Fruit-bearing Shrub Research Articles

Potential of Sea Buckthorn (Hippophae rhamnoides L.) Thickets in Preserving Endangered Ecosystems in Kyrgyz Republic

Intensive urbanization from year to year reduces natural ecosystems that play a huge balancing ecological role on the planet. Preservation of natural ecosystems bordering on cultivated ones requires the development of new approaches to mutually beneficial sustainable development. Great potential lies in the preservation of unique ecosystems with wild fruit-bearing plantations. In this article, using the example of the natural ecosystems of the shores of Lake Issyk-Kul, included in the list of Ramsar Convention on the Conservation of Wetlands, the possibility of using natural thickets of sea buckthorn to improve the socio-economic situation of the local population and preserve unique but endangered natural ecosystems is analyzed. Studies have shown that sea buckthorn (Hippophae rhamnoides L.) fruits do not accumulate heavy metals and contain an increased content of ascorbic acid. A survey of the local population showed that local residents do not consider the use of sea buckthorn plantations as a potential source of income, but recognize it as the most environmentally friendly. In order to develop the mutually beneficial development of the local population and natural ecosystems, it is necessary: to use wild-growing fruit-bearing shrubs with the maximum benefit from the annual harvest, among which the sea buckthorn (Hippophae rhamnoides L.) has a potential; to develop recommendations and modern technologies for the production of a wide range of products, using all possible parts of sea buckthorn; educate local people on the importance of preserving natural ecosystems and involve local businessmen in preserving vulnerable ecosystems.

Pomegranate (punica granatum): a comprehensive review of its medicinal properties and traditional uses and prospect in wellness industry

Pomegranate (Punica granatum) is a fruit-bearing shrub with a rich history of traditional use in various medicinal systems. This review paper aims to provide an in-depth analysis of the botanical profile, medicinal properties, and applications of pomegranate. Additionally, it explores its significance in traditional medicine systems, including Ayurveda, Chinese medicine, American Indian medicine, and the Usadha Taru Premana palm manuscript—a revered Balinese medicinal palm manuscript, and The Holy Quran. The review highlights the active compounds, therapeutic potential, regional variations, cultivation, culinary uses, and its emerging role in the tourism and wellness industry.

Advancements in Mutation Breeding in Phalsa (Grewia asiatica L.) Crop Improvement: A Comprehensive Review of Radiation and Chemical Induced Mutagenesis Studies

Phalsa (Grewia asiatica L.), a member of the Tiliaceae family, is a remarkable fruit-bearing shrub with significant medicinal and nutritional value. Originating in South Asia, it has gained popularity worldwide, particularly in subtropical and tropical regions. This review comprehensively examines the botanical characteristics, medicinal properties, nutritional composition, cultivation practices, and challenges faced by Phalsa growers, with a focus on its potential for crop improvement through mutagenesis and polyploidization techniques. With around 150 species, Grewia is the sole genus in the Tiliaceae family that produces edible fruit. Phalsa bushes, known for their rapid growth, yield orbicular fruits with moderately acidic yet nutritious pulp. The fruit is esteemed for its medicinal benefits, ranging from anti-inflammatory and anti-diabetic properties to its use in treating various respiratory and cardiovascular ailments. Despite its nutritional and medicinal significance, Phalsa cultivation faces challenges such as poor post-harvest management, limited germplasm diversity, and abiotic stress susceptibility. To address these challenges and enhance Phalsa's agricultural potential, mutagenesis and polyploidization techniques have been explored. Induced mutagenesis offers a promising avenue for creating genetic diversity and improving traits such as stress tolerance and disease resistance. However, culture contamination remains a significant obstacle in achieving optimal shoot initiation and propagation efficiency. Overall, this review underscores the importance of Phalsa as a valuable crop with immense medicinal and nutritional benefits. By leveraging mutagenesis, polyploidization, and tissue culture techniques, Phalsa growers can overcome existing challenges and unlock its full agricultural potential, contributing to food security and public health.

