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- Effect of Row Spacing in the Period Prior to Weed Interference in Peanut Cultivation Under Azorean ConditionsPublication . Parreira, Mariana; Costa, Vasco Rafael Rodrigues; Lopes, David João Horta; de Portugal e Vasconcelos, João Martim; da Silva Madruga, João; Benedito, Vitor Adriano; Campalle, Arthur Nardi; Martins, Heytor LemosABSTRACT: Peanut cultivation currently plays a minor role in Portuguese agriculture, despite the country’s favorable soil and climatic conditions. In the Azores archipelago, where agriculture is a key economic activity, peanut production has recently sparked interest among rural producers. Weeds pose a major threat to crop development, particularly for short-cycle species like peanuts. This study aimed to determine the period prior to weed interference (PPI) in peanut crops under two row spacings (40 cm and 60 cm) on São Miguel Island, Azores. Eight treatments were established—0–15, 0–30, 0–45, 0–60, 0–75, 0–90 days after emergence (DAE), full-season coexistence, and a weed-free control—to represent increasing periods of weed competition. A randomized block design with four replicates was used for each spacing. The weed community included eight species, with Cyperus spp., Digitaria spp., Amaranthus blitum, and Portulaca oleracea being the most prevalent. Weed interference throughout the entire cycle led to yield losses exceeding 81% and 86% at 40 cm and 60 cm row spacings, respectively. The PPI was defined at a 5% yield reduction threshold, which is a commonly accepted benchmark in weed science to determine the beginning of the critical period of weed interference.
- Up from the bottom: Consistent vertical distance-decay in arthropod assemblage similarity across native and exotic forests in Terceira island (Azores)Publication . Lhoumeau, Sébastien Georges André; Borges, P.A.V.ABSTRACT: This study compares the vertical stratification of arthropod assemblages in native and exotic forests on Terceira Island (Azores), focusing on how assemblage similarity decays with increasing vertical distance between strata. We tested three hypotheses: (H1) the overall arthropod assemblage similarity decays with vertical distance; (H2) exotic forests exhibit lower decay rates due to structural simplification; and (H3) the contribution of both indigenous and non-indigenous arthropod assemblages to vertical distance decay differs. Arthropods were sampled across four strata in ten native and ten exotic forest plots using pitfall and SLAM traps. We computed the beta diversity between each strata, partitioning turnover versus richness differences. We found a significant decay in the overall arthropod assemblage similarity with increasing vertical distance, driven primarily by species turnover rather than richness differences. Contrary to predictions, the rate of vertical decay did not differ significantly between native and exotic forests, suggesting that structural simplification in exotic forests does not necessarily reduce vertical stratification. However, the species origin of the arthropods had a significant effect on the vertical distribution patterns, with non indigenous species showing a restricted vertical ranges compared to indigenous species. These findings highlight the significance of incorporating vertical dimensions in biodiversity assessments and conservation strategies, emphasising the pivotal role of species biogeographical origin in shaping vertical community structure in island forest ecosystems.
- The proper middle class: assessing the importance of subordinate species on plant community assembly and functional diversityPublication . Ulrich, Werner; Matthews, Thomas; Biurrun, Idoia; Aleksanyan, Alla; Borovyk, Dariia; Burrascano, Sabina; Campos, Juan Antonio; Chusova, Olha; Czarniecka-Wiera, Marta; Czortek, Patryk; Dembicz, Iwona; Essl, Franz; Janišová, Monika; Labadessa, Rocco; Napoleone, Francesca; Pielech, Remigiusz; Vynokurov, Denys; Puchałka, Radosław; Peres-Neto, PedroABSTRACT: The local species abundance distribution (SAD) and the associated distributions of species functional traits (TADs) both result from the process of plant community assembly. Community assembly has been extensively studied for dominant and rare plants, while subordinates, the species of intermediate abundance in a community, have received less research attention although this group is comparatively species rich and important for community functioning. Here, we study the functional role of subordinate species (those covering the intermediate 50% of abundance ranks) using a large data set of Palearctic dry and semi-dry grassland plant communities and data on specific leaf area, seed mass and plant height. Our findings indicate that species rank orders of SADs and TADs tend to be negatively correlated, causing the TAD to have higher evenness than the associated SAD. Subordinate species represented on average less than 15% of total plant abundance and trait space. Functional diversity of subordinates was lower than expected by a null model that assumed an equiprobable random distribution of trait values among plant species. Climate seasonality and elevation appeared to be the most important drivers of subordinate abundance and functional diversity. We conclude that subordinates differ from dominants in trait composition, leading to their partial functional independence from dominants.
