Land maxing in cultivated ecosystems can improve upon other agroecological approaches because in this approach social, economic and ecological benefits are maximized within the available land, in part through the careful selection of plant species with specific benefits, e.g., biodiversity conservation, provision of ecological services, diversifying and improving farmer incomes. In this approach, plant species selected for improving farmer incomes are those providing non-timber marketable products, and plant species selected for biodiversity conservation and provision of ecological services can be identified quantitatively via ecological network theory. Here, we demonstrate using ecological network theory to identify (a) farm management practices associated with ecological network indices, and (b) key plant species that farmers can plant to maximize the potential for their land to support bees and pollination services. In this study we quantified bee-plant interaction networks within 10 agroforests, and compared results between the entire bee community and the subsetted stingless bee community. Bee abundance increased with flowering plant richness, explaining 9% of the variance (R 2 = 0.09; β = 0.05, SE = 0.03). Diverse agroforests with higher numbers of tree species supported less connected (R 2 = 0.67; β = -0.08, SE = 0.02), less nested (R 2 = 0.53; β = -0.05, SE = 0.01), and more specialized (R 2 = 0.63; β = 0.07, SE = 0.02) and modular (R 2 = 0.37; β = 0.05, SE = 0.02) bee-plant networks. Some key plant species with the strongest impacts on network structure and stability were shared between the entire bee-plant and the stingless bee-plant networks. We recommend that farmers plant the species highlighted in this study to maximize the value of their diverse agroforests to support bee communities and pollination services.

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Magnolia pugana (Iltis & A. Vazquez) A. Vázquez & Carvajal, an endemic Mexican species of the Magnoliaceae family, has received limited phytochemical and pharmacological attention. This study reports, for the first time, the chemical composition and in vitro bioactivities of essential oils (EOs) obtained from its leaves, flowers, and seeds. EOs were analyzed by gas chromatography-mass spectrometry (GC-MS) and flame ionization detection (GC-FID), revealing cyclocolorenone, a sesquiterpene, as the major compound (38-40%) across all plant parts. Antioxidant activity was evaluated using DPPH• and ABTS• radical scavenging assays, complemented by bioautographic thin-layer chromatography (TLC). Antibacterial activity was determined by minimum inhibitory concentration (MIC) against human pathogenic bacteria, while cytotoxicity was assessed in MCF-7 (breast) and HT-29 (colon) cancer cell lines. Seed and flower EOs exhibited the highest antioxidant activity, with IC 50 values of 21.5 mg/mL and 9.04 mg/mL, respectively. Strong antibacterial effects were observed against Gram-positive strains, particularly Staphylococcus epidermidis (MIC = 355.11 µg/mL) and S. aureus (MIC = 710.23 µg/mL). Leaf EO showed selective cytotoxicity toward MCF-7 cells (IC 50 = 27.25 µg/mL), while seed EO was most active against HT-29 cells (IC 50 = 54.01 µg/mL). These results suggest that M. pugana EOs, especially those from seeds, are a promising source of natural antioxidant, antimicrobial, and anticancer agents.

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Background Montanoa guatemalensis is a small to medium-sized tree in the Asteraceae that grows in Central America from Mexico south through Costa Rica. There have been no previous investigations on the essential oil of this tree. Methods The leaf essential oils of M. guatemalensis were obtained from different individual trees growing in Monteverde, Costa Rica, in two different years, and were analyzed by gas chromatography-mass spectrometry. Results The leaf oils from 2008 were rich in sesquiterpenoids, dominated by α-selinene, β-selinene, and cyclocolorenone, with lesser amounts of the monoterpenes α-pinene and limonene. In contrast, the samples from 2009 showed no α- or β-selinene, but large concentrations of trans -muurola-4(14),5-diene, β-cadinene, and cyclocolorenone, along with greater concentrations of α-pinene and limonene. The leaf oils were screened for cytotoxic and antimicrobial activities and did show selective cytotoxic activity on MDA-MB-231 breast tumor cells. Conclusion M. guatemalensis leaf oil, rich in cyclocolorenone, α-selinene, and β-selinene, showed selective in vitro cytotoxic activity to MDA-MB-231 cells. The plant may be a good source of cyclocolorenone.

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Measuring plant chlorophyll concentration is a well-known and commonly used method in agriculture and environmental applications for monitoring plant health, which also correlates with many other plant parameters including, e.g., carotenoids, nitrogen, maximum green fluorescence, etc. Direct chlorophyll measurement using chemical extraction is destructive, complex and time-consuming, which has led to the development of mobile optical readers, providing non-destructive but at the same time relatively expensive tools for evaluation of plant chlorophyll levels. Here we demonstrate accurate measurement of chlorophyll concentration in plant leaves using Google Glass and a custom-developed software application together with a cost-effective leaf holder and multi-spectral illuminator device. Two images, taken using Google Glass, of a leaf placed in our portable illuminator device under red and white (i.e., broadband) light-emitting-diode (LED) illumination are uploaded to our servers for remote digital processing and chlorophyll quantification, with results returned to the user in less than 10 seconds. Intensity measurements extracted from the uploaded images are mapped against gold-standard colorimetric measurements made through a commercially available reader to generate calibration curves for plant leaf chlorophyll concentration. Using five plant species to calibrate our system, we demonstrate that our approach can accurately and rapidly estimate chlorophyll concentration of fifteen different plant species under both indoor and outdoor lighting conditions. This Google Glass based chlorophyll measurement platform can display the results in spatiotemporal and tabular forms and would be highly useful for monitoring of plant health in environmental and agriculture related applications, including e.g., urban plant monitoring, indirect measurements of the effects of climate change, and as an early indicator for water, soil, and air quality degradation.

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Coffee agroforestry systems and secondary forests have been shown to support similar bird communities but comparing these habitat types are challenged by potential biases due to differences in detectability between habitats. Furthermore, seasonal dynamics may influence bird communities differently in different habitat types and therefore seasonal effects should be considered in comparisons. To address these issues, we incorporated seasonal effects and factors potentially affecting bird detectability into models to compare avian community composition and dynamics between coffee agroforests and secondary forest fragments. In particular, we modeled community composition and community dynamics of bird functional groups based on habitat type (coffee agroforest vs. secondary forest) and season while accounting for variation in capture probability (i.e. detectability). The models we used estimated capture probability to be similar between habitat types for each dietary guild, but omnivores had a lower capture probability than frugivores and insectivores. Although apparent species richness was higher in coffee agroforest than secondary forest, model results indicated that omnivores and insectivores were more common in secondary forest when accounting for heterogeneity in capture probability. Our results largely support the notion that shade-coffee can serve as a surrogate habitat for secondary forest with respect to avian communities. Small coffee agroforests embedded within the typical tropical countryside matrix of secondary forest patches and small-scale agriculture, therefore, may host avian communities that resemble those of surrounding secondary forest, and may serve as viable corridors linking patches of forest within these landscapes. This information is an important step toward effective landscape-scale conservation in Neotropical agricultural landscapes.

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