Phytochemical screening and antimicrobial activity of plant leaf extract against enteric bacterial pathogens

Punica granatum, a fruit-bearing shrub belonging to the Lythraceae family, offers various benefits to humans, with both its fibers and seeds being valuable. The seeds contain important oil acids such as palmitic, punica, stearic, and oleic acids. In India, P. granatum (pomegranate) leaves have been investigated for their potential antibacterial activity against enteric pathogens. These pathogens are responsible for causing gastrointestinal infections and are often associated with antibiotic resistance. The study aims to explore whether pomegranate leaves possess properties that can combat these enteric pathogens effectively. This research holds promise in identifying a natural and alternative approach to address antibacterial challenges, potentially contributing to the development of novel antimicrobial agents pomegranate is commonly used as a traditional remedy for treating enteric bacterial pathogens. To investigate its antibacterial properties, researchers studied the aqueous extract of P. granatum leaf against enteric pathogens, conducting tests like biochemical examinations and microscopy on the isolates. The phytochemical analysis of P. granatum (pomegranate) leaf aqueous extract revealed the presence of various bioactive compounds. These compounds include amino acids, carbohydrates, alkaloids, steroids, flavonoids, terpenoids, saponins, tannins, and phenols. To evaluate its antimicrobial activity, the researchers used antibiotic discs, including chloramphenicol, vancomycin, and gentamicin, employing the standard Kirby Bauer method. Results showed that vancomycin had the highest zone of inhibition, followed by chloramphenicol and gentamicin, with respective measurements of 20 mm and 19 mm. Chloramphenicol exhibited sensitivity against Escherichia coli (19 mm), while gentamicin showed sensitivity against Salmonella typhi (20 mm), Staphylococcus aureus (19 mm), and E. coli (18 mm). Vancomycin demonstrated sensitivity against S. aureus (21 mm). The aqueous leaf extract displayed significant antibacterial activity at concentrations of 20, 40 mcg, and 60 μg, showing effective zones of inhibition ranging from 15 mm to 22 mm against Pseudomonas aeruginosa, E. coli, S. aureus, Shigella dysentriae, Proteus vulgaris, and S. typhi. In conclusion, the study established that P. granatum leaf extracts possess remarkable antibacterial properties and contain valuable pharmaceutical bioactive compounds. Due to its efficacy in treating gastrointestinal disorders, it is utilized as a natural remedy in traditional medicine.

Determination of Uranium Concentrations and 234U/238U Isotopic Ratios in Plants and the Groundwater Used in Their Cultivation in an Area with High Background Radiation

The weathering of rocks and soil causes uranium to collect in groundwater. In this article, we attempted to assess the activity concentrations of uranium and 234U/238U isotopic ratios in various groundwater samples and plants obtained from the Ha’il region, Saudi Arabia. The results showed that the concentrations of 238U ranged between 0.08 ± 0.04 and 1.11 ± 0.06 Bq L−1, with an average of 0.67 ± 0.05 Bq L−1. Activity concentrations of 234U ranged between 0.12 ± 0.01 and 2.2 ± 0.8 Bq L−1, with an average of 1.26 ± 0.11 Bq L−1. The international permissible limit of uranium in groundwater is 0.372 Bq L−1. The 234U/238U activity ratios in the collected groundwater samples ranged between 1.5 ± 0.09 and 2.49 ± 1.27 Bq L−1, with an average of 1.95 ± 0.52 Bq L−1. In fruit-bearing trees, the 234U/238U activity ratios were 1.57 ± 0.84, 2.58 ± 1.01, and 2.69 ± 0.95 Bq L−1 for lemon, fig, and narenj. In fruit-bearing shrubs, the 234U/238U activity ratios were 2.37± 0.69 and 2.68 ± 0.69 Bq L−1 for green pepper and eggplant. Our goal is to increase the understanding of the factors that govern uranium’s activity and isotopic composition to better understand its prospective utilization as a tracer in groundwater chemistry and hydrology, as well as the possibility of exploiting this area for irrigation. In this investigation area, the groundwater and plants were unfit for human consumption.

