Tree Foliage Research Articles

Allometric Equations for Estimating Silk Oak (Grevillea robusta) Biomass in Agricultural Landscapes of Maragua Subcounty, Kenya

Grevillea robusta is widely interplanted with crops in Maragua subcounty, a practice that enhances biomass quantities in farmlands. However, quick tools for estimating biomass of such trees are lacking resulting in undervaluation of the farm product. This study sought to develop allometric equations for estimating tree biomass using diameter at breast height (DBH) and tree height as predictor variables. Tree biomass was computed using thirty-three (33) trees randomly selected from 12 one hectare plots established in each of the four agroecological zones (AEZs). DBH of all Grevillea robusta trees per plot was measured and three trees were selected for destructive sampling to cover the variety of tree sizes. Regression analysis was used to develop equations relating DBH/tree height to biomass based on linear, exponential, power, and polynomial functions. The polynomial and the power equations had the highest R2, lowest SEE, and MRE values, while DBH was the most suitable parameter for estimating tree biomass. The tree stem, branches, foliage, and roots biomass comprised 56.89%, 14.11%, 6.67%, and 22.32% of the total tree biomass, respectively. The mean tree biomass density (12.430±1.84 ton ha−1) showed no significant difference (p=0.09) across AEZs implying no difference in G. robusta agroforestry stocks across the AEZ. The allometric equations will support marketing of tree products by farmers and therefore better conservation and management of the tree resource.

Automatic Segmentation of Tree Structure From Point Cloud Data

Methods for capturing and modeling vegetation, such as trees or plants, typically distinguish between two components—branch skeleton and foliage. Current methods do not provide quantitatively accurate tree structure and foliage density needed for applications such as visualization, inspection, or to estimate vegetation parameters. This letter describes an automatic method for segmenting three-dimensional point cloud data of vegetation, acquired from commodity scanners, into its two main components: branches and leaves , by using geometric features computed directly on the point cloud. In this letter, the specific type of vegetation considered is broadleaf trees. We present a data-driven approach, where a Random forest classifier is used for segmentation. In contrast to state-of-the-art methods, the point cloud is not reduced to a set of primitives such as cylinders. Instead, the algorithm works at the level of the input point cloud itself, preserving quantitative accuracy in the resulting model. Computation of typical vegetation metrics follows naturally from this model. We achieve an average classification accuracy of $91\%$ on simulated data across three different species of broadleaf trees. Qualitative results on real data are also presented.

Effect of Winter Herbicide Applications on Bald Cypress (Taxodium distichum) and Giant Salvinia (Salvinia molesta)

AbstractImmense stands of bald cypress [Taxodium distichum (L.) Rich.] make it difficult for herbicide applicators to access the free-floating fern giant salvinia (Salvinia molesta Mitchell), which can be found growing under the canopy of the trees. The difficulty of accessing these areas, as well as avoiding direct contact of herbicides with tree foliage, provides a substantial amount of nonmanaged plant material capable of rapidly reinfesting treated sites, thus making management efforts null and void. Herbicide application during the winter, when bald cypress sheds its leaves, may be an ideal time to manage S. molesta and minimize negative impacts on the nontarget tree. Therefore, the herbicides diquat, glyphosate, flumioxazin, and glyphosate+diquat were evaluated at one of the three application timings (December, January, or February) against S. molesta and immature bald cypress during the winter. All herbicide treatments, except diquat applied in February of year 1, reduced S. molesta biomass 40% to 100%. In addition, flumioxazin applications during December, January, and February provided ≥70% S. molesta control with little or no negative impacts to bald cypress health. A treatment by timing interaction revealed that trees exposed to flumioxazin did not result in a significant decrease in average leaf length when compared with reference trees 20 wk after bud break at any of the three application timings. In addition, bald cypress exposed to flumioxazin produced the highest probability of a refoliation pattern equivalent to the nontreated reference trees. Although complete tree mortality was not documented in either study, delayed and abnormal leaf formation, reduced leaf length, irregular canopy formation, or no negative effects were observed among herbicide-treated bald cypress. This research suggests that winter herbicide applications over the top of dormant bald cypress may be a practical management technique for controlling severe infestations of S. molesta.

