Margin Strips Research Articles

Dynamics of Land Use and Coverage and its Impacts on the Upper Moquegua River Hydrographic Basin

Objective: Evaluate; identify and qualify the impacts of the dynamics of land use and coverage in the years 1973 and 2016 in the Hydrographic Basin and in the marginal strip of the Upper Moquegua River in Moquegua Peru. Theoretical framework: In the area studied, human activities and global climate change have disturbed the balance of natural systems, causing major impacts and complex consequences on land use and cover. Method: Digital image processing techniques and supervised classification using the maximum likelihood method were used, followed by matrix editing with refinement of the base and thematic cartography, reaching 94.4% accuracy in interpretation for the year 2016. Result and discussion: The main changes identified regarding the dynamics of land use and coverage were similar in the basin area and in the marginal strip. An increase was noted in the urban area of the entire basin of 568.53ha (1,097.96%) and 134.86ha (1,263.33%) in the marginal strip, which may have been largely influenced by mining activity, which was not observed in 1973, but present in 2016, occupying an area of 1,092.77ha throughout the basin, with 171.99ha in the marginal strip. The areas that had the greatest reduction were those of the glacier, with 2,275.39ha (-93.33%) in the entire basin and 83.77ha (-100.00%) in the marginal strip. Conclusion: With the results of this research, we hope to contribute to the literature related to the topic and to actions and public policies that encourage the appropriate use of land in the Upper Moquegua River Basin, especially in environmental protection areas.

THE DIVERSITY OF USEFUL ARTHROPODS IN TWO WHEAT AGROECOSYSTEMS FROM TRANSYLVANIAN PLAIN

The increase in agricultural production is conditioned by several factors, among which plant protection against pests plays a very important role. Alongside chemical methods, biological control methods against harmful organisms in crops have recently become widespread, and one of these methods is the use of useful insects (predators and parasites). Therefore, during 2016-2018, a study was conducted on monitoring the useful entomofauna in the culture of autumn wheat, in two types of agroecosystems, at Turda and Bolduț, within the Turda Research and Development Station for Agriculture. The two locations are quite close in terms of distance, but very different in terms of territorial organization, with the Bolduț farm being surrounded by a network of agroforestry shelterbelts. In Turda, the plots are located in open field conditions and are protected by rare spontaneous marginal strips. The research aimed to evaluate the diversity of useful arthropod fauna in the two agrobiocenoses, as well as the influence of the agroecosystem on these insects. Following the observations, it can be stated that the entomophagous arthropods identified in the two agroecosystems differ only in terms of ecological indicators, belonging to the same groups of entomophages, their diversity being closely related to climatic conditions, applied technology, but also to the type of agroecosystem.

Investigating Earthquake-Induced Changes in the Persian Gulf Marginal Strip, Using Sentinel-1A Images and Radar Interferometry

Geohazards, such as earthquakes, pose significant threats to human life and infrastructure in various regions across the globe. Iran, in particular, is highly vulnerable to earthquakes due to its unique structural and tectonic characteristics. Therefore, it is crucial to monitor geohazards in order to mitigate their impacts. Several techniques, including the global positioning system, geodesy, tacheometry, and mapping cameras, have been developed for this purpose. Among these methods, radar interferometry has emerged as a particularly accurate and cost-effective approach. It is capable of operating under all weather conditions, 24 h a day, and can cover large areas with high spatial and temporal resolution. In this research, we employed Sentinel 1A images and radar interferometry to investigate the changes in the Earth’s surface following earthquakes in the marginal strip of the Persian Gulf. Specifically, our focus was on earthquakes in Bandar Khamir, and we analyzed the Earth’s surface changes three days and fifteen days after the events. The findings of our study revealed that the most significant uplift occurred around Bandar Khamir, with an uplift rate of 14 cm. Conversely, the highest subsidence was observed near Bandar Charak, with a subsidence of 12 cm. Furthermore, we observed a rise of 32 cm around the eastern and northern regions of Bandar Khamir 11 days after the initial period, accompanied by a subsidence of 31 cm around Bandar Lange and Bandar Charak. These results underscore the importance of continuous monitoring of earthquakes and their impact on the Earth’s surface, particularly in coastal areas where the effects on the water table and coastal infrastructure can be severe. In conclusion, this study highlights the significance of employing radar interferometry as a powerful tool for monitoring and assessing the impacts of earthquakes.