The parasitisation of the rose tortrix [Archips rosana (L.)] Population in the apple orchard in the Wielkopolska region, Poland

The rose tortrix is a polyphagous species, which is dominant in the leafroller complex (Tortricidae) in orchards, including apple orchards and fruit-bearing shrubs in western and southeastern Poland. Rose tortrixes massively feed on leaf rosettes, developing leaves, buds, flowers and fruit buds in orchards. The population of this phytophage is regulated by environmental factors such as its natural enemies, e.g. parasitoids. The aim of the study was to determine the degree of parasitisation of rose tortrix pupae and to determine the role of individual families of parasitoids in reducing their population. The study showed that parasitoids from the Ichneumonidae, Chalcididae, Tachinidae, Euliphidae and Pteromalidae families reduced the rose tortrix population. The parasitoids of the Ichneumonidae family were the most effective entomophages. The degree of total parasitisation of rose tortrixes in individual years of the research was similar.
 The effectiveness of these entomophagous parasitoids is influenced by environmental factors – above all by weather conditions, the number of crop protection treatments and the ecological infrastructure of orchards.

Interactive climate-soil forces shape the spatial distribution of foliar N:P stoichiometry in Vaccinium uliginosum planted in agroforests of Northeast China

In regions with a ban on forest logging, fruit-bearing shrubs are favored as an alternative source of ecological products over the harvesting of timber. The introduction of cultured shrubs from their habitat to newly developed lands has to be decided according to nutrient availability. Foliar nitrogen (N) and phosphorus (P) stoichiometry is an easily measured and reliable parameter to quickly indicate possible limits in imbalanced N-P availability. When attempting to create a spatial distribution map of the foliar N:P ratio in an objective shrub species, it is helpful to first explore its potential acclimation to the N:P imbalance caused by the joint forces of soil property and regional climate. This study evaluated the cultivated populations of Vaccinium uliginosum in northeastern China's agroforests, using Vaccinium uliginosum as a model shrub species. A total of 51 populations were selected from 51 managed stands, of which 34 were in forests and 17 on farmlands. Foliar N and P concentrations, soil physical and chemical properties, and topography were investigated in 2018, and regional climatic factors were assessed by averaging previous 5-year records (2013–2018). V. uliginosum was determined to have a foliar N:P ratio lower than 4.4, which can be characterized as a limit of N relative to that of P. On forested lands, soil pH negatively impacted regressed foliar N:P, which was also part of the contributions of soil total P content and average temperature to foliar N concentration. On farmlands, low soil pH also resulted in a reduced foliar N:P ratio with joint contributions of ammonium N, nitrate N, and available P contents in soils and air humidity. Spatial interpolation indicated that western forests could benefit from introduced V. uliginosum with a higher foliar N concentration, while the introduction to eastern farmlands can lead to a higher foliar N:P ratio up to 14.6. Our study demonstrates recommended locations with expected soil and meteorological conditions by mapping spatial distributions, which can be referred to by other species and regions.

Comparative metabolic study of Citrus sinensis leaves cultivars based on GC–MS and their cytotoxic activity

Citrus sinensis L. Osbeck, (family Rutaceae), known as sweet orange, is a fruit-bearing shrub that widely cultivated all over the world due to its nutritive value, nutraceutical attributes and economic importance. In the present study, a comparative metabolic profile study of the essential oils of the leaves of nine cultivars of Citrus sinensis cultivated in Egypt was carried out based on GC–MS analysis coupled to chemometrics. A total of 47 compounds were identified, where monoterpenes hydrocarbons (61.39 %–78.26 %) represented the main recognized class in the essential oils. Sabinene (8.25 %–28.81 %), 2-carene (11.25 %–16.72 %) and cis-β-ocimene (10.22 %–13.93 %) were the major components identified in different cultivars. Chemometric analyses comprising Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) were experienced for their ability to discriminate between closely related cultivars. Both PCA score plot and HCA dendrogram could successfully segregate different cultivars based on their metabolic profiles. The MTT assay was used to evaluate the cytotoxicity of essential oils of Citrus sinensis leaves cultivars on different cell lines; MCF-7, HepG-2, HeLa, were all essential oils showed moderate cytotoxic activity. The MCF-7 cell lines were the most resistant cells with IC50 range from 243 to 343 μg/mL, while HeLa cells were the most sensitive cell lines IC50 range from 203 to 283 μg/mL. This may be attributed to the synergistic effects of different chemical components.

