The effect of ground cover plants in apple orchards on soil-dwelling Collembola

The long-term influence of several living mulches on apple tree growth, nutrient status, yield, and fruit quality concerning the year of cover crop sowing in tree rows was evaluated in the Lower Silesia region in the southwestern part of Poland. The estimation was conducted in six apple tree ‘Ligol’ populations differentiated by the rootstock: M.26, M.9, P 60, P 2, P 16, and P 22. In experiment no. 1, one-year-old nursery stock was planted, and perennial living mulches were sown: colonial bent grass (Agrostis vulgaris With.) and white clover (Trifolium repens L.) in the same year and blue fescue (Festuca ovina L.) in the following year. In experiment no. 2, which involved two-year-old stock, the sowing of blue fescue was delayed until the second, third, fourth, and fifth years following orchard planting. The presence of the cover crop significantly affected young tree growth when one-year-old trees were planted. The sowing of the living mulch in the first or the second year after tree planting led to a significant reduction in the cumulative yield obtained from the young trees. The living mulch improved the red coloration of the fruit skin in the young orchard, but it caused a reduction in the mean fruit weight and size. However, it also contributed to decreased nitrogen concentration in the leaves of the apple trees, and the tree tolerance to living mulch increased as the orchard aged. A choice of semidwarf rootstock, postponed sowing of cover crop, and high-quality nursery stock were recognized as the most important factors for fostering apple tree tolerance to living mulches in tree rows.

Non-host plants that are intercropped with crops can either repel or attract pests, and in some cases achieve pest management. Three aromatic plant species, ageratum (Ageratum houstonianum L.; Asterales: Asteraceae), French marigold (Tagetes patula L.; Asterales: Asteraceae) and summer savory (Satureja hortensis L.; Lamiales: Lamiaceae), were intercropped in ratios of 1:1 or 1:1:1 in an organic apple orchard to investigate the community characteristics and dynamic changes in densities of the Tortricidae species Adoxophyes orana Fisher, Spilonota lechriaspis Meyrick and Acleris fimbriana Thunberg and their natural enemies in 3 vertical strata of the orchard. Intercropping aromatic plants in the orchard increased the densities of natural enemies belonging to the Trichogrammatidae, Ichneumonidae and Braconidae and reduced the rates of increase and the densities of the tortricid species relative to the control. A correlation analysis of the densities of pest species and the densities of parasitoids indicated that the reduction in some tortricid species was related to the densities of certain natural enemy species. We concluded that intercropping with aromatic plants in apple orchards can increase the biological control of tortricid pests.

Many studies have supported the enemies hypothesis, which suggests that natural enemies are more efficient at controlling arthropod pests in polyculture than in monoculture agro-ecosystems. However, we do not yet have evidence as to whether this hypothesis holds true in peach orchards over several geographic locations. In the two different geographic areas in eastern China (Xinchang a town in the Shanghai municipality, and Hudai, a town in Jiangsu Province) during a continuous three-year (2010–2012) investigation, we sampled arthropod pests and predators in Trifolium repens L. and in tree canopies of peach orchards with and without the ground cover plant T. repens. No significant differences were found in the abundances of the main groups of arthropod pests and predators in T. repens between Hudai and Xinchang. The abundance, richness, Simpson's index, Shannon-Wiener index, and Pielou evenness index of canopy predators in ground cover areas increased by 85.5, 27.5, 3.5, 16.7, and 7.9% in Xinchang, and by 87.0, 27.6, 3.5, 17.0 and 8.0% in Hudai compared to those in the controls, respectively. The average abundance of Lepidoptera, Coleoptera, Homoptera, true bugs and Acarina canopy pests in ground cover areas decreased by 9.2, 10.2, 17.2, 19.5 and 14.1% in Xinchang, and decreased by 9.5, 8.2, 16.8, 20.1 and 16.6% in Hudai compared to that in control areas, respectively. Our study also found a higher density of arthropod species resources in T. repens, as some omnivorous pests and predators residing in T. repens could move between the ground cover and the orchard canopy. In conclusion, ground cover in peach orchards supported the enemies hypothesis, as indicated by the fact that ground cover T. repens promoted the abundance and diversity of predators and reduced the number of arthropod pests in tree canopies in both geographical areas.