Bat Fauna (Mammalia: Chiroptera) of Southern Odisha Along the Eastern Ghats, India

Bats have not received adequate attention in biodiversity research and conservation activities in India despite their ecological values. In the present study, we carried out an inventory of bat fauna in southern Odisha region during September 2014 to August 2016 and recorded a total 16 species of bats in seven families, of which the insectivorous bats were represented by maximum 12 species over frugivores and carnivores. During the study 76 roosting sites were recorded from exposed branches, foliage and cavities of trees, caves, crevices in large rocks and abandoned buildings and caves were significantly preferred by maximum 11 species. Gupteswar cave tourism site in Koraput district was found to be the most diverse and important bat roosting and breeding site in southern Odisha region. Cave tourism, hunting for ethno-zoological practices and cutting down of roosting trees were observed as major threats to bats. As the inventory was primarily based on roost survey, more systematic survey using mist nets and acoustic monitoring can further strengthen the bat fauna database of southern Odisha.

Predation by avian insectivores on caterpillars is linked to leaf damage on oak (Quercus robur)

Birds that are foraging in tree canopies can cause a substantial decrease in arthropod numbers. Trees may benefit from avian insectivores attacking insect herbivores. In a field study, we tested whether the intensity of bird predation on caterpillars is linked quantitatively to leaf damage caused by insect herbivores, a hypothesized relationship that previously was poorly investigated. Artificial caterpillars were placed in the lower part of oak trees (Quercus robur) in urban and suburban sites across the city of Gothenburg, Sweden. Two days later, we recorded the survival: the pooled predation rate was 11.5% (5.7% day−1). Mean predation rate per tree was 10.4%. Mean leaf damage, i.e. leaf area eaten by insect herbivores, per tree was 5.7% but there was large variation between trees. We found a significant negative relationship between survival probability of caterpillars and leaf damage in an analysis using a mixed model logistic regression. This suggests that caterpillars are at high risk of bird attacks in trees with a high degree of leaf damage and avian insectivores may increase the foraging effort in the foliage of such oak trees. Our findings concerning the quantitative relationship between the predator–prey interactions and plant damage suggested tentatively that the survival probability of caterpillars decreases rapidly at 15–20% leaf damage in lower part of oak canopies. Furthermore, our findings add credence to the idea of using artificial caterpillars as a means to obtain standardized comparisons of predation rates in various habitats.

Saprotrophic and ectomycorrhizal fungal sporocarp stoichiometry (C : N : P) across temperate rainforests as evidence of shared nutrient constraints among symbionts.

Quantifying nutritional dynamics of free-living saprotrophs and symbiotic ectomycorrhizal fungi in the field is challenging, but the stoichiometry of fruiting bodies (sporocarps) may be an effective methodology for this purpose. Carbon (C), nitrogen (N) and phosphorus (P) concentrations of soils, foliage and 146 sporocarp collections were analyzed from 14 Pseudotsuga menziesii var. menziesii stands across a podzolization gradient on Vancouver Island (Canada). N and P concentrations were considerably higher in saprotrophic fungi. Fungal N% increased with soil N content at a greater rate for saprotrophs than ectomycorrhizal fungi, while fungal P% of saprotrophs was more constrained. Fungal N : P was more responsive to soil N : P for ectomycorrhizal fungi (homeostatic regulation coefficient 'H' = 2.9) than saprotrophs (H = 5.9), while N : P of ectomycorrhizal fungi and host tree foliage scaled almost identically. Results underscore the role of ectomycorrhizal fungi as nutrient conduits, supporting host trees, whereas saprotrophs maintain a greater degree of nutritional homeostasis. Site nutrient constraints were shared in equal measure between ectomycorrhizal fungi and host trees, particularly for P, suggesting neither partner benefits from enhanced nutrition at the expense of the other. Sporocarp stoichiometry provides new insights into mycorrhizal relationships and illustrates pervasive P deficiencies across temperate rainforests of the Pacific Northwest.