Effects of food availability on the trophic niche of the hazel dormouse Muscardinus avellanarius

The scale at which variations in food availability affect the foraging habits of individual animals can determine how the distribution of food resources affects populations. For species of conservation concern, these factors can have important implications for the management of habitats, as spatial and temporal variations in resource availability influence the trophic ecology of both individuals and populations. The hazel dormouse Muscardinus avellanarius is a species with seasonal dietary shifts and limited ranging, and whose populations in Great Britain are exhibiting marked decline, despite conservation measures. We compared resource availability and variation in dormouse traits with their trophic characteristics, determined by stable isotope analysis of dormouse hair and of their putative food items.The trophic levels of individual dormice were associated with the abundance of invertebrates in the surrounding habitat and in the woodland as a whole. Assessment of dormouse dietary composition suggests that the proportions of invertebrates and of tree seeds and flowers in dormouse diets are affected by the abundance of food plants in the local habitat. This suggests that dormice can exploit both invertebrates and plants in proportion to their availability, and are variable in their predatory habits, in response to both the availability of invertebrates and plants.Dormouse populations exhibit a broader trophic niche in autumn than in spring, most likely a consequence of their consumption of foods derived from a wider variety of tree and shrub species. We found no relationship between isotope signatures or food availability and the body mass or torpor of individuals, or the status of populations. This may be because, on the sites we studied, dormice could adapt to different food availabilities without discernible individual and population effects.Dormice are opportunistic feeders, rather than specialists, making use of abundant food resources at a local scale. Habitat conservation for dormice, therefore, could benefit from establishing and maintaining habitats that increase the overall abundance and uniform distribution of both flower and fruit-bearing shrubs and trees and invertebrate populations, at a fine spatial scale.

Molecular and functional characterization of two isoforms of chalcone synthase and their expression analysis in relation to flavonoid constituents in Grewia asiatica L.

Chalcone synthase constitutes a functionally diverse gene family producing wide range of flavonoids by catalyzing the initial step of the phenylpropanoid pathway. There is a pivotal role of flavonoids in pollen function as they are imperative for pollen maturation and pollen tube growth during sexual reproduction in flowering plants. Here we focused on medicinally important fruit-bearing shrub Grewia asiatica. It is a rich repository of flavonoids. The fruits are highly acclaimed for various putative health benefits. Despite its importance, full commercial exploitation is hampered due to two drawbacks which include short shelf life of its fruits and larger seed volume. To circumvent these constraints, seed abortion is one of the viable options. Molecular interventions tested in a number of economic crops have been to impair male reproductive function by disrupting the chalcone synthase (CHS) gene activity. Against this backdrop the aim of the present study included cloning and characterization of two full-length cDNA clones of GaCHS isoforms from the CHS multigene family. These included GaCHS1 (NCBI acc. KX129910) and GaCHS2 (NCBI acc. KX129911) with an ORF of 1176 and 1170 bp, respectively. GaCHSs were heterologously expressed and purified in E. coli to validate their functionality. Functionality of CHS isoforms was also characterized via enzyme kinetic studies using five different substrates. We observed differential substrate specificities in terms of their Km and Vmax values. Accumulation of flavonoid constituents naringenin and quercetin were also quantified and their relative concentrations corroborated well with the expression levels of GaCHSs. Further, our results demonstrate that GaCHS isoforms show differential expression patterns at different reproductive phenological stages. Transcript levels of GaCHS2 were more than its isoform GaCHS1 at the anthesis stage of flower development pointing towards its probable role in male reproductive maturity.

