The interactions between pairs of native and alien plants via shared use of pollinators have been widely studied. Community level studies however, are necessary in order to fully understand the factors and mechanisms that facilitate successful plant invasion, but these are still scarce. Specifically, few community level studies have considered how differences in invasion level (alien flower abundance), and degree of floral trait similarity between native and invasive species, mediate effects on native plant-pollinator communities. Here, we evaluated the role of alien species on overall plant-floral visitor network structure, and on species-level network parameters, across nine invaded coastal communities distributed along 205 km in Yucatán, México that vary in alien species richness and flower abundance. We further assessed the potential the role of alien plant species on plant-floral visitor network structure and robustness via computational simulation of native and invasive plant extinction scenarios. We did not find significant differences between native and alien species in their functional floral phenotypes or in their visitation rate and pollinator community composition in these invaded sites. Variation in the proportion of alien plant species and flower abundance across sites did not influence plant-pollinator network structure. Species-level network parameters (i.e., normalized degree and nestedness contribution) did not differ between native and alien species. Furthermore, our simulation analyses revealed that alien species are functionally equivalent to native species and contribute equally to network structure and robustness. Overall, our results suggest that high levels of floral trait similarity and pollinator use overlap may help facilitate the integration of alien species into native plant-pollinator networks. As a result, alien species may also play a similar role than that of natives in the structure and stability of native plant and pollinator communities in the studied coastal sand dune ecosystem.

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This study assessed the in vitro anthelmintic (AH) activity of methanol and acetone:water leaf extracts from Annona squamosa, A. muricata and A. reticulata against Haemonchus contortus eggs. The egg hatch test was used to determine the effective concentrations required to inhibit 50% of eggs hatching (EC50). The role of polyphenols on AH activity was measured through bioassays with and without polyvinylpolypyrrolidone (PVPP). Methanolic extracts mainly caused the death of eggs at the morula stage (ovicidal activity). Meanwhile, acetone:water extracts caused egg-hatching failure of developed larvae (larvae failing eclosion (LFE) activity). The lowest EC50 values against H. contortus eggs were observed for the methanolic extracts from A. reticulata and A. muricata (274.2 and 382.9 µg/ml, respectively). From the six extracts evaluated, the methanolic extracts of A. muricata, A. reticulata and A. squamosa showed the highest ovicidal activity, resulting in 98.9%, 92.8% and 95.1% egg mortality, respectively. When the methanolic extract of A. squamosa was incubated with PVPP, its AH activity increased. Similarly, when acetone:water extracts of A. muriata and A. reticulata were incubated with PVPP, their LFE activity increased. Alkaloids were only evident in methanolic extracts, irrespective of PVPP incubation. The presence of acetogenins was not observed. In conclusion, methanolic extracts obtained from leaves of A. muricata, A. reticulata and A. squamosa showed ovicidal activity affecting the morula of H. contortus eggs, with minor LFE activity. Meanwhile, acetone:water extracts showed mostly LFE activity, with a lower proportion of ovicidal activity.

Goats browsing in a tropical deciduous forest (TDF) obtain a large proportion of their diet from a large number of plant species. Nevertheless, the goat’s feed resource selection has not been studied in such an ecosystem. This study aimed to determine whether goats browsing in a TDF display active feed resource selection. Two browsing sites were used (A = 2.2 ha and B = 2.6 ha). The effective availability (g) of all plant species available was measured for each site using 10 m × 20 m exclusion quadrants. Three non-pregnant adult goats (34.9 ± 2.4 kg liveweight) with browsing experience were observed using the continuous bite monitoring method to determine their respective dry matter intake. The selection of different plants was determined using the Jacobs’ selection index (JSI). The goats’ dry matter intake per day was 723 and 310.8 g for Sites A and B, respectively. At both browsing sites, the plant with the highest biomass availability was Gymnopodium floribundum (75.5% and 49.3% for Sites A and B, respectively). Nevertheless, the plant species most actively selected by goats were Eragrostis ciliaris at Site A (JSI = 0.99, P < 0.05) and Mimosa bahamensis at Site B (JSI = 0.96, P < 0.05). Some plant species were not consumed at Sites A and B (three and five species, respectively). In conclusion, feed resource selection was not associated with the biomass availability of the plants selected or refused. Goats were able to show active feed resource selection in the TDF, and this could change according to the characteristics of the browsing site.

During the rainy season, the tropical deciduous forest (TDF) supposedly represents an abundance of biomass for sheep and goats. Nevertheless, quantitative estimations of feed intake during the rainy season are lacking. This study investigated the feeding behaviour of sheep and goats in a TDF in Mexico and quantified their nutrient intake during the rainy season. Plant species (PS) consumed, size and weight of bites, and nutritional quality were determined by continuous bite monitoring through direct observation. Adult ewes (n = 3) and goats (n = 3) were observed in their grazing circuits (4 h/day) for 12 days during the rainy season. Sheep and goats consumed 61 PS and performed a similar median number of bites (1751 vs 2053 bites/day, respectively; P &gt; 0.05). Although they shared 52.5% of the PS consumed, only seven PS contributed most of the dry matter intake (DMI) for sheep (96.7%) or goats (90.5%). Sheep consumed more grass than goats (79.8% vs 48.3% of their DMI, respectively), whereas goats ate more shrubs than sheep (30.0% vs 7.6% of their DMI, respectively). The diet ingested by goats included more polyphenols (P &lt; 0.05) and a higher frequency of larger and heavier bites than sheep (P &lt; 0.05). Sheep reached 61.3% and 57.7% of their metabolisable energy and crude protein maintenance requirements. Similarly, goats covered 63.3% of their metabolisable energy and 108.2% of crude protein requirement. Although the main ration of sheep and goats was composed of similar PS, their different feeding behaviour resulted in different macronutrient consumption.