The quantity and quality of fruit in 2 adjacent apple orchards in eastern West Virginia were compared between 1 conventionally managed orchard and 1 with ground cover plantings underneath apple trees and reduced insecticide applications. Four species of plants [dill, Anethum graveolens L.; buckwheat, Fagopyrum esculentum Moench; dwarf sorghum, Sorghum bicolor (L.) Moench; and rape, Brassica napus L.] were planted in alternating, single-species strips under the tree canopy, and only 1 broad-spectrum insecticide (phosmet) plus Bacillus thuringiensis was applied in the ground cover orchard over the 2-yr period (1995–1996) of the study. The conventional orchard received 5 applications of an organo-phosphate each year. Disease management was the same for both orchards. The ground cover orchard had significantly greater populations of spirea aphid (Aphis spiraecola Patch) and leafhoppers [Typhlocyba pomaria McAtee, Edwarsiana rosae (L.), and Emposaca fabae (Harris) ] than the conventional orchard. The conventional orchard had more damage from fire blight than the ground cover orchard. Total yield of apples from the ground cover orchard was significantly less than in the conventional orchard, probably because of competition by the ground cover plants for water and nutrients. Fruit quality was lower in the ground cover orchard in 1995 (76% undamaged fruit compared with 80% undamaged in the conventional orchard), but in 1996 there was no difference in fruit quality between orchards (75% undamaged fruit). Plum curculio, Conotrachelus nenuphar (Herbst), damage was significantly different between orchards, but different orchards had greater damage in each year. In 1996, fruit in the conventional orchard had more apple scab, but in the ground cover orchard fruit had higher levels of summer rots and other diseases. In this study, ground covers and reduced insecticide use were not an acceptable alternative to conventional pest management because of reduced yield. However, with better management of ground cover plantings to avoid excessive competition with the apple trees, this strategy of pest management shows promise for reducing insecticide use in apple orchards.

Altitudinal changes in the diversity of plants and animals have been well documented; however, soil animals received little attention in this context and it is unclear whether their diversity follows general altitudinal distribution patterns. Changbai Mountain is one of few well‐conserved mountain regions comprising natural ecosystems on the Eurasian continent. Here, we present a comprehensive analysis of the diversity and community composition of Collembola along ten altitudinal sites representing five vegetation types from forest to alpine tundra. Among 7834 Collembola individuals, 84 morphospecies were identified. Species richness varied marginally significant with altitude and generally followed a unimodal relationship with altitude. By contrast, the density of Collembola did not change in a consistent way with altitude. Collembola communities changed gradually with altitude, with local habitat‐related factors (soil and litter carbon‐to‐nitrogen ratio, litter carbon content, and soil pH) and climatic variables (precipitation seasonality) identified as major drivers of changes in Collembola community composition. Notably, local habitat‐related factors explained more variation in Collembola assemblages than climatic variables. The results suggest that local habitat‐related factors including precipitation and temperature are the main drivers of changes in Collembola communities with altitude. Specifically, soil and litter carbon‐to‐nitrogen ratio correlated positively with Collembola communities at high altitudes, whereas soil pH correlated positively at low altitudes. This documents that altitudinal gradients provide unique opportunities for identifying factors driving the community composition of not only above‐ but also belowground invertebrates.

This study was carried out in three quarry sites at Mount Korok, also known as Jebel Kujur area, which is located within Juba Town Council in Central Equatoria State, South Sudan. The main aim was to assess the impact of quarrying activities on the local ground cover vegetation, mainly grasses and low-lying non-woody herbaceous plants. The methods used included, besides direct observations, iron frame quadrats of 1 × 1 m2 in size, for random sampling of attributes and community characteristics of the plants in three different sites. The first site was an old, abandoned stone-quarrying site; the second was where quarrying work was actively going on at the time of the study; and the third was an area never before exposed to stone quarrying (hence, acting as a control). Data were analyzed using descriptive statistics such as frequency distribution, density measures, diversity indices, and correlations. The research was carried out during the wet season when most plants were green and at different stages of flowering and/or fruiting from July through September, 2020. The results revealed that over 44 species of ground cover plants were identified, some of which were more abundant and had the widest distribution and frequency in the three study sites, including Cynodon lemfuensis, Cyperus rotundus, Bracharia ramose, Merremia pinata, Cyanodon dactylon, and Digitaria fernatad, whereas others were limited to one site or the other. Results also indicated that though stone-quarrying activities have impacts on ground cover plants, however, they are not the only factor affecting ground cover plants. More than 80% of the impacts on ground cover plants are caused by factors other than stone quarrying but were not identified during this study. It was therefore recommended that future studies in the area on the same theme should isolate the effects of stone quarrying on ground cover plants from these other operating factors through discriminant functional analysis.