Quantifying trade‐offs between butterfly abundance and movement in the management of agricultural set‐aside strips

Abstract Agri‐environment schemes (AES) create small areas of habitat within agricultural landscapes to support biodiversity. Here, we study butterfly flight behaviour within linear AES features and examine whether differences in resource availability affect the speed, linearity, or directionality of local movements, thereby affecting their contribution to landscape connectivity. We surveyed butterflies within three basic (naturally regenerating) and three wildflower‐sown linear field margin strips (0.09–0.15 ha) on a farm in North Yorkshire, UK, and mapped butterfly flight paths to quantify local displacement (movement speed), efficiency (linearity, turning angles), directionality (step orientation), and behaviour (time spent flying, nectaring). Butterfly species richness was similar between margin types {estimated asymptotic species richness of 21.9 [confidence interval (CI): 15.0–77.7] for basic margins and 14.2 (CI: 14.0–18.7) for wildflower‐sown margins}, but abundance was 78% higher in wildflower‐sown margins. For the three most common species [meadow brown, Maniola jurtina (L.); ringlet, Aphantopus hyperantus (L.); and small white, Pieris rapae (L.); n = 233 paths], movements within both margin types were highly linear (median turning angle 45°) and generally oriented along the length of the margin strip (median step orientation 27°). Movements in basic margins were slightly more orientated along the length of the margin but we found no differences between margin types in speed, path linearity, turning angles or the proportion of time spent flying or nectaring. We found strong channelling of movements along field margin strips regardless of management type, potentially aiding landscape connectivity. Providing field margin strips with additional foraging resources through wildflower‐sowing increases butterfly abundance without impeding local movement rates or efficiency.

Assessment of the spatial distribution of the sunflower tumbling beetle population

We have evaluated the distribution of the sunflower tumbling beetle (STB) to optimize the methods of its monitoring and to establish the spatial localization of the phytophage concentration in order to increase the efficiency of measures to regulate its abundance. We counted the STB after harvest at least in 20 points of the field; we collected stems and their root parts in plots 1x1 m, opened them and counted the number of larvae in each stem; we also counted broken plants at a height of 50-60 cm. Svedberg and Lloyd models used to analyze the distribution (uniform, random, contagious) of the STB population on the crops of F1 hybrid "Sonyachny Nastriy". The data obtained as a result of solid - by field squares (grid) and W-like route surveys processed according to their parameters. The last ones was process both with application of statistical correction of plots according to the number of the STB (larvae / plant) - by changing the index of abundance by the size of an accounting plot, which is different from the average area, and by results of direct counts carried out in one or another point of the field. The distribution can be spatial - within the entire agrocenosis, and linear - within the vector (strip of registration plots). It can also be based on complete (grid data) or incomplete (en-route counts) information. Lloyd's model assumes a higher probability of random values of distribution. When estimating the distribution based on incomplete information, the values of the Swedberg and Lloyd coefficients for the spatial distribution are 1.708 and 1.604 for W-route with area-adjusted abundance and 1.692 and 1.596 without adjustment respectively, which gives values of contagious and random distribution. Applying the linear version of the estimate gives a contagious distribution for the Swedberg and Lloyd models for the 1st vector and an even distribution for the 2nd and 3rd vectors. When estimating the distribution based on complete information (the "grid" variant), the spatial distribution of Lloyd - 0.657 and Swedberg - 0.957 is uniform, but for the latter it is very close to the random distribution. The linear distribution by Swedberg varies from contagious - 1.287 to uniform - 0.916 and 0.447, and by Lloyd - from random - 1.237 to uniform - 0.499 and 0.014. Given incomplete information, the polynomial trends allow us to determine the magnitude of the uncertainty in the distribution as the geometric distance between the points of intersection of the trend lines with the 45o optimization line and the Swedberg contagion and Lloyd's randomness levels. Provided the information is complete, linear trends allow us to determine the magnitude of the uncertainty in the distribution as the geometric distance between the points of intersection of the trend lines with the Swedberg-Lloyd uniformity levels. "Grid" of these counts allows revealing marginal effects in spatial distribution of phytophage population, the number of which is maximal in the marginal strip bordering the forest belt, and minimal in the center of agrocenosis. Under the condition of incomplete information it was found that according to Swedberg criterion the spatial distribution of the STB is contagious and Lloyd's is random, the linear distribution for both models changes from contagious to uniform; under the condition of full information it is found that on the basis of Swedberg-Lloyd models the spatial distribution of the stonefly is uniform, linear distribution for the Swedberg model changes from contagious to uniform, Lloyd - from random to uniform; estimation of the spatial distribution of the population on the basis of full information is the most optimal because it allows to determine the marginal effects.