Gene pool of less widely spread fruit tree species

Within the gene pool collected at the Department of Breeding and Propagation of Garden Plants of the Faculty of Horticulture, Mendel University of Agriculture and Forestry in Brno, in Lednice we established experimental plots with some selected less known tree species - quince (Cydonia oblonga Mill.), sea buckthorn (Hippophäe rhamnoides L.), Cornelian cherry (Cornus mas L.) and honeysuckle (Lonicera caerulea subsp. edulis Turcy. ex Freyn.). The experimental plots were established in successive steps according to the availability of planting material and using conventional methods of cultivation. Evaluations are focused on selected growth parameters, phenology and commercial use of the fruit.The evaluations of the crown of quince showed differences in the size and shape. The variety Hemus had the largest crown volume (5.70 m3); the variety Blanár gave the highest harvest yields. The sea buckthorn varieties Polmix, Dar Katuni and Novosť Altaja produced the longest increments. The average weight of the fruit of the variety Leicora was 0.74 g. The varieties of Cornelian cherry also differed in the growth parameters; the highest shrubs were those of the variety Vyšegorodskij, which also produced the largest fruit – the average weight of the fruit was 4.85 g. The initial growth of selected varieties and genotypes of honeysuckle is different when compared to the fruit-bearing shrubs. Harvest data are in direct proportion to the size of the shrub. Fruit harvest began in mid-May and vegetation ended on 15 October.

The effect of nitrogen treatment on the anthacyanine and polyphenols content and ORAC factor of Aronia melanocarpa grown in Maryland (1042.5)

Black chokeberry or Aronia melanocarpa is a small fruit‐bearing shrub in the rose family. Although it is native to Maryland, its range nowadays is from Newfoundland, west to Ontario, south into Alabama, and east to Georgia, and hardy to Zone 3. Aronia is a landscape quality plant, susceptible to few pests and diseases that persist in soils and temperate climatic conditions. It is an ideal candidate for organic fruit production. The Aronia fruit has nutraceutical qualities, heightening its marketability and sales potential as a value‐added product. There is currently great interest in fruits and vegetables that contain high concentrations of flavonoids, considered potent antioxidants. Some recent studies have implicated the relationship between in‐field plant nutrient fertility and antioxidant production in aronia. Here we present the data for the antioxidant content of Aronia melanocarpa as a function of the difference of age, amount of time spent in the sun or shade, and nitrogen treatment levels of crops. We have shown that the level of nitrogen treatment in the soil influences the antioxidant capacity significantly. Detailed measurements and analysis of anthocyanin and polyphenols as well as ORAC factor will be presented and discussed. The aim of the project is to determine the treatment that produces the highest capacity of antioxidants in aronia.Grant Funding Source: Supported by Grant T34GM008411, from the National Institute of General Medical Sciences

The Value of Native and Invasive Fruit-Bearing Shrubs for Migrating Songbirds

The success of annual migrations for songbirds is greatly affected by habitat quality at stopover sites, particularly in relation to food needed for rapid refueling. The abundance and nutritional quality of important food resources may be linked to the presence of deciduous shrub species that provide seasonal fruits in the fall and support insects in the spring. The objective of this study was to determine whether migrating songbirds benefit from resources provided by native or invasive fruit-bearing shrubs found at 2 bird-banding stations in Rochester, NY. We conducted nutritional analyses (energy density, fat content, total soluble solids) on the fruits of common shrub species at the study sites, monitored removal of the fall fruits of focal native and invasive shrub species in the field, and measured the abundance of midges—a common insect resource for migrating songbirds— supported by the focal shrub species in the spring. The highest fat content and energy densities were found in fruits of native shrubs, ranging from 6.57 to 48.72% fat and 18.83 to 28.68 kJ/g of energy. All invasive fruits had ≤0.99% fat and ≤17.17 kJ/g of energy. We also found a significant positive correlation between fat and energy content of the fruits. Native dogwood fruits were consumed by migrating songbirds at higher rates than invasive fruits over the fall migration period. However, there was no clear pattern of midge abundance between native and invasive shrub species during the spring migration period. Our results suggest that fruits of native shrubs are of greater nutritional value to migrating songbirds than the fruits of invasive shrubs during fall migration, which is supported by the higher removal rates by songbirds of native dogwood fruits than fruits of the 4 other invasive fruit species. This finding suggests that removal of invasive fruit-bearing shrubs or plants will not negatively impact migrating birds when high-quality native fruit-bearing shrubs are available. However, additional study on the relative value of these shrubs in the spring and over multiple seasons is needed to provide insight into their overall value for birds during annual migrations.