Seven citrus orchards on reduced- to no-pesticide spray programs in central and south central Florida were sampled for non-phytoseiid mesostigmatid mites. Inner and outer canopy leaves, fruits, twigs and trunk scrapings were sampled monthly between August 1994 and January 1996. Open flowers were sampled in March from five of the sites. A total of 431 samples from one or more of 82 vine or ground cover plants were sampled monthly in five of the seven orchards. Two of the seven orchards (Mixon I and II) were on full herbicide programs and vines and ground cover plants were absent. A total of 2,655 mites (26 species) within the families: Ascidae, Blattisociidae, Laelapidae, Macrochelidae, Melicharidae, Pachylaelapidae and Parasitidae were identified. A total of 685 mites in the genus Asca (nine species: family Ascidae) were collected from within tree samples, 79 from vine or ground cover plants. Six species of Blattisociidae were collected: Aceodromus convolvuli, Blattisocius dentriticus, B. keegani, Cheiroseius sp. near jamaicensis, Lasioseius athiashenriotae and L. dentatus. A total of 485 Blattisociidae were collected from within tree samples compared with 167 from vine or ground cover plants. Low numbers of Laelapidae and Macrochelidae were collected from within tree samples. One Zygoseius furciger (Pachylaelapidae) was collected from Eleusine indica. Four species of Melicharidae were identified from 34 mites collected from within tree samples and 1,190 from vine or ground cover plants: Proctolaelaps lobatus was the most abundant species with 1,177 specimens collected from seven ground cover plants. One Phorytocarpais fimetorum (Parasitidae) was collected from inner leaves and four from twigs. Species of Ascidae, Blattisociidae, Melicharidae, Laelapidae and Pachylaelapidae were collected from 31 of the 82 vine or ground cover plants sampled, representing only a small fraction of the total number of Phytoseiidae collected from the same plants. Including the collection records of Martin Muma prior to 1975, a total of 69 species of Ascidae, Blattisociidae, Laelapidae, Macrochelidae, Melicharidae, Pachylaelapidae and Parasitidae have now been reported from citrus in Florida.

Influence of citrus orchard ground cover plants on arthropod communities in China: A review

The results of three-year studies on Collembola communities in spruce-fir forests along the gradient of pollution with emissions from the Middle Ural Copper Smelter (Revda, Sverdlovsk oblast) are presented. They show that the species and ecological structure of these communities change abruptly in the impact zone (1 km from the source of emissions), compared to the background zone (30 km from the source), which involves a decrease in the abundance and diversity of Collembola. Their total abundance and species richness in the zone of intermediate disturbance (7 and 4 km) are considerably higher than in the background zone, and the species structure of communities is characterized by superdominance. Four species groups differing in sensitivity to pollution are distinguished. Preference for zones with different pollution levels in closely related species is regarded as a case of ecological vicariation.