How stand tree motion impacts wind dynamics during windstorms

Understanding how wind and trees interact during wind storms is crucial for better predicting forest wind damage. The complexity of this interaction is enhanced by the fragmented environment of forests. Here, we present an unprecedented field experiment (TWIST) where both the wind dynamics and the tree motion in the edge region of a maritime pine forest have been recorded simultaneously during four non-destructive wind storms. For three of them, the instrumented trees were under stand flow while for one of them they were under an edge flow. Our measurements demonstrate that the well-known characteristics of stand-flow dynamics remain valid under high wind conditions. Only the sub-canopy flow appeared more intermittent as canopy-top turbulent structures penetrate easier within the canopy due to the tree foliage reconfiguration. Under similar storm intensity, the tree motions were lower under edge flow than under stand flow due to the lower turbulence of the former flow while the mean wind speed was higher. This result demonstrates the importance of considering both the turbulence and the mean wind speed in wind risk models. No impact of tree motion other than tree reconfiguration were observed on the stand flow dynamics. On the other hand, for the edge flow, our measurements reveal a peak in frequency on the wind velocity fluctuations related to the fundamental tree vibration mode. This peak was especially visible at canopy top and in the upper trunk space under high wind conditions. Compared to the stand flow, we suspect that the velocity fluctuations induced by the tree motion emerge in the edge flow due to the lower background turbulence. Our edge storm was nonetheless not strong enough for tree motion to enhance flow turbulence and for trees to enter into resonance. These findings may suggest a higher susceptibility of near-edge trees to reach resonance than stand trees due to the motion of upwind trees in a lower background turbulence.

Using a dune forest as a filtering ecosystem for water produced by a treatment plant – One decade of environmental assessment

A dune forest in SW France composed of maritime pines was irrigated with treated wastewater for a decade in an experiment (including irrigated plots versus control plots) to evaluate the environmental impact of applying wastewater on the water table, soil properties, and plants. The amount of treated wastewater (1921 mm yr−1) applied was twice the annual precipitation. Nutrient inputs were also very high, particularly nitrogen (N: 539 kg-N ha−1 yr−1), phosphorus (P: 102 kg-P ha−1 yr−1), and calcium (Ca: 577 kg-Ca ha−1 yr−1). Irrigation caused a rise in the water table, and increased its sodium (Na), NO3−, potassium (K), and calcium concentrations. Soil properties were affected by irrigation at least down to a depth of 1.2 m. After eight years of irrigation, soil pH had increased by 1.4 units, and soil available P content (POlsen) increased nearly 8-fold. In the short-term (i.e. 1–3 years), irrigation with treated wastewater improved growth, standing biomass, and the nutritional status of the vegetation. But tree dieback started in the fourth year of irrigation and worsened until the end of the monitoring period when almost all the irrigated trees were dead or moribund. The understory composition was drastically modified by irrigation, with an increase in α-biodiversity and in the biomass of herbaceous species, and a reduction in woody species abundance. The factor that best explained tree dieback was manganese nutrition (Mn): (i) the Mn content of the tree foliage was negatively affected by irrigation and below the deficiency values reported for pine species, and (ii) soil available Mn (CaCl2 extraction) decreased by half in the topsoil layer. Manganese deficiency was probably the consequence of the increase in soil pH, which in turn reduced soil Mn availability. Tree dieback was not related to either to a macronutrient deficiency or to toxicity caused by a trace element.

