Hedgerow Types Research Articles

A review of the ecology of butterflies in British hedgerows

In examining the influence of hedges on butterflies it is appropriate to consider the whole hedgerow complex, which may include verges and other adjacent land. This paper examines our knowledge of the role that hedgerows play in the ecology of butterflies in Britain. In general, the butterfly fauna of hedgerows consists mainly of common species although species richness is potentially high with 39 species (64% of the British list) being recorded from hedgerows. Optimum butterfly habitats such as unimproved grassland and coppiced woodland occupy only a tiny fraction of Britain and hedgerows may provide surrogate habitat for butterflies of such habitats in the wider countryside. We discuss the species typical of hedgerow habitats, the factors that affect butterfly distribution within hedgerows, their role as movement corridors and barriers, the relative merits of different hedgerow types and management suitable for butterflies. An improved understanding of how hedgerow management affects butterflies is required to ensure that the biodiversity potential of this widespread habitat is optimised in the wider countryside.

A comparison of four methods used to survey hedgerows: The Cardiff Hedgerow Survey 1998

One of the aims of the Cardiff Hedgerow Survey 1998 was to compare the results from four different survey techniques on the same hedgerows. A stratified sample of 211 hedgerows was surveyed using standard 30-m lengths, 10-m plots, the Hedgerow Evaluation and Grading System (HEGS), and features of importance as defined in the UK Government’s Hedgerows Regulations 1997.All methods identify variation between hedgerows which can be used to differentiate between hedgerow types (e.g. parish/community boundaries, new hedgerows), or compare hedgerows in different areas (e.g. communities). The number of species in 10-m lengths, 30-m lengths and the whole hedgerow were highly correlated; surveys of sections can thus indicate overall species richness, though 30-m lengths gave better results than 10-m lengths. In general a good relationship between HEGS and the ‘importance’ as defined by the Hedgerows Regulations was found, but it was not predictive for middle-ranking hedgerows, and the HEGS method cannot be used in proxy for the Hedgerows Regulations or vice versa. General surveys can be carried out using these two methods together to maximise both ecological and contextual information collected during surveys.

The influence of hedge structure, management and landscape context on the value of hedgerows to birds: A review

In this review, we discuss the value of hedgerows as bird habitat in lowland-farming landscapes to provide a background against which decisions concerning hedgerow management might be evaluated. The two most important factors positively associated with species richness and abundance of breeding birds in hedgerows are hedge size (height/width/volume) and the presence/abundance of trees. The provision of cover and the botanical and structural complexity of the vegetation are also important. However, large hedges do not suit all species; birds tend to prefer hedgerow types which most closely resemble their usual non-hedgerow breeding habitat. The value of hedgerows to birds can be increased by combining them with other features such as headlands (for game birds), verges, wildflower strips, game and wild-bird cover and well-vegetated banks and ditches. The presence of well-grown, dead or decaying trees is beneficial to many species, providing nest holes, foraging sites and perches. Increasing the structural complexity of a hedgerow and its associated habitat may also reduce the incidence of predation. Hedgerows also provide physical shelter and roost sites and are an important source of winter food supplies, especially berries and other fruits. Some bird species, usually those whose primary habitat is woodland, live mainly within the hedgerow itself, whereas others are more dependent on the surrounding landscape to a greater or lesser extent. However, even the presence of woodland bird species is influenced by the availability and characteristics of alternative habitats in the surroundings and therefore hedgerows and their bird populations do not function as isolated patches. As linear landscape elements, hedgerows also provide safe cover for both local and larger-scale movements and may facilitate access to resources or habitat which might otherwise be too risky or too remote for birds to use or colonise. A number of recommendations for improving hedgerow habitat for birds are reiterated from an extensive literature and include combining hedgerows with other semi-natural habitat, providing a variety of structural types, maintaining good cover in the hedge-base, e.g. by excluding stock and herbicide, and avoiding excessive cutting. However, good hedgerow management has costs and is unlikely to be applied widely in the absence of national policy and funding.

A modelling strategy to design hedgerow barrier systems for water conservation in the Sahel

Heterogeneity in space and time makes it difficult to evaluate the hydrologic effects of hedgerows in between crops. In this study a robust modelling system for designing hedgerow barrier systems is introduced. The system is demonstrated with experimental data over three years from a site in central Burkina Faso. Soils at the site are prone to crusting and consist of a sandy loam in the top layer and clay in deeper layers. Measurements comprise runoff from differently sized plots (1, 5 and 10 square meters), water storage into the soil, and rainfall. It appears that the relevant hydrologic processes can be represented with the available measurements by two compact dynamic models, each comprising two states (runoff and soil water; water use and soil water), one input (rain; potential evapotranspiration) and two spatial units (hedgerow and cropped area). The analysis of the phase planes of the models reveals which combinations of alley length and hedgerow type lead to desirable combinations of both runoff and evapotranspiration. This information can be interpreted directly in a qualitative sense or alternatively used for a Monte-Carlo analysis of the system.

