Grass, Ingo

[["dc.bibliographiccitation.firstpage","16"],["dc.bibliographiccitation.journal","Biological Conservation"],["dc.bibliographiccitation.lastpage","23"],["dc.bibliographiccitation.volume","226"],["dc.contributor.author","Weier, Sina M."],["dc.contributor.author","Grass, Ingo"],["dc.contributor.author","Linden, Valerie M. G."],["dc.contributor.author","Tscharntke, Teja"],["dc.contributor.author","Taylor, Peter J."],["dc.date.accessioned","2019-07-23T07:50:05Z"],["dc.date.available","2019-07-23T07:50:05Z"],["dc.date.issued","2018"],["dc.description.abstract","Accelerating land use change is associated with the loss of species and their ecosystem services. South Africa is the world's largest producer of macadamias and the industry continues to grow. Insectivorous bat species are important for pest control, but bat populations are declining. Therefore, proactive management of bat communities in agricultural landscapes is essential. We acoustically monitored bats and used light traps to catch arthropods during one annual cycle, sampling five macadamia orchards monthly in Limpopo, South Africa. We used GIS and R to analyse both the general bat and foraging bat activity of the two main foraging guilds (open-air/clutter edge guild) in different land use types and total activity with respect to arthropod abundances. Overall clutter edge guild activity (number of passes) decreased with macadamia and orchard (all other fruit) cover in the high season and increased with bush cover and distance to settlements (potential roosts) in the low season. Open-air guild activity increased with fallow cover in the high season. Foraging activity (feeding buzzes) of the clutter edge guild increased with bush cover over the whole year. Total activity (both guilds) increased with abundance of true bugs, including the main macadamia pests, and bush cover. In conclusion, natural and semi-natural vegetation promote bat activity in macadamia orchards, and potentially bats' provision of the ecosystem service of pest control. In times of accelerating land use change, remnants of natural vegetation are important refuges and need to be maintained or restored. The installation of bathouses might further improve bat activity."],["dc.identifier.doi","10.1016/j.biocon.2018.07.017"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/61872"],["dc.language.iso","en"],["dc.relation.issn","0006-3207"],["dc.title","Natural vegetation and bug abundance promote insectivorous bat activity in macadamia orchards, South Africa"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","e00626"],["dc.bibliographiccitation.journal","Global Ecology and Conservation"],["dc.bibliographiccitation.volume","18"],["dc.contributor.author","Weier, Sina M."],["dc.contributor.author","Moodley, Yoshan"],["dc.contributor.author","Fraser, Mischa F."],["dc.contributor.author","Linden, Valerie M. G."],["dc.contributor.author","Grass, Ingo"],["dc.contributor.author","Tscharntke, Teja"],["dc.contributor.author","Taylor, Peter J."],["dc.date.accessioned","2019-07-23T07:14:47Z"],["dc.date.available","2019-07-23T07:14:47Z"],["dc.date.issued","2019"],["dc.description.abstract","The diet of insectivorous bat species is difficult to study and the least invasive tool to gain information on these predators’ foraging preferences is the study of their faecal pellets.The aim of this study was to determine whether bats consumed insect pest species in macadamia orchards, with the additional goal of incentivising farmers to adopt a more integrated pest management approach (IPM). We used a molecular approach to provide insight into insectivorous bat diet, analysing pellets with fluorescent-labelled and speciesspecific primers (COI). Faecal pellets were collected from captured individuals or from trays installed underneath bathouses and roosts between July 2015 and April 2017 in the Levubu region, Limpopo, South Africa. Four of the main insect pests, two moth (Lepidoptera: Tortricidae) and two stinkbug (Hemiptera: Pentatomidae) species, were collected for species-specific primer development and assay optimisation. We extracted DNA from the faecal pellets and amplified the target regions of the four target pest species present. To verify the results of the fragment analyses we also sequenced all PCR products. All the species or families of bats from which pellets were collected foraged on at least one of the four major insect pests, with insect pest sequences obtained and confirmed from 57 out of 103 samples (55%). Bats consumed insect pests throughout the macadamia growing seasons and are much more generalist and presumably opportunistic feeders than previously assumed. Nearly all species and families of bats analysed foraged on both the Lepidopteran and Hemipteran insect pest species. In conclusion, bats appear to be important for pest control and we suggest that farmers should maintain or restore (semi-) natural vegetation inside and adjacent to their farms. Adding water sources and roosting opportunities, and minimizing pesticide treatments may furthermore promote bat activity."],["dc.identifier.doi","10.1016/j.gecco.2019.e00626"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/61863"],["dc.language.iso","en"],["dc.relation.issn","2351-9894"],["dc.title","Insect pest consumption by bats in macadamia orchards established by molecular diet analyses"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","11"],["dc.bibliographiccitation.journal","Agriculture, Ecosystems & Environment"],["dc.bibliographiccitation.lastpage","18"],["dc.bibliographiccitation.volume","260"],["dc.contributor.author","Grass, Ingo"],["dc.contributor.author","Meyer, Svenja"],["dc.contributor.author","Taylor, Peter J."],["dc.contributor.author","Foord, Stefan H."],["dc.contributor.author","Hajek, Peter"],["dc.contributor.author","Tscharntke, Teja"],["dc.date.accessioned","2019-07-23T08:14:10Z"],["dc.date.available","2019-07-23T08:14:10Z"],["dc.date.issued","2018"],["dc.description.abstract","There is growing demand for pollination services in agricultural production, which contrasts with declines of wild and managed pollinator populations. Macadamia (Macadamia integrifolia) is a mass-flowering crop that depends on pollination services and is increasingly cultivated in South Africa. We studied the crop's pollination in South African orchards considering variation in landscape context and the spatial arrangement of managed honeybees (Apis mellifera). We conducted pollination experiments and pollinator observations on macadamia trees along a distance gradient from orchard edges that bordered either near-natural or human-modified habitats. In addition, we mapped position and density of honeybee apiaries at orchard-level. Nut set of macadamia trees strongly relied on animal-mediated pollination: pollinator exclusion reduced the initial nut set (3 weeks after pollination) by 80% and the final nut set (15 weeks after pollination) by 54%. Supplemental hand-pollination of otherwise untreated flowers increased initial and final nut set by 66% and 44%, respectively, indicating substantial pollination limitation. The landscape context only weakly affected pollinator visitation to macadamia trees, with reduced visitation closer to orchard edges bordering human-modified habitats. Furthermore, we observed almost no wild pollinator species. Instead, honeybees constituted 99% of all visits, whereby honeybee visitation rates increased with a tree's connectivity to apiaries. However, neither initial nor final nut was related to visitation rates, and the final nut set was actually reduced where honeybee colony density was high, with a predicted 50% reduction in final nut set between the lowest and highest colony densities. Our study demonstrates a strong pollination limitation in South African macadamia orchards, where managed honeybees fail at delivering the increasing need for pollination services. Indeed, increasing their colony densities may further limit their pollination efficiency. A pollination management that also includes non-Apis managed pollinators and wild pollinators is possibly needed to increase nut set and provide solutions for increasing pollination service demands. In intensive macadamia orchards, this can also necessitate the need for more pollinator-friendly management practices, including habitat restoration and reduced pesticide application."],["dc.identifier.doi","10.1016/j.agee.2018.03.010"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/61882"],["dc.language.iso","en"],["dc.relation.issn","0167-8809"],["dc.title","Pollination limitation despite managed honeybees in South African macadamia orchards"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","S0167880921002929"],["dc.bibliographiccitation.firstpage","107588"],["dc.bibliographiccitation.journal","Agriculture, Ecosystems & Environment"],["dc.bibliographiccitation.volume","320"],["dc.contributor.author","Weier, Sina M."],["dc.contributor.author","Linden, Valerie M.G."],["dc.contributor.author","Hammer, Antonia"],["dc.contributor.author","Grass, Ingo"],["dc.contributor.author","Tscharntke, Teja"],["dc.contributor.author","Taylor, Peter J."],["dc.date.accessioned","2021-10-01T09:57:25Z"],["dc.date.available","2021-10-01T09:57:25Z"],["dc.date.issued","2021"],["dc.identifier.doi","10.1016/j.agee.2021.107588"],["dc.identifier.pii","S0167880921002929"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/89835"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-469"],["dc.relation.issn","0167-8809"],["dc.title","Bat guilds respond differently to habitat loss and fragmentation at different scales in macadamia orchards in South Africa"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.contributor.author","Taylor, Peter J."],["dc.contributor.author","Grass, Ingo"],["dc.contributor.author","Foord, Stefan"],["dc.contributor.author","Alberts, Dries"],["dc.contributor.author","Linden, Valerie"],["dc.contributor.author","Weier, Sina"],["dc.contributor.author","Maphote, Terrence"],["dc.contributor.author","Tscharntke, Teja"],["dc.date.accessioned","2017-11-29T15:56:52Z"],["dc.date.available","2017-11-29T15:56:52Z"],["dc.date.issued","2016"],["dc.fs.externid","751110"],["dc.fs.pkfprnr","11732"],["dc.identifier.fs","623610"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/11246"],["dc.language.iso","en"],["dc.notes.intern","FactScience-Import"],["dc.notes.status","final"],["dc.relation.conference","The 5th International EcoSummit Congress"],["dc.relation.eventend","2016-09-01"],["dc.relation.eventlocation","Montpellier, France"],["dc.relation.eventstart","2016-08-29"],["dc.relation.ispartof","5th Ecosummit, Montpellier"],["dc.title","Ecosystem services and disservices of birds, bats and ants in subtropical fruit crops in southern Africa"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","e6954"],["dc.bibliographiccitation.journal","PeerJ"],["dc.bibliographiccitation.volume","7"],["dc.contributor.author","Weier, Sina M."],["dc.contributor.author","Linden, Valerie M. G."],["dc.contributor.author","Grass, Ingo"],["dc.contributor.author","Tscharntke, Teja"],["dc.contributor.author","Taylor, Peter