Seven citrus orchards on reduced- to no-pesticide spray programs were sampled for predacious mites in the family Phytoseiidae (Acari: Mesostigmata) in central and south central Florida. Inner and outer canopy leaves, open flowers, fruit, twigs, and trunk scrapings were sampled monthly between September 1994 and January 1996. Vines and ground cover plants were sampled monthly between September 1994 and January 1996 in five of these orchards. The two remaining orchards were on full herbicide programs and ground cover plants were absent. Thirty-three species of phytoseiid mites were identified from 35,405 specimens collected within citrus tree canopies within the seven citrus orchards, and 8,779 specimens from vines and ground cover plants within five of the seven orchards. The six most abundant phytoseiid species found within citrus tree canopies were: Euseius mesembrinus (Dean) (20,948), Typhlodromalus peregrinus (Muma) (8,628), Iphiseiodes quadripilis (Banks) (2,632), Typhlodromips dentilis (De Leon) (592), Typhlodromina subtropica Muma and Denmark (519), and Galendromus helveolus (Chant) (315). The six most abundant species found on vines or ground cover plants were: T.peregrinus (6,608), E. mesembrinus (788), T. dentilis (451), I. quadripilis (203), T.subtropica (90), and Proprioseiopsis asetus (Chant) (48). The remaining phytoseiids included: Amblyseius aerialis (Muma), A. herbicolus (Chant), A. largoensis (Chant), A. multidentatus (Chant), A. sp. near multidentatus, A. obtusus (Koch), Chelaseius vicinus (Muma), Euseius hibisci Chant, Galendromus gratus (Chant), Metaseiulus mcgregori (Chant), Neoseiulus mumai (Denmark), N. vagus (Denmark), Phytoscutus sexpilis (Muma), Phytoseiulus macropilis (Banks), Proprioseiopsis detritus (Muma), P. dorsatus (Muma), P. macrosetae (Banks), P. rotundus (Muma), P. solens (DeLeon), Typhlodromips deleoni (Muma), T. dillus (De Leon), T. dimidiatus (De Leon), T. mastus Denmark and Muma, T.simplicissimus (De Leon), and T. sp. near tunus, and Typhlodromus transvaalensis (Nesbitt). Eighty-two ground cover plants or vines were sampled within the five orchards and one or more phytoseiids were collected from 71 of these plants. Five ground cover plants with the highest numbers of phytoseiids included: Bidens alba (L.) DC (1,420 mites within 13 species), Solanum americanum L. (1,355 mites within 8 species), Amaranthus spinosus L. (1,137 mites within 11 species), Gnaphalium pensylvanicum Willd. (844 mites within 8 species) and Richardia brasiliensis (Meg.) Gomez (354 mites within 8 species).

Spoil tip production is one of the most extreme means of soil destruction, replacing the native soil with a coarse substrate. In this paper, we aim to determine the colonization of soil biota in new substrates, using collembola assemblages as an indicator. In Northern France, we sampled collembola communities in 11 coal mine spoil tips and their surroundings divided in four stages of vegetation development: bare soil, meadow, shrub and tree covers. We demonstrated that collembola assemblages of spoil tips were different from those observed in the surrounding native soil. Collembola communities on bare soil were characterized by pioneer (based on the Indval index) or exotic species (new in Northern France). However, homogenization occurred with development of vegetation cover. Indeed, our data showed no difference in springtail diversity between spoil tips and their corresponding environments regarding the tree vegetation cover. Using the Indval method, we defined pioneer, colonizing, opportunist or stenoecious species as a function of substrate affinities. Using the same method, we defined specialists, elective, preferring or indifferent species as a function of vegetation cover affinities, showing similarities with previously published surveys. Hence, our results were obtained by a focused analysis of species and their particularity. Finally, we discussed the interest in and the complementarity between the species analysis approach and the methodology dealing with functional traits and of its importance in the decision process of restoration and/or conservation of nature.

Abstract. Satriawan H, Fuady Z, Ernawita. 2021. The potential of Nephrolepis biserrata fern as ground cover vegetation in oil palm plantation. Biodiversitas 22: 4808-4817. Nuisance plants or weeds are commonly found in agricultural landscapes including in oil palm plantations. Despite being considered as weeds, several of them have the potential to be used as ground cover vegetation including Nephrolepis biserrata (Sw). Schott. This fern species exhibits beneficial characteristic as ground cover plant especially in terms of the contribution of organic matter and soil moisture through the prevention of evapotranspiration. The objective of this research is to explore the potential of N.biserrata as ground cover vegetation in oil palm plantations based on the assessment of its ecological characteristics regarding the growth and decomposition rate, tolerance to shade, organic contents and carbon accumulation. The split plot experimental design was used with the age of oil palm plants was used as main plot while in the sub-plots the spacing of N. biserrata was used at three varying distances 10x10cm, 20x20 cm, and 30x30 cm, each treatment had three replicates. Nine parameters observed were the percentage of growth, the percentage of ground cover, plant height, fronds number per plant, leaves number per plant, Leaf Area Index, dry weight (g), nutrient content in plant tissue, and potential carbon stock. Results showed that N. biserrata showed rapid growth in covering the ground surface (8-12 weeks after planting), had rapid decomposition rate (30-60 days), tolerant to shading which was characterized by the highest percentage of growth up to 81.16% and covering area up to 95.9%, accumulated organic contents of N (1.23-1.53%), P (0.18-0.22%), and K (1.4-1.67%), respectively. In addition, total dry weight biomass obtained was 27.1 ton/ha, accumulated carbon in plant of 0.9 tons C/ha/year, and amount of soil carbon stock 76.4-97.4 tonnes/ha/year. The results of this study suggest that Nephrolepis biserrata is a potential plant to be utilized as a ground cover plant in oil palm plantations.