- Ground beetles (Coleoptera: Carabidae) of the Desertas Islands (Madeira archipelago, Portugal): description of a new subspecies and faunistic notesPublication . Serrano, Artur; Aguiar, Carlos; Cardoso, Pedro; Pereira, Fernando; Padro e Castro, Catarina; Rego, Carla; Silva, Isamberto; Canelas Boieiro, Mário RuiABSTRACT: We update the knowledge on the ground beetle fauna (Coleoptera: Carabidae) of the Desertas Islands and provide novel information on species distribution in the three islands (Ilhéu Chão, Deserta Grande and Bugio) following two entomological missions carried out in 2011 and 2012. An annotated checklist of the 33 species and subspecies known to occur in the Desertas Islands is presented, jointly with data on their distribution and ecology. Philorhizus melanocephalus (Dejean) is recorded for the first time for Madeira archipelago, four other taxa are new records for the Desertas Islands: Apotomus chaudoirii Wollaston, Ocys harpaloides (Serville), Paradromius (Manodromius) insularis oceanicus (Wollaston) and Syntomus fuscomaculatus (Motschulsky) and several species are for the first time recorded for specific Desertas’ islands. Furthermore, a new subspecies of the genus Orthomus Chaudoir, 1838 sampled by direct collection in Bugio is described: O. (Nesorthomus) bedelianus isambertoi Serrano & Boieiro, ssp. nov. with its habitus and aedeagus illustrated. The new subspecies is compared with the closely related Orthomus (Nesorthomus) bedelianus bedelianus (Lutshnik) from Madeira Island. A historical review of the research on the ground beetles of the Desertas Islands is presented, along with considerations on beetle species rarity and the conservation measures needed to protect them. This information will be helpful to support biodiversity conservation management in the Desertas Islands.
- Human and Environmental Factors Shape Tree Species Assemblages in West African Tropical ForestsPublication . Asuk, Sijeh; Wayman, Joseph; Sadler, Jonathan; Pugh, Thomas; Matthews, Thomas; Ebu, Vincent; Phillips, Oliver; Lewis, Simon; Sonké; Bonaventure; Talbot, Joey; Comiskey, James; Zemagho, Lise; Ojo, Lucas; Begne, Serge; Taedoumg, Hermann; Sunderland, Terry; Hubau, Wannes; Droissart, Vincent; Qie, Lan; Gilpin, Martin; Simo-Droissart, Murielle; Feldpausch, Ted; Peh, Kelvin; Banin, Lindsay; Kamdem, Marie; Kettridge, Nicholas; Cabral, JulianoABSTRACT: Aim This study investigated how human activities and local environmental variables shape tree assemblages (species composition in a defined location), comparing their effects on edible and inedible tree species. Three hypotheses were tested: (1) Environmental filtering impacts spatial beta-diversity more than dispersal limitation; (2) human activities significantly influence regional tree beta-diversity; and (3) predictors of beta-diversity differ between edible and inedible species. Location Tropical forest in Nigeria and Cameroon in West and Central Africa. Methods Tree data were collected between 2002 and 2019 from 66 forest plots. Species were categorised as edible and inedible by humans using interviews and online databases. Pairwise beta-diversity (partitioned into total beta-diversity and turnover) between plots was analysed using Generalised Dissimilarity Models (GDMs) with geographical distance, plot-specific variables (forest composition, climate, elevation, stem density, human influence indicators), and human influence indicators (distance to closest human presence [DCHP], and nearest anthropogenic edges [DNAE]) as predictors. Results The dataset included 236 edible species (11,097 stems) and 472 inedible species (17,202 stems), with high species turnover (> 90%) dominating beta-diversity patterns. Due to local plot-level factors, environmental filtering (deviance explained for all species: 37.4%, edible: 18.9% and inedible: 31.4%) exerted greater influence on species assemblages than geographical distance alone. Beta-diversity drivers differed between edible and inedible species: elevation strongly influenced turnover in inedible species, whereas forest composition significantly shaped the assemblage of edible species, reflecting patterns of human-mediated species selection and species dominance. Human presence impacted the overall beta-diversity of inedible species but only influenced the turnover component of edible species. Main Conclusions Tree assemblages in the Nigeria–Cameroon forest region were primarily structured by local environmental conditions and human activities rather than by dispersal limitation. Effective conservation should incorporate sustainable human activities and traditional ecological knowledge, with further research needed to explore the long-term anthropogenic impacts on these forests.
