Modelling the functional dynamics of Carabid assemblages as indicators of agroecosystem stability = Ukubumba uguquko olusebenzayo lweCarabids njengezinkomba zokuzinza kohlelonhlaliswano yokuphilayo nokungaphili kwezolimo.

Abstract

Carabid beetles (Coleoptera: Carabidae) are ubiquitous and critically important in agroecosystems. Their rapid response to anthropogenic disturbances has been proposed as a practical and realistic tool for monitoring the sustainability of agricultural management practices. Carabid beetles significantly control pest populations, thereby aiding the regulation of harmful insects in agroecosystems. Recognizing their significance in this context highlights the potential of natural pest control strategies that can decrease reliance on chemical pesticides. Despite their potential importance, the impact of agricultural management practices on the diversity patterns and functionality of carabid beetles, specifically in South Africa, remains largely unexplored. Addressing this research gap is imperative to understand the complex association between agroecosystem management practices and carabid beetle populations in this region. This study aimed to advance knowledge about the ecological stability of diversely managed agroecosystems under conventional tillage, semi-natural grassland, conservation grazing, and semi-conservation agriculture by documenting and assessing the status of carabid beetle biodiversity and utilizing their functionality. This was done by (1) systematically reviewing literature on carabids as indicators of sustainability in agroecosystems, (2) assessing the diversity and community structure of carabid beetles in response to contrasting agroecosystem management, (3) investigating carabid beetle concordance with the selected epigeic arthropod taxa (ground spiders, ants, and rove beetles), and (4) characterizing carabid functional diversity (body size, feeding preference/guilds, and wing morphology). I achieved the aims by sampling over a two-year period, from 2020 to 2021, in the Free State province of South Africa using pitfall traps and active search methods. Carabid beetles were classified into morphospecies, and their functional diversity was determined using existing literature on carabid beetles. Data were analyzed with a sequence of multivariate and spatial statistical methods using the R software version 3.4.2. Carabid taxonomic and functional diversity patterns were significantly supported in conservation grazing compared with conventional tillage, semi-natural grassland, and semi-conservation agroecosystems. Notably, the conservation grazing-associated species included large flightless predators from the genera Calosoma and Scarites. Large, immobile, and specialized carabid beetles are sensitive indicators of management intensity in agricultural landscapes. However, not all carabid species are vulnerable to disturbances; some are eurytopic, occurring across all agroecosystems, such as the carabid genus Pterostichus, which are generalists and exhibit tolerance to disturbances. There was a high degree of congruence between the species richness and composition of carabid beetles and the overall epigeic arthropod taxa, indicating the efficacy of using carabid beetles as proxies for predicting the arthropod diversity patterns of epigeic taxa and identifying farms with conservation significance. The use of carabid beetles as model organisms in agroecosystems serves as a reliable proxy for assessing the impact of management practices on agroecosystems, enabling the ranking of disturbance, recovery, and stability levels. This knowledge will facilitate informed decision making and the implementation of effective conservation and sustainable management practices.

Iqoqa.