Bacterial endophyte communities in Pinus flexilis are structured by host age, tissue type, and environmental factors

Forest tree microbiomes are important to forest dynamics, diversity, and ecosystem processes. Mature limber pines (Pinus flexilis) host a core microbiome of acetic acid bacteria in their foliage, but the bacterial endophyte community structure, variation, and assembly across tree ontogeny is unknown. The aims of this study were to test if the core microbiome observed in adult P. flexilis is established at the seedling stage, if seedlings host different endophyte communities in root and shoot tissues, and how environmental factors structure seedling endophyte communities. The 16S rRNA gene was sequenced to characterize the bacterial endophyte communities in roots and shoots of P. flexilis seedlings grown in plots at three elevations at Niwot Ridge, Colorado, subjected to experimental treatments (watering and heating). The data was compared to previously sequenced endophyte communities from adult tree foliage sampled in the same year and location. Seedling shoots hosted a different core microbiome than adult tree foliage and were dominated by a few OTUs in the family Oxalobacteraceae, identical or closely related to strains with antifungal activity. Shoot and root communities significantly differed from each other but shared major OTUs. Watering but not warming restructured the seedling endophyte communities. The results suggest differences in assembly and ecological function across conifer life stages. Seedlings may recruit endophytes to protect against fungi under increased soil moisture.

Nutrient remobilization in tree foliage as affected by soil nutrients and leaf life span

AbstractNutrient remobilization is a key process in nutrient conservation in plants and in nutrient cycling in ecosystems. To predict the productivity of terrestrial ecosystems, we thus need to improve our understanding of the factors that control remobilization. We studied the remobilization rates of several major nutrients (N, P, S, K, Ca, and Mg) in 102 forest ecosystems representing large environmental gradients at the country scale (France). Total amounts or availability of nutrients in soils were correlated with nutrient remobilization: the larger the soil nutrient pool, the lower the remobilization rate (e.g., P remobilization decreased with increasing total or extractable inorganic P in soils). Soil type and soil parent material influenced nutrient remobilization indirectly through their effect on soil nutrients. Nutrient remobilization was also affected by the quality of soil organic matter (C:N and C:P ratios) and K‐Ca‐Mg antagonisms. In addition to soil properties, plant‐related parameters (nutrient concentrations in foliage and leaf life span) and climate variables (e.g., precipitation and actual evapotranspiration) were also correlated with nutrient remobilization. Using multivariate analysis, we found that soil nutrient richness and the life span of the leaf were generally the two most important factors controlling nutrient remobilization. As a whole, the nutrient remobilization rate is regulated by soil nutrients through negative feedback. This general ecological pattern is modulated by ecophysiological constraints of plants, mainly leaf life span or the capability of plants to move Ca through the phloem sap.

Spatial and Temporal Distribution of Soil-Applied Neonicotinoids in Citrus Tree Foliage

Diaphorina citri Kuwayama (Hemiptera: Liviidae) is the insect vector of Candidatus Liberibacter asiaticus (CLas), the presumed cause of huanglongbing (HLB) in citrus (Rutaceae). Soil-applied neonicotinoids are used to manage vector populations and thus reduce the spread of HLB in Florida citrus. Studies were conducted in the greenhouse and field to quantify the spatial and temporal distribution of three neonicotinoid insecticides within individually sampled leaves and throughout the tree canopy. Following field application, no difference in parent material titer was observed between leaf middles versus leaf margins following application of Platinum 75SG or Belay 2.13SC; however, imidacloprid titer was higher in leaf margins than leaf middle following application of Admire Pro. The bottom region of trees contained more imidacloprid than other regions, but was not different from the spherical center region. In the greenhouse, imidacloprid and clothianidin titers peaked 5 wk following application of Admire and Belay, respectively, and thiamethoxam titer peaked 3 wk after application of Platinum. There was no effect of leaf age on uptakes of any insecticides tested. Titers of soil-applied neonicotinoids quantified in the field failed to reach known levels required to kill D. citri. Exposure of D. citri to sublethal dosages of neonicotinoids is of concern for HLB management because of possible failure to protect treated plants from D. citri and selection pressure for development of neonicotinoid resistance. Our results suggest that current soil-based use patterns of neonicotinoids for D. citri management may be suboptimal and require reevaluation to maintain the utility of this chemical class in citrus.