Determinación de la faja marginal del rio Caplina en el distrito de Pachia y Calana mediante modelamiento hidráulico

En el departamento de Tacna específicamente los Distritos de Pachía y Calana presentan vulnerabilidad a inundación por máximas avenidas, según las evaluaciones realizadas por la Autoridad Nacional del Agua, en los años del 2001 y 2019 según el registro de datos hidrométricos de la Estación Calientes, se reportaron caudales de 33 m3/s y 26 m3/s respectivamente ocasionando destrucción de las bocatomas de Challata y Calientes, inundación de áreas agrícolas, dejando en aniego la zona de los Baños termales en Calientes, colmatación de las obras de encauzamiento del rio Caplina desde Calana hasta el sector Piedra Blanca. La determinación de una faja marginal mediante un modelamiento hidráulico busca salvaguardar la vida de los habitantes y también los aspectos económicos y ambientales

Use and occupation of soil and carcinoculture in the ciliar forest of the Paraíba do Norte river in municipality of Mogeiro/PB, Brazil

The environmental collapse has required an enormous effort to guarantee studies that contribute to planetary environmental conservation. Diametrically, the riparian forest has suffered a great loss of vegetation biome to the detriment of human occupation in these ecosystems. Currently, in the face of the global environmental crisis, riparian forests have been the most degraded ecosystem on the planet. In another sense, riparian forests play an indispensable role in maintaining aquatic and terrestrial environments. Work aims to map the uses and occupations of the soil in riparian forest areas of the Paraíba do Norte River, in Mogeiro - PB. To this end, the research methodology consists of characterizing the use and occupation using remote sensing and delimitation of images to create marginal strips of the 50-meter perennial natural water course in line with the Forest Code (12651/12).

Analysis of the crustal structure of São Francisco Craton and their marginal strip based on GDS and gravity data

Geomagnetic Depth Sounding (GDS) is a natural source electromagnetic method used to investigate great depths of the Earth's interior to obtain the electrical conductivity distribution. GDS data from nineteen stations distributed in the São Francisco Craton (SFC) and its marginal strips have been processed and analyzed. The processing of the GDS data employed consolidated techniques such as contour maps of the Fourier transform, horizontal polarization ellipse, data stacks in time-domain and frequency-domain, as well as the implementation of electromagnetic modeling based on line source of current. To assist the interpretation of the GDS, Bouguer and geological maps of the tectonic compartments of the SFC have been employed. In addition to those mentioned, inverse gravimetric modeling has been implemented for the Moho depth based on the Parker-Oldenburg methodology. The joint analysis of GDS and gravimetric data and the geological model allowed to design conductive blocks in the crust along with the investigated profile ensured by the development of an innovative approach to electromagnetic modeling GDS.