Amabhungane iCarabid (Coleoptera: Carabidae) atholakala yonke indawo futhi abaluleke kakhulu ohlelweninhlaliswano yokuphilayo nokungaphili kwezolimo. Ukusabela kwabo ngokushesha ekuphazamisekeni kwesinukubalisi esikhiqizwa abantu kuye kwahlongozwa njengensizakusebenza yangokoqobo loqobo ukuqapha ukusimama kwezinqubo zokuphatha ezolimo. Amabhungane e-Carabid alawula kakhulu izinambuzane, ngaleyo ndlela asize ukulawula izinambuzane eziyingozi enhlaliswaneniyokuphiayo nokungaphili kwezolimo. Ukubona ukubaluleka kwazo kulo mongo kugqamisa amandla amasu emvelo okulawula izinambuzane anganciphisa ukuthembela kuzibulalanambuzane zamakhemikhali. Naphezu kokubaluleka kwazo okungase kube khona, umthelela wezinqubo zokuphatha ezolimo namaphethini anokuhlukahluka okusebenza kwamabhungane ecarabid, ikakhulukazi eNingizimu Afrika, akukahlolisiswa. Ukubhekana naleli gebe locwaningo kubalulekile ukuqonda ukuhlangana okuyinkimbinkimbi phakathi kwemikhuba yokuphatha inhlaliswano yokuphilayo nokungaphili kwezolimo kanye nenani lebhungane lecarabid kulesi sifunda. Lolu cwaningo beluhlose ukuqhubekisela phambili ulwazi mayelana nokuzinza kwemvelo kwezinhlelo zezolimo ezilawulwa ngendlela ehlukahlukene ngaphansi kokulinywa okujwayelekile, utshani obuncane bemvelo, amadlelo alondolozayo, kanye nezolimo ezingalondoloziwe ngokubhala kanye nokuhlola isimo sempiliswanomvelo yebhungane icarabid nokusebenzisa ukusebenza kwawo. Lokhu kwenziwa (1) ngokubuyekeza ngokuhlelekile izincwadi ezikhuluma ngecarabid njengezinkomba zokusimama kohlelonhlaliswano yokuphilayo nokukngaphili kwezolimo, (2) ukuhlola ukuhlukahluka kanye nesakhiwo somphakathi wamabhungane ecarabid ekuphenduleni ekuphathweni okuhlukile kohlelonhlaliswano yokupilayo nokukngaphili kwezolimo, (3) ukuphenya ukuhambisana kwebhungane le-carabid nemisundu ekhethiwe. Izinhloonhlobo zezilokazane (izicabucabu zaphansi, izintuthwane, namabhungane e-rove), kanye (4) nezimpawu ezihlukahlukene zokusebenza kwecarabid (usayizi womzimba, okuthandwayo okuphakelayo/izinhlangano, kanye nokumila kwamaphiko). Ngifeze izinhloso ngokuthatha amasampula esikhathini esiyiminyaka emibili, kusukela ngowezi-2020 kuya kowezi-2021, esifundazweni saseFreyistata eNingizimu Afrika ngisebenzisa izingibe nezindlela zokusesha ezisebenzayo. Amabhungane eCarabid ahlukaniswa abe yizinhlobosakhiwo, futhi ukuhlukahluka kwawo okusebenzayo kwanqunywa kusetshenziswa izincwadi ezikhona kumabhungane ecarabid. Imininingo yahlaziywa ngokulandelana kwezindlela zezibalo ze-multivariate nezendawo kusetshenziswa i-R software version 3.4.2. Amaphethini e-Carabid taxonomic kanye nokuhlukahluka okusebenzayo asekelwa kakhulu edlelweni lokongiwayo uma kuqhathaniswa nokulinywa okuvamile, indawo yotshani eyingxenye yemvelo, kanye ne-semi-conservation agroecosystems. Ngokuphawulekayo, izinhlobo ezihlotshaniswa namadlelo ekongiweni zazihlanganisa izilwane ezidla ezinye ezingandizi ezivela ohlotsheni lwe-Calosoma ne-Scarites. Amabhungane amakhulu, ezinganyakazi, nezikhethekile ze-carabid ziyizinkomba ezizwelayo zokuqina kokuphatha ezindaweni zezolimo. Nokho, akuzona zonke izinhlobo ze-carabid ezisengozini yokuphazamiseka; ezinye ziyi-eurytopic, zenzeka kuwo wonke ama-agroecosystem, njenge-carabid genus Pterostichus, okungama-generalists futhi abonisa ukubekezelela ukuphazamiseka. Kube nezinga eliphezulu lokusebenzisana phakathi kokunotha kwezinhlobo nokwakheka kwamabhungane e-carabid nazo zonke izinhlobo zemisundu, okubonisa ukusebenza kahle kokusebenzisa amabhungane e-carabid njengama-proxies okubikezela amaphethini okuhlukahluka kwezinhlobo zemisundu kanye nokuhlonza amapulazi anokubaluleka kokongiwa kwemvelo. Ukusetshenziswa kwamabhungane e-carabid njengezinto eziphilayo eziyimodeli ku-agroecosystems kusebenza njengommeleli onokwethenjelwa wokuhlola umthelela wezinqubo zokuphatha ku-agroecosystem, okuvumela izinga lokuphazamiseka, ukululama, kanye namazinga okuqina. Lolu lwazi luzosiza ekuthathweni kwezinqumo nolwazi kanye nokuqaliswa kokugcinwa kwemvelo okusebenzayo kanye nezinqubo zokuphatha ezisimeme.