area of Northern France. This area is particularly disturbed and fragmented by land-use change, urbanization, industry, intensive agriculture and metal pollution. To examine the movements of pedofauna, four kinds of mulches were applied: (i) Ramial Chipped Wood (RCW), (ii) chopped Miscanthus, (iii) dead leaves and (iv) wheat straw as well as plastic sheeting, a material often used in green spaces. A negative control consisted in soil without mulch addition. The experimental set-up consisted of a set of 18 bands of mulch (6 m long x 0.5 m width x 8 cm thick, i.e. a volume of 0.04 m3 per band) installed on three adjacent plots on a surface area which stretch on 4400 m2: (i) plot F1, a mixed plantation, (ii) plot M consisted of three rows of maples (both considered to be the reservoir of biodiversity) and (iii) plot BF, an ash plantation (with lower biodiversity). Faunistic communities of soil present within the mulches were monitoring using pitfall traps for four months (April to July), at a rate of eight surveys for each of the 90 traps installed, i.e. 720 samples. Different life traits and indices of diversity were studied, more specifically on carabid beetles. The main objective of the study was first to check whether mulches could or not reconnect different planted plots in a peri-urban landscape highly modified by human activities. The second aim was to find which type of mulch had the best efficiency in the recovery of the connectivity between plots. The last questions were which type of zoological groups could be favoured by the use of mulches and which benefits for ecosystem functioning. The main hypotheses of this study were: (i) Organic mulches would act as dispersal corridors and refuge zones to the soil organisms; (ii) organic mulches would be attractive to many organisms with various ecological needs.This study highlighted the potential benefits of using the mulching technique to support ecological connectivity in disturbed environment since this method highlighted the presence of individuals with different diets (saprophagous, predators, phytophagous and so forth), small and large size species which do not have the same dispersal capacities as well as species that are more dependent on forest environments and others that depend on more open environments. The study concluded that organic mulches are more favourable to pedofauna than soil without mulch or plastic sheeting. With regard to organic mulches, no difference was noted, either in terms of cumulative abundance or monthly monitoring. However, for carabids, it should be noted that dead leaves and wheat straw have higher specific richness than Miscanthus and RCW.

Prediction models of knot volume inside the stem for Korean pine plantation

Based on 1207 knots from 49 sample trees of 29 standard plots of Korean pine plantations in Linkou and Dongjingcheng Forest Bureau of Heilongjiang Province, China, we extracted longitudinal sections of knots using the image processing software Digimizer and represented the shape of knots using two-dimensional scatter plots. According to the two-dimensional scatter plots, knots of Korean pine plantation were divided into three types: 1) alive knots (whole knot contained only sound knot portion); 2) non-occluded dead knots (whole knot contained both sound and loose knot portions); 3) occluded dead knots (the sound and loose portion of the knot were partially occluded by the bark). For all the three types of knots, the volume of sound knot was calculated by mathematical integral of the sound knot shape equation. The volume of loose knot was calculated using the volume equation of a cylinder. The total volume of knots was calculated as the sum of sound and loose knot volume. Finally, based on knot variables (diameter, relative height and total length of knots) and tree variable (diameter at breast height), we established the prediction models for sound knot volume, loose knot volume, and total volume of knot using the linear mixed model at plot level and tree level. Compared with fixed-effects model, the mixed effects models of the volume of sound knot, loose knot, and total knots provided more accurate parameter estimation, more uniform residual distribution, and higher model fitting precision. The validation results showed that prediction precision of each fixed-effect model was higher than 90%, while that of the mixed models with plot and tree effect was above 93%, indicating that the established model could well predict the volume of knot for Korean pine plantation.

Effect of Napier grass shoots characteristics on runoff and sediment outflow under concentrated overland flow conditions

Vegetation cover is very effective measure to control environmental conditions. In this study, the potential of Napier grass to reduce soil erosion was evaluated. Parameters include number of stems, shoot length, number of leaves, leaf area index and experiments were performed using a hydraulic tilting flume and controlled water circulation system. Extensive experiments were carried out using (i) control (ii) whole plant plot and (iii) roots plot at 2% slope with 10.7 l/s/m discharge rate. Results summarized that Napier grass produced significantly lesser soil erosion and runoff as compared to the control. Further, it was observed that the sediment outflow and runoff generation significantly decreased with the growth stage of Napier grass. Roots were found more effective in controlling sediment rates, while shoots were more effective in reducing runoff rate. The correlation analysis indicated that runoff and sediment outflow was highly negatively correlated with the leaf area index and the number of stems, respectively.

Eight-year ecophysiology and growth dynamics of Picea rubens seedlings planted in harvest gaps of partially cut stands

In order to compensate for regeneration failure of red spruce (Picea rubens) in the managed temperate mixedwood forest, an enrichment planting study was conducted in yellow birch (Betula alleghaniensis)–conifer stands, in Quebec, Canada. The experimental design compared four cutting treatments: an uncut control (26 m2·ha−1 of merchantable basal area [BA], with mean natural canopy gap areas of ≤ 100 m2 each) and three hybrid single-tree and group-selection cuttings corresponding to a light cut (20% removal; residual BA [RBA]: 21 m2·ha−1; mean harvest gap area: 220 m2), a moderate cut (31% removal; RBA: 18 m2·ha−1; gap area: 270 m2), and a heavy cut (42% removal; RBA: 15 m2·ha−1; gap area: 340 m2). In the cuts, large-sized containerized seedlings of red spruce were planted within harvest gaps, while in the control, seedlings were planted systematically, for comparison. Three years later, a mechanical release treatment was applied in half of planted plots to limit competing vegetation. After eight years, seedling survival in the three cuts was equally high (> 80%), and greater than in the control (40%). Morphophysiological performance of seedlings was best in the heavy cut creating the largest gaps. In general, the release treatment enhanced survival in the control and in the light cut with the smallest gap sizes. Release also improved morphophysiological performance (which, however, remained suboptimal) in all cutting treatments, but especially in the heavy cut. Although red spruce is highly shade-tolerant, the low survival and performance in the control suggest that for this species, seedlings grown with traditional forest nursery practices are not adapted to plantation under a closed canopy. Results indicate that enrichment planting in intermediate-size harvest gaps (of about 340 m2 in area) of partially cut stands (of about 40% in BA) combined to mechanical release could be a good strategy to maintain or reintroduce red spruce and promote its morphophysiological performance.