- Global synthesis of apple pollination research highlights general pollen limitation and positive contributions of wild bees compared to honeybeesPublication . Eeraerts, Maxime; Osterman, Julia; Batáry, Péter; Klein, Alexandra-Maria; Albrecht, Matthias; Andersson, Georg; Báldi, András; Bernauer, Olivia; Blechschmidt, Leah; Blitzer, Eleanor; Borges, P.A.V.; Bosch, Jordi; Burns, Katherine; Campbell, Alistair; Castro, Silvia; Cook, James; Daelemans, Robin; Danforth, Bryan; Groot, Arjen; Dorji, Kinley; Foldesi, Rita; Day, Hannah; García, Daniel; Garibaldi, Lucas; Garrat, Michael; Gonzalez, Andrew; Grab, Heather; Gratton, Claudio; Halvorsen, Maren; Hamback, Peter; Hatteland, Bjørn; Honnay, Olivier; Hulsmans, Eva; Vestheim, Sandra; Kleijin, David; Kovács-Hostyánszki, Anikó; Lechowicz, Martin; Leclercq, Nicolas; Liu, Yunhui; Loureiro, João; Mallinger, Rachel; Marshall, Leon; Meeus, Ivan; Miñarro, Marcos; Jodar, Diego; Pardo, Adara; Park, Mia; Paxton, Robert; Pérez-Méndez, Néstor; Picante de Carvalho, Rafael; Pirttilehto, Paavo; Pisman, Matti; Potts, Simon; Raine, Nigel; Reilly, James; Roquer-Beni, Laura; Samnegård, Ulrika; Stanley, Dara; Sutter, Louis; Teixeira-Martins, Kyle; Tierney, Simon; Veldtman, Ruan; Vereecken, Nicolas; Wäckers, Felix; Weekers, Timothy; Wilson, Julianna; Wu, Panlong; Verheyen, Kris; Baronio, GudryanABSTRACT: Apple is one of the most important pollinator-dependent fruit crops worldwide. To secure high-quality yields, it is crucial to know which, and to what extent, pollinating insects contribute to its pollination success as measured by fruit set, fruit weight and seed set. We perform a meta-analysis of field studies conducted across multiple orchards on insect-mediated pollination in apple cultivation, using raw data from 29 studies, totalling 532 orchard replicates. We assessed the extent of pollen limitation on different pollination outcomes and assessed the contribution of honeybees, wild bees and bee species richness to apple pollination. Across all studies, we detected strong evidence of pollen limitation for fruit set and seed set, but not for fruit weight. Honeybees were the most abundant flower visitors (average relative visitation of 71.9%) compared to wild bees; but when correcting for their pollination efficiency, the relative pollination contribution of honeybees was lower compared to their relative visitation (vice versa for solitary bees). We conclude that honeybee visitation rate did not influence fruit or seed set; yet increasing honeybee visitation had a small, negative effect on fruit weight. Fruit set was not influenced by wild bee visitation rate, whereas wild bee visitation had a small, but clear positive effect on fruit weight and seed set. Bee species richness had a small, positive effect on seed set; whereas it did not affect fruit set and fruit weight. Syntheses and applications. Our study highlights that pollen limitation is common in this global crop. While managed honeybees are dominant pollinators, a diverse community of wild bees contributes significantly to apple pollination and high-quality yield. The positive effect of wild bees and species richness on fruit weight and seed set demonstrates that wild bee pollination results in better-quality fruit production (increased weight & seed set). Therefore, our synthesis highlights the importance of conserving pollinator diversity to maintain pollination services. The absence of a clear effect of honeybee visitation rate on fruit and seed set, coupled with its negative impact on fruit weight, suggests a need for further optimisation of honeybee management to improve the cost-efficiency of pollination management.
- Effect of Row Spacing in the Period Prior to Weed Interference in Peanut Cultivation Under Azorean ConditionsPublication . Casari Parreira, Mariana; Rodrigues Costa, Vasco Rafael; Horta Lopes, David; Portugal e Vasconcelos, João Martim; Madruga, João; Benedito, Vitor; Campalle, Arthur; Martins, HeytorABSTRACT: Peanut cultivation currently plays a minor role in Portuguese agriculture, despite the country’s favorable soil and climatic conditions. In the Azores archipelago, where agriculture is a key economic activity, peanut production has recently sparked interest among rural producers. Weeds pose a major threat to crop development, particularly for short-cycle species like peanuts. This study aimed to determine the period prior to weed interference (PPI) in peanut crops under two row spacings (40 cm and 60 cm) on São Miguel Island, Azores. Eight treatments were established—0–15, 0–30, 0–45, 0–60, 0–75, 0–90 days after emergence (DAE), full-season coexistence, and a weed-free control—to represent increasing periods of weed competition. A randomized block design with four replicates was used for each spacing. The weed community included eight species, with Cyperus spp., Digitaria spp., Amaranthus blitum, and Portulaca oleracea being the most prevalent. Weed interference throughout the entire cycle led to yield losses exceeding 81% and 86% at 40 cm and 60 cm row spacings, respectively. The PPI was defined at a 5% yield reduction threshold, which is a commonly accepted benchmark in weed science to determine the beginning of the critical period of weed interference.