Hedgerows and mulch as soil conservation measures evaluated under field simulated rainfall

Hedgerows and residue cover have been reported as successful practices to reduce soil and water losses on steep lands. However, there is a lack of information on the efficiency of hedgerow types, hedgerow-mulch interaction and the effect of soil moisture and slope (gradient and length) on the overall performance of these practices. Results from four experiments using Vetiver and other grasses under simulated field conditions in Venezuela are presented. The experiments were conducted in the mountain coastal range of Venezuela, at 1800 m above sea level, where intensive horticultural systems occupy steep lands. A double nozzle rainfall simulator, yielding an average intensity of 55.6 mm h −1 was used on 5 m length and 0.5 m wide plots, on an Aquic Paleudult soil with different soil moisture conditions and two 15% and 26% slopes, in order to evaluate the efficiency of five 50 cm wide hedgerows: Vetiver ( Vetiveria zizanioides), Lily ( Agapanthus africanus), Fern ( Nephrolepis sp.), Lemon grass ( Andropogon citratum) and no hedgerow; and five levels of pine needles residues: 0, 0.5, 1.5, 3 and 5 Mg ha −1. Upland flow was simulated using a flow equal to an 80% rainstorm runoff as obtained under wet and very wet conditions, in order to imitate equivalent slope lengths. Hedgerows and mulch were good conservation measures, especially when they were combined. Vetiver grass and Fern were the more efficient hedgerows because of their highly dense vegetative structure. Residue requirements are less when the slope is protected by hedgerows. Larger intervals between hedgerows would be possible provided there is mulch between hedgerows. A table is presented as a guideline to design hedgerows spacing considering rainfall erosivity, soil erodibility and crop-management intensity.

スピードスプレーヤのわい化リンゴ園用噴頭の開発

This investigation was carried out to develop air jet outlets attached to speed sprayers for hedgerow type apple orchards, and to obtain a suitable way of application.The results are as follows:1) Two kinds of air jet outlets to be attached to a commercially manufactured spped sprayer were made on an experimental basis. They had 55 degree spray angle on each side, which was suitable for spraying trees about 3m high.2) The 85mm width outlet (type II) had 20% higher air velocity and 30% larger air horse power than the 120mm width outlet (type I). The former outlet produced better results in spray performance.3) Judging from the spray distribution, the suitable application rate in hedgerow orchards is from 40 to 50% of that in traditional orchards, thus conserving dilution water, agricultural chemicals and labour.4) The suitable application width is 8m for both 1 and 3-row planting. Uniform spray distribution and sufficient work efficiency can be obtained, by the customary operation speed.

The diet and foraging behaviour of the Dunnock Prunella modularis in a hedgerow habitat

The diet and foraging behaviour of a population of Dunnocks inhabiting hedgerows was studied between November 1981 and December 1983 at Nedge Hill, Shropshire. Invertebrates were most abundant in hedgerows and adjacent vegetation during the summer when the diet of the Dunnock was largely insectivorous. Beetles (Coleoptera) were the main taxa in the diet, with weevils (Curculionidae) and rove beetles (Staphylinidae) predominating. Arachnids were important, and snails (Gastropoda), earthworms (Oligochaeta), springtails (Collembola) and flies (Diptera) were taken. Seeds were available in the study area from July and featured in the diet from August to April. Nettle Urtica dioica comprised the main seed in the diet. Other important seeds included Yorkshire fog Holcus lanatus, elder Sambucus nigra and dock Rumex obtusifolius. Stomach stones were most common in the faeces in winter. The Dunnocks were predominantly ground feeders and mainly used a hop‐picking technique. Some seeds and invertebrates were picked directly off plants by Dunnocks above the ground. Most feeding occurred in hedgerows, which formed a small proportion of the study area. Overgrown hedgerows were the most important of the five hedgerow types. Nettle patches were an important feeding habitat. Dunnocks usually foraged alone or in pairs and rarely fed in association with other bird species. The highest proportion of time spent feeding was in January and the lowest in May.

The design of a prototype apple harvester

Previous methods of harvesting apples mechanically are reviewed briefly. A novel method of removing apples by a combing technique is then discussed. The design of a prototype harvester capable of harvesting dessert quality fruit continuously from hedgerow type trees, utilizing this combing technique, is described in detail.

Captan Deposition in Peach Orchard Hedgerows1

Abstract Four hedgerow types: oblique fan, canted oblique fan, modified central leader, and open center, in a peach (Prunus persica (L.) Batsch cv. Olinda) orchard were evaluated in 1975 and 1977 for their effect on deposition of captan (N-trichloromethyl-4-cyclohexene-l,2,dicarboximide). Within hedgerows captan residues on leaves were generally higher on bottoms than tops of trees but among hedgerows, leaf residues were higher on oblique fan. The higher leaf residues resulted in 10.8% more of the captan applied per tree retained by oblique fan compared to 31.7% intercepted by the other hedgerows. Ground deposits for oblique fan and open center averaged 11.7% but were 6.3% higher for canted oblique fan and modified central leader. Ground deposits did not relate to area below trees or hedgerow type but leaf residues and that unaccounted for related to tree canopy volume. Compared to the standard open center, oblique fan was 41% more efficient at intercepting captan, modified central leader 20% more efficient and canted oblique fan showed no improvement in efficiency. Hedgerows with smaller tree canopy volumes increased captan interception, reduced spray drift and thereby provided economic and environmental gains through more efficient captan use.