DISTRIBUCIÓN Y CARACTERIZACIÓN ECO-CLIMÁTICA DEL MEMBRILLO CIMARRÓN (Amelachier denticulata (Kunth) Koch) EN MÉXICO

The Southern false serviceberry (Amelanchier denticulata (Kunth) Koch) is a fruit-bearing shrub native to Mexico, and there are not enough studies about the use, distribution, and diversity. This research aimed to make a distribution model and eco-climatic characterization as well as current and future models of suitable areas for cultivation of A. denticulata using Geographical Information Systems (GIS). The southern false serviceberry was distributed mainly in central Mexico. Three eco-climatic groups were found; group 1 showed climate C, group 2 climate A(C), and group 3 climate Bs. The most suitable regions of cultivation were Guanajuato, Queretaro, and Hidalgo. This research will serve as basis of planning the best conservation strategy of A. denticulata genetic resources and to design the correct way of collection. The three different climatic groups should have diverse germplasm, which is important collect from each group. The best regions to establish in vivo germplasm bank are northeast Guanajuato, central and southern Queretaro, and southern Hidalgo.

The effects of partial cutting on the Rose-breasted Grosbeak: abundance, food availability, and nest survival

Periodic partial harvesting of trees is an important economic activity within the highly fragmented woodlands of southern Ontario. We studied the population density, age structure, food abundance, productivity, and nest survival of Rose-breasted Grosbeaks (Pheucticus ludovicianus) nesting in 35 deciduous woodlots with varying intensities of harvest. Heavily cut woodlots contained higher densities of territorial males and greater abundances of fruit-bearing shrubs compared with standard cut and reference sites (uncut for >13 years). Results based on insect sampling were mixed, depending on the sampling technique and sample date. All treatments were demographic sinks, with populations in this landscape showing annual declines of 19%–24%. Though the proportion of parasitized nests tended to be higher in heavily cut sites, harvesting had little effect on nest survival, nest initiation dates, clutch size, age structure, or the number of young fledged from a successful nest. Our results indicate that within the fragmented woodlots of southern Ontario, partial harvesting does not further degrade breeding habitat for Rose-breasted Grosbeaks. However, further research is needed to determine the underlying causes of population declines.

Estimating inoculum production relative to percent leaf area infected and environmental conditions required for stimulating release of Entomosporium mespili conidia on Amelanchier alnifolia

Amelanchier alnifolia, commonly known as saskatoon, is a fruit-bearing shrub native to the Canadian Prairies. Currently, production is limited by the fungal pathogen Entomosporium mespili. It was found that there is a positive linear relationship between the relative concentration of E. mespili conidia (X) and the percent of saskatoon leaf area that is infected (Y), as represented by the equation Y = 0.0534X. In a field study, initial disease symptoms appeared 5 d after the first precipitation event that occurred 1 d or more after the date of flowering. A splash-dispersed-conidia trap was constructed and used to trap conidia within the canopy of a saskatoon plant and, in both years of this study, conidia were first trapped on the 184th day of the year, which coincided with the exponential increase of percent leaf area infected. Conidia were primarily released during the first 2 h of precipitation events. Information on inoculum production and release will eventually be integrated into a dynamic disease-forecasting model for entomosporium leaf and berry spot caused by E. mespili on saskatoon.