Boon Pring is one of the ecotourism destinations in Malang regency with tourism attractions including motor boats, water bikes, and picnic activities. These activities can cause environmental degradation in Boon Pring area. The purpose of this research is to analyze taxa richness of ground cover plant, diversity, and community structure of herpetofauna in Boon Pring and explain the environmental quality in Boon Pring based on their relationship. The method used is selective purposive belt transect with 10 m long belt and 10x5 m 2 plot area. Each station is repeated four times. The data obtained were analyzed with Ms. Excel and the PAST program to search Taxa Richness for plants, abundance, frequency, Shannon – Wiener diversity index and Import Value Index (IVI) for Herpetofauna. Then they were analyzed regression, cluster, and biplot to determine the relationship between the two. The results showed decreased of ground cover plants taxa richness and herpetofauna diversity index from station one to station four. The value of IVI indicates the dominance of Eutrophis multifasciuata species in degraded sites. Determination coefficient showed a value of 51%, which means there is a positive relationship between ground cover plant and herpetofauna diversity. The conclusions of this study, the taxa richness of ground cover and diversity of herpetofauna have decreased in areas with degraded environmental quality. There is a dominance of one type of herpetofauna in the degraded areas of Eutrophis multifasciuata . Between the taxa richness of ground cover plants and diversity of herpetofauna showed a positive relationship, in this study 51%. Keywords : Boon Pring, Diversity Index, Ground Cover Plant, Herpetofauna, Regression.

Soils are among the most biodiverse systems on earth. The coexistence in soils of a multitude of animal species has long puzzled soil ecologists. How can so many species co-occur, and what are the processes driving and maintaining species coexistence in soil? Using a deductive approach, I propose that (1) there are assembly processes, (2) that work on, or are related to, certain objects, i.e., functional traits, to (3) produce particular patterns. I use a conceptual model combining patterns of evolution of species traits, trait similarity and phylogenetic relatedness between coexisting species, from which to infer assembly processes in soil Collembola (springtail) communities collected from habitats characterized by different disturbance regimes. In Chapter 2, I reconstruct a Collembola phylogeny and use phylogenetic comparative methods to explore phylogenetic signal, model of evolution and ancestral state for a variety of traits, including body shape, body length, pigmentation, number of ommatidia, vertical stratification and reproductive mode. The results demonstrate that body shape of Collembola evolved quickly early in their diversification but slowed down afterwards. In contrast, evolutionary transitions in pigmentation, number of ommatidia and reproductive mode depended on how deep in the soil that species live. Ancestral Collembola traits were likely slender body, hemiedaphic way of life, sexual reproduction, possession of many ommatidia and bright color, but these traits presumably changed several times during species diversification. The phylogenetic signal detected in these traits forms the basis of further community phylogenetic analyses. In Chapter 3, I propose the neutral lipid fatty acid composition of Collembola as a functional trait related to both food resources and physiological functions and test phylogenetic signal in fatty acid profiles. Long-chain polyunsaturated fatty acids related to physiological functions demonstrated phylogenetic signal. In contrast, most food resource biomarker fatty acids and the ratios between bacterial, fungal and plant biomarker fatty acids exhibited no phylogenetic signal. These results suggest that Collembola with close phylogenetic affinity experienced similar environments during divergence, while niche partitioning in food resources among closely related species favored species coexistence. In Chapter 4, I use both community phylogenetic and trait-based approaches to infer the assembly processes of Collembola communities inhabiting arable fields, grasslands and forests. The results indicate that Collembola communities in arable fields were mainly structured by environmental filtering, while niche partitioning dominated in forests. Epedaphic (surface-living) species showed phylogenetic clustering in grasslands and forests, while in forests they also possessed similar traits. Hemiedaphic (sub-surface-dwelling) species were phylogenetically clustered in arable fields and grasslands, but in forests they were phylogenetically overdispersed and had different traits. However, the assembly of euedaphic (soil-dwelling) communities did not differ from random patterns. Furthermore, different phylogenetic groups of Collembola showed different patterns in the three habitats. These results suggest that Collembola assemblages are driven by different mechanisms in different habitats, with the relative importance of these mechanisms different between soil strata and between phylogenetic lineages. Furthermore, applying community phylogenetic approaches to a manipulative soil block experiment (Auclerc et al. 2009; Soil Biology and Biochemistry 41, 1596–1604) in Chapter 5 shows that Collembola community composition during their succession in forest and meadow soil was determined by the interaction of dispersal and selection processes. Niche partitioning gradually strengthened at later successional stages, offsetting the effects of environmental filtering. As a consequence of dispersal, community composition changed gradually from that resembling the original habitats to that of the new habitats. In the final chapter I ascribe the above-mentioned patterns to the scenarios presented in the conceptual model and discuss the likely mechanisms, with reference to the four high-level processes, selection, dispersal, drift and speciation, proposed in The Theory of Ecological Communities (Vellend 2016). I provide a roadmap for integrating phylogenetic comparative methods, community phylogenetic analyses and trait-based approaches in studies on the assembly processes of soil communities. Overall, this thesis is the first application of new methods developed in community ecology and evolutionary biology to the study on assembly processes in the soil communities. Future studies using the conceptual model and roadmap proposed in this thesis will advance our understanding of the mechanisms driving and maintaining soil biodiversity from both ecological and evolutionary perspectives.