Viewpoint-Driven Simplification of Plant and Tree Foliage.

Plants and trees are an essential part of outdoor scenes. They are represented by such a vast number of polygons that performing real-time visualization is still a problem in spite of the advantages of the hardware. Some methods have appeared to solve this drawback based on point- or image-based rendering. However, geometry representation is required in some interactive applications. This work presents a simplification method that deals with the geometry of the foliage, reducing the number of primitives that represent these objects and making their interactive visualization possible. It is based on an image-based simplification that establishes an order of leaf pruning and reduces the complexity of the canopies of trees and plants. The proposed simplification method is viewpoint-driven and uses the mutual information in order to choose the leaf to prune. Moreover, this simplification method avoids the pruned appearance of the tree that is usually produced when a foliage representation is formed by a reduced number of leaves. The error introduced every time a leaf is pruned is compensated for if the size of the nearest leaf is altered to preserve the leafy appearance of the foliage. Results demonstrate the good quality and time performance of the presented work.

A global comparison of the nutritive values of forage plants grown in contrasting environments

Forage plants are valuable because they maintain wild and domesticated herbivores, and sustain the delivery of meat, milk and other commodities. Forage plants contain different quantities of fibre, lignin, minerals and protein, and vary in the proportion of their tissue that can be digested by herbivores. These nutritive components are important determinants of consumer growth rates, reproductive success and behaviour. A dataset was compiled to quantify variation in forage plant nutritive values within- and between-plant species, and to assess variation between plant functional groups and bioclimatic zones. 1255 geo-located records containing 3774 measurements of nutritive values for 136 forage plant species grown in 30 countries were obtained from published articles. Spatial variability in forage nutritive values indicated that climate modified plant nutritive values. Forage plants grown in arid and equatorial regions generally contained less digestible material than those grown in temperate and tundra regions; containing more fibre and lignin, and less protein. These patterns may reveal why herbivore body sizes, digestion and migration strategies are different in warmer and drier regions. This dataset also revealed the capacity for variation in the nutrition provided by forage plants, which may drive consumer species coexistence. The proportion of the plant tissue that was digestible ranged between species from 2 to 91%. The amount of fibre contained within plant material ranged by 23–90%, protein by 2–36%, lignin by 1–21% and minerals by 2–22%. On average, grasses and tree foliage contained the most fibre, whilst herbaceous legumes contained the most protein and tree foliage contained the most lignin. However, there were individual species within each functional group that were highly nutritious. This dataset may be used to identify forage plant species or mixtures of species from different functional groups with useful nutritional traits which can be cultivated to enhance livestock productivity and inform wild herbivore conservation strategies.

A mimetic nesting association between a timid social wasp and an aggressive arboreal ant

In French Guiana, the arboreal nests of the swarm-founding social wasp Protopolybia emortualis (Polistinae) are generally found near those of the arboreal dolichoderine ant Dolichoderus bidens. These wasp nests are typically protected by an envelope, which in turn is covered by an additional carton ‘shelter’ with structure resembling the D. bidens nests. A few wasps constantly guard their nest to keep D. bidens workers from approaching. When alarmed by a strong disturbance, the ants invade the host tree foliage whereas the wasps retreat into their nest. Notably, there is no chemical convergence in the cuticular profiles of the wasps and ants sharing a tree. The aggressiveness of D. bidens likely protects the wasps from army ant raids, but the ants do not benefit from the presence of the wasps; therefore, this relationship corresponds to a kind of commensalism.