Studies on the Temperature Conditions inside the Glasshouse and the Penetration of Direct Solar Radiation into Hedgerow Type Canopies

Studies on the Temperature Conditions inside the Glasshouse and the Penetration of Direct Solar Radiation into Hedgerow Type Canopies

Studies on the Canopy Photosynthesis of the Horticultural Crops in Controlled Environment

Although a great number of attempts have been made to evaluate the canopy photosynthesis, almost all of them have mainly been devoted to calculations of photosynthesis of horizontally uniform canopies such as well grown rice, maize, wheat and soybean field. Hence it seems that less information is obtained on light environment and photosynthesis of a hedgerow type canopy usually adopted for the cultivation of horticultural crops. This paper presents an approach to the light environment within hedgerow type canopies, particularly the penetration of direct sunlight into them. A silhouette method was used to obtain phytometrical data of cucumber canopies (var. Ougon) raised in a vinylhouse. The phytometrical measurements were repeated at an interval of one week during the period from April 25 to May 16 in 1973.In the calculation of penetration of direct solar radiation into the hedgerow type canopy, the cross section of the cucumber row was divided into two parts: the first part is irradiated by direct sunlight penetrated through the top surface of the canopy and the second by sunlight penetrated through the side surface of the canopy. Geometrical characteristics for the first part can be obtained by the ordinary method (Eqs. 2-4, c.f., UCHIJIMA et al., 1968).In order to assess the geometrical characteristics (effective leaf area projection function GL←, extinction coefficient of direct sunlight kd←) of the second part of the canopy, the rectangular system (x, y, z) set in parallel with the cross section of row is transformed to a new system x′=z, y′=y, z′=x by rotating only the z-axis at 90°. Extinction coefficient of direct sunlight in the second part kd← is given as a function of the angle of incidence of solar rays on the side surface of the crop rows, which is defined by both the sun and row directions. Numerical experiments are made to determine the dependence of the extinction coefficient kd← on the directions of the sun and row. Results obtained are summarized as follows:(1) A following simple relation was obtained between the leaf area of cucumber crop A and the product of leaf length l (from joint of leaf-stalk to leaf-tip) and leaf width w, and used to determine non-destructively the canopy structure of cucumber crop:A=0.937(l⋅w)-9. (cm2)(2) Inclination angle of cucumber leaves increases with the depth of the crop layer, viz., with leaf age, and the foliage inclination angle of leaves (βL) also increases with the progress of plant stages (early stage-14°, middle stage-21-24°). It seems that the azimuthal distribution of leaf area shows predominance in a direction perpendicular to the row direction (E45°S-W45°N)(Fig. 3).(3) The effective leaf area projection function for the whole stand GL↓ calculated from Eq. (2) increases with increasing sun altitude ho, and its dependence on ho agrees fairly well with the theoretical result for a horizontal-leaved cancopy (ROSS, 1970). The value of GL↓ changes a little with depth of the crop layer (Fig. 4).(4) Extinction coefficient kd↓ of direct solar radiation in the first part of the cucumber canopy is shown as a function of sun altitude (Fig. 8). Diurnal changes of extinction coefficient kd← calculated from the following equations for the four rows with different direction (N-S, E-W, E45°S-W45°N, E45°N-W45°S) show different features with the time of a year (Fig. 6, 7).kd(bn, i)←=soc i GL(bn, θo)←

The Vegetation of Wayside and Hedgerow

SEMI-NATURAL1 vegetation occupies a position midway between the natural and the cultivated. Probably owing to its ill-defined nature, it has often been regarded as unimportant. The communities which constitute the semi-natural include those of footpaths, cart-tracks, waste land, certain types of grassland, waysides and hedgerows. The two latter communities, with which this account deals, must become increasingly important and take their place in any survey of the vegetation of this country. The development of roads and the urbanization of the countryside increase their magnitude from year to year. Upon first thoughts it might be considered that these areas possess a vegetation which comprises a conglomeration of accidental individuals, but closer examination reveals definite types of communities and orderly arrangement into zones. Among the few observations on the above phenomena those of Clements (1920) may be mentioned. He describes the vigorous growth of Agropyrum glaucum as an indicator of disturbance on the roads through the sage brush on the Red Desert of Wyoming. He refers again, under the heading of Construction Indicators, to the fact that disturbance will alter the vegetation of a locality, and also, in a much earlier work (1897), to the peculiar zonation of species at roadsides on the Great Plains.