Seven citrus orchards on reduced- to no-pesticide spray programs were sampled for predacious mites in the families Eupalopsellidae and Stigmaeidae (Acari: Prostigmata) in central and south central Florida. Inner and outer canopy leaves, fruit, twigs, and trunk scrapings were sampled monthly between August 1994 and January 1996. Open flowers were sampled in March from five of the sites. Two species of eupalopsellid mites (Exothorhis caudata Summers and Saniosulus harteni (van-Dis and Ueckermann)) were identified from 252 specimens collected within citrus tree canopies within the seven citrus orchards of which 249 were E.caudata. Only two E. caudata were collected from ground cover plants within five of the seven orchards. Eight species of Stigmaeidae were identified from 5,637 specimens: Agistemus floridanus Gonzalez, A. terminalis Gonzalez, Eustigmaeus arcuata (Chandhri), E. sp. near arcuata, E. segnis (Koch), Mediostigmaeus citri (Rakha and McCoy), Stigmaeus seminudus Wood, and Zetzellia languida Gonzalez were collected from within citrus tree canopies from seven orchard sites. Agistemus floridanus was the only species in either family that was abundant with 5,483 collected from within citrus tree canopies compared with only 39 from vine or ground cover plants. A total of 431 samples from one or more of 82 vines and ground cover plants were sampled monthly between September 1994 and January 1996 in five of these orchards and one or more eupalopsellids or stigmaeids were collected from 19 of these plants. Richardia brasiliensis (Meg.) Gomez had nine A. floridanus from 5 of 25 samples collected from this plant. Solanum sp. had five A. floridanus from three samples taken. Both eupalopsellid and stigmaeid species numbers represented <1% of the total numbers of phytoseiid species taken from the same plants. The two remaining orchards were on full herbicide programs and ground cover plants were absent. Agistemus floridanus was more abundant in the citrus orchards with on-going or recent herbicide programs compared with orchards having well-developed ground cover plants. Agistemus floridanus was most abundant on inner leaves between January and April and again during September through November. Additional collection records of E. caudata, S. harteni, A. terminalis, M. citri, Z. languida, and Zetzellia sp. near silvicola within Florida citrus orchards between 1989 and 2004 are included. Four species of Eupalopsellidae and ten species of Stigmaeidae occur within Florida citrus orchards.