J."],["dc.date.accessioned","2019-07-09T11:51:29Z"],["dc.date.available","2019-07-09T11:51:29Z"],["dc.date.issued","2019"],["dc.description.abstract","The loss of roost sites is one of the major drivers of the worldwide decline in bat populations and roost site preferences, either natural or artificially provided, are not well known for African bat species specifically. In this study we focus on the preference for different artificial roost sites by insectivorous bats in macadamia orchards in northern South Africa. From June 2016 to July 2017 we monitored 31 bat houses, mounted on poles in six macadamia orchards, for presence of bats or other occupants. Twentyone multi-chambered bat houses of three different designs were erected in sets of three. Additionally, five Rocket boxes, four bat houses in sets of two (painted black and white) and one colony bat house were erected. Bats were counted and visually identified to family or species level. From December 2016 to the end of March 2017 iButtons were installed to record and analyze temperature variation within one set of three bat houses. We related the occupancy of bat houses to the different types of houses and the environmental variables: distance to water, altitude and height of the bat houses above the ground. Overall bat house occupancy was significantly higher in the central bat house, in the set of three, and the black bat house, in the set of two. Mean temperatures differed between houses in the set of three with the central bat house having a significantly higher mean temperature than the houses flanking it. Our study might confirm previous assumptions that the microclimate of bat houses appears to be an important factor influencing occupancy. In conclusion, from the different bat houses tested in this study the designs we assume the warmest and best insulated attracted the most bats. Further research is needed on the preferred microclimate of different bat species, co-habitation within bat houses and the potential importance of altitude and distance to water. Our study provided little variation in both altitude and the distance to water."],["dc.identifier.doi","10.7717/peerj.6954"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/16138"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/59958"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.subject.ddc","630"],["dc.title","The use of bat houses as day roosts in macadamia orchards, South Africa"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.journal","Journal of Applied Ecology"],["dc.contributor.author","Linden, Valerie M. G."],["dc.contributor.author","Grass, Ingo"],["dc.contributor.author","Joubert, Elsje"],["dc.contributor.author","Tscharntke, Teja"],["dc.contributor.author","Weier, Sina M."],["dc.contributor.author","Taylor, Peter J."],["dc.date.accessioned","2019-07-23T06:57:03Z"],["dc.date.available","2019-07-23T06:57:03Z"],["dc.date.issued","2019"],["dc.description.abstract","1.The relative importance of ecosystem services and disservices can change with landscape structure in a poorly understood way. 2.We compare the impact of biocontrol, provided by bats and birds, with that of crop raiding by vervet monkeys on yield in South African macadamia orchards. Insectivorous bats and birds are known to feed on macadamia pest insect species, like the macadamia nut borer or the green vegetable bug. Vervet monkeys move into the orchards during the day to feed on premature macadamia nuts. Bats, birds and monkeys benefit from patches of natural vegetation adjacent to orchards. 3.With exclusion experiments (four treatments: day, night, day & night, control) we quantified the relative importance of biocontrol and crop raiding on yield, comparing two different landscape settings of the orchards, a natural and a human‐modified. 4.Crop raiding occurred only close to natural vegetation and caused yield losses of about 26%. Biocontrol by bats and birds was higher near natural vegetation, but still significant in human‐modified landscapes, at up to 530m distance to forest patches. Prevented biocontrol through the exclusion of bats and birds resulted in yield losses of up to 60%. 5.Effects of biocontrol by bats and birds (USD ~5000/ha/yr) were economically more important than the losses of crop raiding (USD ~1600/ha/yr). As both are linked to the vicinity of forest patches, the removal of natural vegetation to limit monkey abundances would also limit biocontrol service provision. 6.Synthesis and applications. This study highlights the high economic benefits of biocontrol by bats and birds, which outweighed negative impacts through yield losses caused by crop‐raiding monkeys. Management practices to prevent crop damage, such as guarding, excluding vertebrates or removal of adjacent natural vegetation, would also limit access for bats and birds and the great economic benefits provided by their biocontrol. Ecosystem services by bats and birds can be promoted by the exposure of artificial roost and nest sites, but research into species‐specific preferences is needed. The education of farmers is crucial, as many are unaware of the benefits from birds and bats and the fact that these benefits can outweigh the disadvantages of the monkeys’ crop‐raiding."],["dc.identifier.doi","10.1111/1365-2664.13424"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/61856"],["dc.language.iso","en"],["dc.relation.issn","0021-8901"],["dc.relation.issn","1365-2664"],["dc.title","Ecosystem services and disservices by birds, bats and monkeys change with macadamia landscape heterogeneity"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]