Conflitos do uso de solo em áreas de preservação permanente em Candelária (RS)

The urbanization process of Brazilian cities has generated several environmental problems, including occupations and irregular uses in Permanent Preservation Areas (PPA). Land use in marginal strips, coupled with vegetation removal, causes environmental degradation, causing instability of ecosystems. For this reason, the present study aims to identify and analyze land use and land occupation conflicts in PPA localized in the urban perimeter of the municipality of Candelária, Rio Grande do Sul, Brazil. The methodology uses geographic and statistical data from the Brazilian Institute of Geography and Statistics (IBGE) and spactial bases provided by the municipal government. Data systematization and maps elaboration were performed in Geographic Information System (GIS) platform. Candelária presents streams that cut the urban mesh and flow into the Pardo River, thus, there are PPAs of considerable size within the urban area. Research shows that there are improper uses in PPA, such as buildings, irregular settlements and agricultural crops. Finally, the results indicate there is significant area under protection in the city being impacted by human action, aggravating the reduction of native forest.

Sowing of margin strips rich in floral resources improves herbivore control in adjacent crop fields

Field margin vegetation provides resources for natural enemies of crop herbivores. Thus, the design of plant mixtures improving resource provisioning is being discussed increasingly with respect to improving herbivore control. We set up a field experiment to assess the effect of (i) a wildflower strip optimized for nectar provisioning; (ii) a grass strip and (iii) spontaneous vegetation on herbivore regulation in oilseed rape and wheat. We also analyzed the attractiveness of plant species to natural enemies. The cover of flowering entomophilous plant species as a proxy of floral resource provisioning was twice as high in wildflower strips compared with the other strip treatments. Natural enemy densities were higher within and close to wildflower strips in the field. A corresponding effect on aphid predation and aphid infestation was observed. Significant negative correlations between natural enemy abundance in the margin and aphid infestation in the fields supported a causal relationship. The sown wildflower strip species were more attractive to natural enemies than spontaneous vegetation. The results of the present study demonstrate that improved nectar provisioning increased the predation and parasitism of crop herbivores. Further research on the spatio‐temporal dynamics of interactions is needed to determine why not all crop herbivores respond to an increase of natural enemies in field margins.

Influence of the margin vegetation on the conservation of aphid biological control in apple orchards

The influence of three margin strip treatments (wildflower strips, grass strips and spontaneous vegetation) adjacent to apple orchards on the biological control of Dysaphis plantaginea Passerini (Hemiptera: Aphididae) was compared during two consecutive years. The wildflower strips provided the highest amount of floral resources. Within the margin strips, hoverflies responded positively to higher resource provisioning whereas ladybird abundance did not differ between strip treatments. Within the orchards, the presence of parasitoids, hoverflies, and ladybirds in aphid colonies and the predation of sentinel aphids were not significantly affected by the adjacent strip treatments. The number of natural enemies observed in aphid colonies was mainly driven by aphid number. Aphid numbers were higher close to the margin strips suggesting that aphid colonization from orchard edges may counteract the positive effect of wildflower strips on natural enemy abundance and on a reduction of aphid infestation. The results confirm the positive influence of floral resource provisioning by wildflower strips on the conservation of aphid natural enemies, but also suggest that effects of wildflower strips on aphid regulation inside orchards are not very strong compared with spontaneous vegetation naturally occurring in the margins.

Assessing non-intended effects of farming practices on field margin vegetation with a functional approach

To assess the unwanted side effects of farming practices on non-target plants, we used a nationwide survey of the vegetation of arable field margin strips. The vegetation was surveyed during two years (2013, 2014) in 430 field margins distributed over all agricultural regions of France. We used two complementary multivariate, trait-based approaches to examine how ten plant traits were related to ten environmental variables describing abiotic conditions, landscape factors, field margin management and in-field practices. Generalized additive mixed models were also developed to assess how the same environmental variables correlated with species richness, functional diversity and relative richness of agrotolerant versus hemerophobic species. Traits responded primarily to an environmental gradient of landscape diversity and field margin management. For instance, narrow field margin strips, frequent management and presence of a ditch favoured annual plants, small size at maturity and perennial plants, respectively. The second environmental gradient affecting plant traits was related to field size and intensity of in-field farming practices. On this gradient, fertilizer drift appeared to have a much stronger effect on plant trait composition of field margin strips than herbicide drift. The relationship between species richness, or functional diversity, and environment was consistent with the trait-based approach: the two former variables were negatively correlated with agriculture intensification (e.g. field size). However, this analysis also highlighted new covariates, such as a negative relationship between frequency of herbicide use and species richness. Some of the observed patterns seemed to be driven by differential responses of agrotolerant versus hemerophobic species, with the latter being more species-rich under organic than under conventional farming. Despite efforts to reduce nitrogen inputs since the 2000s, our results shows that N-fertilization still has significant non-intended effects on field margin vegetation. More generally, increasing the width of field margin strips, keeping or restoring semi-natural elements (ditches, hedges) in the field boundary, and lowering the number of management events may promote grassland plant species more typical of semi-natural habitats.

