Alien success has frequently been associated with changes in the concentrations of soil nutrients. We aim to investigate the effects of plant invasion on soil nutrients, potential enzyme activity and litter elemental composition and stoichiometry. We compared stands of secondary forest invaded by Ligustrum lucidum and those dominated by natives, and performed litter chemical analyses on 3 native and 2 exotic tree species. Soils of invaded sites had 20 and 30 % increase in β-glucosidase and alkaline phosphatase activity, higher Olsen-phosphorus (P) and potassium (K) concentrations and lower nitrogen (N) concentration and N:P, N:K and ammonium:Olsen-P ratios. Invaded and non-invaded sites differed in their overall nutrient composition and enzyme activity. Natives and exotics differed in nine of the 16 litter elemental composition and stoichiometry variables analyzed. The low N:P ratio in litter, the decrease in soil N in invaded stands and the low N concentration of exotics suggest that N is the limiting nutrient and that exotic success is related to higher N uptake and use efficiency. The higher investment in the acquisition of soil resources, higher nutrient uptake and use efficiency of limiting nutrients contribute to the success of exotics in this subtropical forest.

Deforestation linked to agricultural activities is a major sustainability concern. Planning towards sustainable agricultural landscapes in the (sub-)tropics requires indicators that capture the many aspects of social-ecological cost and benefit of agriculture. Agricultural production strategies are developed using the best available data and knowledge such as high-yield locations, distance to storage facilities, or certification bonuses. However, there is often a divide between sustainable production data generated by the scientific community and current data that are of interest to actors, such as those in the agribusiness sector. Here, we describe how the harmonization of crop production, conservation, and social data used by scientists and agribusiness is possible using a participatory exercise based on knowledge co-production (i.e., generation of knowledge in a collaborative way) of socio-economic and environmental indicators (such as agricultural production, logistics, or the location of indigenous communities). This was made available through an online decision support platform that facilitated the generation of sustainable entrepreneurial strategies. We tested this exercise for the social-environmentally vulnerable Argentine Chaco dry forest, subject to some of the highest rates of deforestation globally, mainly due to soybean production. The cooperation between participants of this exercise built a knowledge exchange network that was key for informing decision-makers and highlighted information gaps including agricultural productivity, accessibility of regions, and the vulnerability of rural communities. Our exercise may be applicable to other agricultural commodity frontiers and showcases the value of including actors’ priorities in the design of indicators to ensure their policy impact and to achieve food systems’ sustainability.

Soybean (Glycine max) is a predominantly self-pollinating crop; however, its flowers exhibit traits associated with insect pollination. While several studies report yield benefits from floral visitation, others suggest little or no effect, and few have assessed pollen limitation through direct hand-pollination experiments. Here, we assess pollinator contribution and pollen limitation through two manipulative common garden experiments using different soybean cultivars. First, we assessed the contribution of pollinators by comparing reproductive variables between caged (pollinator excluded) and open-pollinated plants over two growing seasons. Second, we supplemented flowers with cross-pollen to test for pollen limitation, evaluating pollen-tube growth, pod set, seed number per pod, and seed weight. Pollinator exclusion did not significantly reduce total pod or seed production per plant, but open pollination increased seed set (seeds per flower) by ~16%. In contrast, hand supplementation substantially improved reproductive success at the flower level, tripling pod set probability and increasing seed number per pod by 40%. Additionally, both open-pollinated and hand-pollinated flowers exhibited higher pollen-tube growth relative to autonomous selfing. These findings highlight that even in largely self-compatible crops like soybean, additional pollen input can enhance reproductive success and help bridge the gap between the ecological and agronomic dimensions of pollination.