State-Dependent Plasticity in Response to Host-Plant Volatiles in a Long-Lived Moth, Caloptilia fraxinella (Lepidoptera: Gracillariidae)

Volatile chemicals produced by plants mediate host location, mate-finding and oviposition behavior in insects. State-dependent response to plant cues allows for timing of foraging, mating and oviposition on ephemeral host plants or plant parts. Caloptilia fraxinella is a herbivorous specialist on the foliage of ash trees (Fraxinus). Adults are long-lived and undergo a nine-month reproductive diapause over the fall and winter. Mating and oviposition occur in the spring when volatile chemicals released by ash leaves mediate host location. This study tested the plasticity of olfactory response of C. fraxinella to host plant volatiles using both electroantennogram and behavioral bioassays. The effect of moth physiological state on olfactory response was tested on male and female moths in different nutritional, mating, and diapause states. Antennal responses to host plant volatiles were plastic and depended on moth physiological state, and were highest when moths were reproductively active and would be seeking oviposition hosts. Moth sex and nutritional status also impacted antennal response to host plant volatiles. Oriented flight of females to ash seedlings varied with physiological state and nutritional status, with fed, reproductively active females having the highest response. Physiological state impacted oriented flight of males to female-produced sex pheromone signals whether or not a host plant was present, and there was no increase in behavioral response to sex pheromone in the presence of an ash host.

Determinants and correlates of above-ground biomass in a secondary hillside rainforest in Central Vietnam

Despite inception of carbon-conservation forestry programs, information about total above-ground woody biomass (TAGB) in Vietnamese secondary lowland rainforests is still scarce. We elucidated major factors influencing local variation of TAGB within an anthropogenically modified hillside forest in Thừa Thien-Huế Province. On forty 400 m2 sized plots all tree species were recorded, and their biomass was calculated using allometric equations. In addition, bio-physical parameters relating to terrain and soils were measured. Effects of bio-physical variables on forest TAGB were assessed using multivariate regression methods. Forest TAGB (average 117 Mg ha−1) was primarily explained by forest structural variables, i.e. tree densities and average heights, in particular presence of large trees. TAGB was largely determined by the biomass of a few species which dominated different forest parts (ridges or hill base); TAGB was hardly influenced by species diversity. Many dominant trees were light-demanding species; these were characterised by scarce rejuvenation and high tree mortality. Bio-physical patterns indicated that previous logging impacts persisted and continued to influence seedling establishment, sapling growth/survival, and—ultimately—species composition. Nutrient patterns were mostly explained by interactions with certain tree species and tree foliage cover, as modulated by terrain and logging impacts. Development trajectories of TAGB over the next 10–20 years could not be predicted easily since (1) many functionally important late-succession species (e.g. dipterocarps) were very scarce; (2) the sizes of initially established light-demanding species appeared to meet limits, including increasing tree mortality; and (3) rejuvenation and species succession differed locally and proceeded along largely unpredictable pathways. Some suggestions for further research are made.

A New Cretaceous Insect with a Unique Cephalo-thoracic Scissor Device

Insects use different parts of their body to cling to mating partners, to catch prey, or to defend themselves, in most cases the mouthparts or the legs. However, in 400 million years of evolution [1, 2], specialized devices were independently acquired in several groups to adopt these tasks, as for instance modified legs in mantids, assassin bugs or stick insects [3-5], or clasping antennae of the globular springtails [6]. So far, no known species used the neck region between the head and thorax in one of these functional contexts. Here we describe females of †Caputoraptor elegans, a very unusual, presumably predacious insect discovered in approximately 100-million-year-old [7] Burmese amber. Based on several morphological features, we conclude that this species lived in the foliage of trees or bushes. A unique feature of the new taxon is a scissor-like mechanism formed by wing-like extensions on the posterior head and corresponding serrated edges of the dorsal sclerite of the first thoracic segment. Based on the specific structure of the apparatus, we conclude that it was probably used by females to hold on to males during copulation. A defensive or prey-catching function appears less likely. A similar mechanism did not evolve in any other known known group of extant or extinct insects.

Successful Colonization of Lodgepole Pine Trees by Mountain Pine Beetle Increased Monoterpene Production and Exhausted Carbohydrate Reserves.