Delimitation of permanent preservation areas of Paurá Lagoon (Middle Coast of Rio Grande do Sul, Brazil) using multitemporal satellite image analysis

Permanent Preservation Areas (PPA) are determined by the Brazilian Forest Code (Federal Law nº 12.651/2012) to protect biodiversity, soil, water, and climatic integrity. Around lakes and lagoons in rural areas, the law establishes marginal strips of PPA with a minimum width of 100 m (or 50 m for lakes with less than 20 ha). Some of these water bodies may have their surface dimensions markedly changed due to seasonal variations. PPA demarcated during periods of maximum water level would present ecological advantages. However, such variations were not included as criteria for PPA around lakes and lagoons in the new 2012 Forest Code. Moreover, seasonal variations effects are not yet sufficiently known in water bodies of most regions. In this work, a methodology previously developed was used to delimitate and measure water surface area and PPA of Paurá Lagoon during maximum water overflow - due to rain water excess (WE), and water deficit - due to rain water scarcity (WS). This lagoon is situated in a coastal area ranked as conservation priority in Brazil (31°34’ S, 51°18’ W; 31°34’ S, 51°17’ W; 31°35’ S, 51°18’ W and 31°35’ S, 51°19’ W). Analyses of rainfall records covering the 1992-2012 time series, water balance and remote sensing with freely available GIS application (SPRING) were employed to select satellite images from WS and WE dates. Two Landsat-5 TM images, dated 29/04/2009 (WS) and 06/09/1998 (WE) were selected and geoprocessed to detect differences in areas under WS and WE, respectively. For lagoon surface area and PPA, 66.29 ha and 42.36 ha were calculated during WS, and 92.27 ha and 53.25 ha during WE, respectively. At maximum WE (local winter and spring), lagoon surface area was 25.98 ha larger, while PPA had an addition of 10.89 ha. Although Landsat images have spatial resolution limitations, the methodology allowed the identification of the most suitable annual period to delimitate a larger area around the water body. Following in situ demarcation, the resulting larger PPA may provide superior ecological benefits to priority conservation regions. The methodology tested may be a useful tool to integrated management of lakes and wetlands in coastal zones.

MAPEAMENTO DAS ÁREAS DE PRESERVAÇÃO PERMANENTE DO ESTADO DO ESPÍRITO SANTO, BRASIL

O estudo foi realizado em todo o estado do Espírito Santo, com o objetivo de delimitar as Áreas de Preservação Permanentes (APPs) na ótica da Lei 12.651/2012 (Código Florestal) e ressaltar a importância de identificar as áreas de forma automática. Cada APP possui uma metodologia própria para o seu mapeamento, entretanto, todas foram mapeadas com o auxílio de geotecnologia. O estado possui 22,43% de sua área de APPs, distribuídas ao longo da faixa marginal dos cursos d’água (10,42%); no entorno de lagos e lagoas naturais (0,67%); no entorno dos reservatórios d'água artificiais (0,02%); no entorno das nascentes (0,89%); em encostas com declividades superiores a 45º (0,24%); em restingas (1,92%); em manguezais (0,19%); em topo de morros (8,98%); e em altitudes superiores a 1.800 metros (0,19%) da área total do estado. O presente estudo serve como subsídio técnico para avaliação e quantificação da APPs em um Estado, visto que é o primeiro em nível estadual no Brasil sobre o tema.