Hawthorn: pharmacology and therapeutic uses.

The uses, pharmacology, clinical efficacy, dosage and administration, adverse effects, and drug interactions of hawthorn are discussed. Hawthorn (Crataegus oxyacantha) is a fruit-bearing shrub with a long history as a medicinal substance. Uses have included the treatment of digestive ailments, dyspnea, kidney stones, and cardiovascular disorders. Today, hawthorn is used primarily for various cardiovascular conditions. The cardiovascular effects are believed to be the result of positive inotropic activity, ability to increase the integrity of the blood vessel wall and improve coronary blood flow, and positive effects on oxygen utilization. Flavonoids are postulated to account for these effects. Hawthorn has shown promise in the treatment of New York Heart Association (NYHA) functional class II congestive heart failure (CHF) in both uncontrolled and controlled clinical trials. There are also suggestions of a beneficial effect on blood lipids. Trials to establish an antiarrhythmic effect in humans have not been conducted. The recommended daily dose of hawthorn is 160-900 mg of a native water-ethanol extract of the leaves or flowers (equivalent to 30-169 mg of epicatechin or 3.5-19.8 mg of flavonoids) administered in two or three doses. At therapeutic dosages, hawthorn may cause a mild rash, headache, sweating, dizziness, palpitations, sleepiness, agitation, and gastrointestinal symptoms. Hawthorn may interact with vasodilating medications and may potentiate or inhibit the actions of drugs used for heart failure, hypertension, angina, and arrhythmias. The limited data about hawthorn suggest that it may be useful in the treatment of NYHA functional class II CHF.

Topology, scaling relations and Leonardo's rule in root systems from African tree species.

Aspects of root architecture, including topology, link length, diameter and scaling relations, were analyzed in excavated coarse root systems of three field-grown fruit tree species (Strychnos cocculoides Bak., Strychnos spinosa Lam. and Vangueria infausta Burch) and the fruit-bearing shrub Grewia flava DC. We investigated the root systems using semi-automatic digitizing and computer-based 3-D reconstruction techniques. Topological analysis was carried out to investigate branching patterns as basic determinants of root architecture. New topological indices were developed and revealed significant differences among the species. The different architectural strategies can be explained in terms of cost-benefit relations and efficiency in soil resource exploration and exploitation. In addition, some well-known hypotheses about geometry and scaling, most of them previously unverified by empirical observations on root systems, were tested. For practical applications, the main emphasis is on the relationship between proximal root diameter, an easily determined parameter, and several parameters describing the size of the whole root system. We also tested the "pipe stem" theory, essentially dating back to Leonardo da Vinci, which underlies many models and which we found conformed to our measurement data with reasonable accuracy. A physiological consequence of the "constant cross-sectional area rule" may be a certain homogeneity of hydraulic architecture throughout root systems.

USE OF SUCCESSIONAL HABITAT AND FRUIT RESOURCES BY SONGBIRDS DURING AUTUMN MIGRATION IN CENTRAL NEW JERSEY

Abstract We evaluated the effects of plant succession on habitat use and fruit resource availability for autumn migratory and resident songbirds in 43 ha of abandoned farm fields in central New Jersey. Using fixed net sites, standardized effort, and simultaneous sampling across habitat types, we mist-netted birds to compare habitat use and found that (1) use of three shrub-tree invasion interfaces declined as fruit-bearing shrubs were overgrown by trees, while use of three open shrublands changed little over the same period; (2) use of two pairs of contrasting successional habitats, shrubland and young woodland, was higher in the shrubland with abundant, highly nutritional fruits than in young woodland with sparse fruit; and (3) use of three shrublands at similar successional stages but with different fruit availability differed by bird taxonomic family and migratory strategy. Data on species composition and relative abundance of fruit-bearing shrubs and fruit consumption by birds (assessed by regurgitate...