Lodgepole pine (Pinus contorta) forests have experienced severe mortality from mountain pine beetle (MPB) (Dendroctonus ponderosae Hopkins) in western North America for the last several years. Although the mechanisms by which beetles kill host trees are unclear, they are likely linked to pine defense monoterpenes that are synthesized from carbohydrate reserves. However, how carbohydrates and monoterpenes interact in response to MPB colonization is unknown. Understanding this relationship could help to elucidate how pines succumb to bark beetle attack. We compared concentrations of individual and total monoterpenes and carbohydrates in the phloem of healthy pine trees with those naturally colonized by MPB. Trees attacked by MPB had nearly 300% more monoterpenes and 40% less carbohydrates. Total monoterpene concentrations were most strongly associated with the concentration of sugars in the phloem. These results suggest that bark beetle colonization likely depletes carbohydrate reserves by increasing the production of carbon-rich monoterpenes, and other carbon-based secondary compounds. Bark beetle attacks also reduce water transport causing the disruption of carbon transport between tree foliage and roots, which restricts carbon assimilation. Reduction in carbohydrate reserves likely contributes to tree mortality.

Foliage of tropical arboreal species in feeding ovines (Ovis aries): intake, digestibility and balance nitrogen

Objective: To determine the eff ects of supplementation with three tropical arboreal species (Guazuma ulmifolia, Gliricidia sepium y Tithonia diversifolia) on intake, in vivo and in vitro digestibility in hair sheep. Methodology: Th e experiment was carried out in “Las Brisas” farm of Universidad del Tolima, Colombia. Twelve hair sheep, with an average weight of 22.2±2.5 kg, received four treatments in a 4×4 Latin square design with three sheep per experimental unit were used. Th e treatments consisted of: T1 = 100% D. aristatum; T2 = 50% D. aristatum, 25% Guazuma ulmifolia and 25% rice bran; T3 = 50% D. aristatum, 25% Gliricidia sepium and 25% rice bran; and T4 = 50% D. aristatum, 25% Tithonia diversifolia, and 25% rice bran. To determine the intake and digestibility of nutrients, the method of total collection of feces was used. It was observed that the intake and digestibility of dry matter, organic matter, crude protein, fraction of B3 of the protein and fi ber in neutral detergent, increased in relation to the control group in the diets containing tree foliage (p<0,0001). Main results: Th ere were no diff erences for the dry matter intake (p> 0.05) between the treatments containing tropical arboreal species G. ulmifolia (T2), G. sepium (T3) and T. diversifolia (T4). However, diff erences were observed between all treatments (p <0.05) for nutrients digestibility. Conclusion: Th e supplementation of hair sheep with foliage of tropical arboreal species is an interesting alternative to improve the intake and digestibility of diets which can contribute tothe improvement of the productive indicators.

HEAVY METAL CONTENT IN SOD-PODZOLIC SOIL AND IN THE VEGETATION OF FOREST, MEADOW AND FIELD PHYTOCENOSES

The content of heavy metal salts (copper, zinc, cadmium and lead) was determined in the soil and the vegetation of forest, meadow and field phytocenoses located on the trial field of Perm Agricultural Research Institute. The studies were fulfilled in 2012-2014. The soil in all the studied phytocenoses was sod-podzolic with a different degree of podzolic process evidence. The studied plant material consisted of pine needles and the foliage of trees, the grass of natural meadow and the green mass of Galega orientalis.The content of heavy metals in the soil and plants of all the phytocenoses was significantly lower than the MPC (maximum permissible concentration), except for the copper content in the forest phytocenoses located at a distance of 100-200 m from the federal highway. The concentration of copper and zinc increased with time: in 2014 the content of copper and zinc doubled and tripled respectively as compared to 2012. The lead content did not change considerably and was significantly lower than the MPC for all the studied phytocenoses. The tendency towards some increase of heavy metal content in the soil and vegetation cannot be an obstacle for scientific research in the examined areas.