Which Traits Allow Weed Species to Persist in Grass Margin Strips?

Sown-grass margin strips, historically established to limit pesticide drift and soil erosion, are now also promoted for enhancing floral diversity and associated ecosystem services. To better understand weed community assembly in grass margin strips, we performed floral surveys in 75 sown-grass margin strips in two regions in France and characterized each species using information from trait databases. We hypothesized that traits of dominant species would differ between newly sown-grass margin strips and older strips. Weed species were separated into functional groups based on their traits using multiple correspondence analysis and hierarchical ascendant classification. Functional group trajectories were investigated in sown-grass margin strips that differed in age using a space-for-time substitution approach. We found that geophyte, competitor, and monocotyledon species were more frequent and abundant in grass margin strips than therophyte, ruderal, and dicotyledon species. Results also showed that floral diversity was greatest in grass margin strips of intermediate age. Our findings have implications for optimizing diversity and ecosystem services on land enrolled in conservation programs and suggest that mowing later in the season and periodic soil disturbance can increase floral diversity. The analytical framework that we introduced in this research can also be used to explore weed community assembly in other systems.

Determination of open pit diamond mine limits with regard to stripping time difference

The analysis of methods to account for stripping time difference at the stage of determination of limits in deep open pit mining reveals advantages and shortcomings of the methods and provides a principled approach to determination of a discount ultimate strip ratio for the most representative geological and geotechnical conditions of diamond-bearing ore bodies in the form of single pipes. Discounting of marginal strip ratios is based on adding the common formula with an average mean discount coefficient represented by a correlation of mining rate decrease, stripping zone height and highwall slope angle. It is shown that target variation of the factors included in the discount marginal strip ratio allows considerable influence on depth and efficiency of open pit mining.

Nectar accessibility determines fitness, flower choice and abundance of hoverflies that provide natural pest control

Summary In modern agricultural landscapes, many organisms providing ecosystem services such as pollination and natural pest control are likely constrained by shortage of nectar and/or pollen required for adult nutrition. More and more flower‐rich field margin strips and other habitats are created to eliminate these constraints. For most target organisms, however, it is not well known which (types of) flowers are effective in providing suitable pollen and nectar. We studied the suitability of a wide range of flowers as a food source for zoophagous hoverflies (hoverflies with predatory larvae) at five different levels: nectar accessibility (based on flower morphology), realized adult fitness, flower choice (both based on cage experiments), flower visitation and hoverfly abundance in mixed vegetation (both based on field observations). Realized survival of Episyrphus balteatus is related to effective flower depth by a sigmoid function. The critical flower depth is 1·6 mm, which is less than the proboscis size of the hoverfly. For Asteraceae, the critical floret depth is even less than 1·0 mm, which – in contrast to common knowledge – rules out most species within this family. Both flower choice in the laboratory and flower visitation rates in the field are well correlated with nectar accessibility and realized adult survival. In mixed floral vegetation, the number of zoophagous hoverflies is highly correlated with the abundance of only those flowers that have accessible nectar for these hoverflies. Synthesis and applications. This comparative study demonstrates that nectar (and not pollen) accessibility is the main driver determining flower resource suitability, flower choice and abundance of zoophagous hoverflies in arable field margins. The study identifies the limited range of plant species that can effectively support these beneficial insects. Preserving the right flowers in and around agricultural fields could enhance local populations and the pest control and pollination services they provide.

장대터널의 사례에 기반한 대심도 지하도로 교통시설 및 운영 개선방안

Recently, starting with the deep underground road construction plan in Seobu Expressway, Korea, there area many studies on deep underground roads to be newly built. However, there is an extreme lack of safety standards, which does not consider traffic conditions and road driving characteristics. Therefore, this study reviewed safety elements to reflect in the deep underground road planning by analyzing driving stability of longitudinal tunnels with road environments, which resemble deep underground roads. For comprehensive analysis, the characteristics and causes of the accidents that have occurred in seven longitudinal tunnels with a length of 2km or over in Gangwon area, were collected. Specifically, geometric structures and facilities of each tunnel were investigated. Also, the present state of facility installation and the changes in driving speed of vehicles passing through each tunnel were observed to analyze the causes for the traffic accidents in each tunnel and accident reduction alternatives. It was revealed that the most frequent accidents in the tunnels resulted from the changes of traffic flow due to the abrupt speed reduction of forward vehicles, or the failure in speed control of following vehicles during the traffic congestion situation. Moreover, installing facilities such as plane and longitudinal curves, median strips and marginal strips seem to induce consistent driving speed. These results mean that for accident prevention, speed management must be preceded and there is a need to develop and introduce safety facilities actively to control the driving flow of forward and following vehicles.

Enhancing grasshopper (Orthoptera: Acrididae) communities in sown margin strips: the role of plant diversity and identity

Grasshoppers are important components of grassland invertebrate communities, particularly as nutrient recyclers and as prey for many bird species. Sown margin strips are key features of agri-environmental schemes in European agricultural landscapes and have been shown to benefit grasshoppers depending on the initial sown seed mixture. Understanding the mechanisms by which the sown mixture impacts grasshoppers in sown margin strips is the aim of our study. Here, we investigated plant–grasshopper interactions in sown margin strips and the respective effects of plant identity and diversity on grasshoppers. We surveyed plants and grasshoppers in 44 sown margin strips located in Western France which were initially established with three sowing mixtures dominated, respectively, by alfalfa, Festuca rubra and Lolium perenne and Festuca arundinacea. Grasshopper species contrasted in their response to plant diversity and to the abundance of sown and non-sown plant species. Some grasshopper species were positively correlated with the abundance of grass and especially of a single sown plant species, F. rubra. In contrast, other grasshopper species benefited from high plant diversity likely due to their high degree of polyphagy. At the community level, these contrasted responses were translated into a positive linear relationship between grass cover and grasshopper abundance and into a quadratic relationship between plant diversity and grasshopper diversity or abundance. Since plant identity and diversity are driven by the initial sown mixture, our study suggests that by optimizing the seed mixture, it is possible to manage grasshopper diversity or abundance in sown margin strips.

Upper lid crease approach for margin rotation in trachomatous cicatricial entropion without external sutures.

To describe the use of a lid crease incision for upper eyelid margin rotation in cicatricial entropion combining internal traction on the anterior lamella, tarsotomy, and tarsal overlap without external sutures. Surgical description: The main steps of the procedure consisted of exposure of the entire tarsal plate up to the eyelashes followed by tarsotomy through the conjunctiva. A double-armed 6.0 polyglactin suture was then passed through the distal tarsal fragment to the marginal section of the orbicularis oculi muscle. As the sutures were tied, the distal tarsus advanced over the marginal section, and traction was exerted on the marginal strip of the orbicularis muscle. There were no bolsters or external knots. The pretarsal skin-muscle flap was closed with a 6.0 plain gut suture. We used this procedure at a tertiary hospital in Saudi Arabia from 2013 to 2014. Sixty upper lids of 40 patients (23 women and 17 men) were operated on, with an age range of 44-99 years [mean ± standard deviation (SD) = 70.9 ± 13.01 years]. Bilateral surgery was performed on 21 patients. Follow-up ranged from 1 to 12 months (mean 3.0 ± 2.71 months). Forty percent of the patients (24 lids) had more than 3 months' follow-up. The postoperative lid margin position was good in all cases. Trichiasis (two lashes) was observed in only one patient with unilateral entropion on the medial aspect of the operated lid. The upper lid margin can be effectively rotated through a lid crease incision with internal sutures. The technique combines the main mechanisms of the Wies and Trabut approaches and avoids the use of bolsters or external sutures, which require a second consultation to be removed. Some other lid problems, such as ptosis, retraction, or dermatochalasis, can be concomitantly addressed during the procedure.