Abstract1. Ecological intensification involves the incorporation of biodiversity-based ecosystem service management into farming systems in order to make crop production more sustainable and reduce reliance on anthropogenic inputs, including fertilizer and insecticides.2. The benefits of effectively managing ecosystem services such as pollination and pest regulation for improved yields have been demonstrated in a number of studies, however, recent evidence indicates that these benefits interact with conventional agronomic inputs such as fertilizer and irrigation. Despite the important contribution of biodiversity-based ecosystem services to crop production their management is rarely considered in combination with more conventional agronomic inputs.3. This study combines a number of complementary approaches to evaluate the impact of insect pollination on yield parameters of Brassica napus and how this interacts with a key agronomic input, fertilizer. We incorporate data from a flight cage trial and multiple field studies to quantify the relationships between yield parameters to determine whether insufficient insect pollination may limit crop yield.4. We demonstrate that, by producing larger seeds and more pods, B. napus has the capacity to modulate investment across yield parameters and buffer sub-optimal inputs of fertilizer or pollination. However, only when fertilizer is not limiting can the crop benefit from insect pollination, with yield increases due to insect pollination only seen under high fertilizer application. 5. A nonlinear relationship between seed set per pod and yield per plant was found, with increases in seed set between 15 and 25 seeds per pod resulting in a consistent increase in crop yield. The capacity for the crop to compensate for lower seed set due to sub-optimal pollination is therefore limited. Synthesis and applications.Oilseed rape has the capacity to compensate for suboptimal agronomic or ecosystem service inputs although this has limitations.Insect pollination can increase seed set and so there are production benefits to be gained through effective management of wild pollinators or by utilizing managed species. Our study demonstrates, however, that increased insect pollination cannot simply replace other inputs, and if resources such as fertilizer are limiting, then | 2835Journal of Applied Ecology GARRATT eT Al.

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While an increasing number of studies indicate that the range, diversity and abundance of many wild pollinators has declined, the global area of pollinator-dependent crops has significantly increased over the last few decades. Crop pollination studies to date have mainly focused on either identifying different guilds pollinating various crops, or on factors driving spatial changes and turnover observed in these communities. The mechanisms driving temporal stability for ecosystem functioning and services, however, remain poorly understood. Our study quantifies temporal variability observed in crop pollinators in 21 different crops across multiple years at a global scale. Using data from 43 studies from six continents, we show that (i) higher pollinator diversity confers greater inter-annual stability in pollinator communities, (ii) temporal variation observed in pollinator abundance is primarily driven by the three-most dominant species, and (iii) crops in tropical regions demonstrate higher inter-annual variability in pollinator species richness than crops in temperate regions. We highlight the importance of recognizing wild pollinator diversity in agricultural landscapes to stabilize pollinator persistence across years to protect both biodiversity and crop pollination services. Short-term agricultural management practices aimed at dominant species for stabilizing pollination services need to be considered alongside longer term conservation goals focussed on maintaining and facilitating biodiversity to confer ecological stability.

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Mining in Zambia has left a legacy of degraded land that is unsuitable for most forms of agriculture, and contaminated land surrounds numerous mining towns in the Copperbelt. As mining activities decline, communities are left heavily impacted by the negative environmental and social conditions surrounding them. The challenge is to understand and promote an effective revegetation approach that is economically productive, providing environmental benefits, employment, and diversification. Pongamia pinnata (L.) Pierre, a tree member of the Fabaceae family, has generated interest as a potentially sustainable biofuel feedstock. It produces seeds with high oil content and Pongamia reforestation systems can potentially provide a perennial climate change resilient, drought tolerant, carbon negative alternative to annual oilseed crops for the provision of oil and biomass products capable of providing fuel and food protein products. Additionally, Pongamia can be cultivated in degraded and/or marginal land and, given its phytoremediation potential, it is an ideal candidate for the regeneration of the Copperbelt area. Our study aimed to gain a broader understanding of the potential of P. Pinnata as a phytoremediation tool in the Copperbelt. We have carried out bioassays to assess the toxicity of copper (Cu) in the tailings and measured copper concentrations in both the tailings and the organic amendment around the trees, and in Pongamia roots and leaves growing in a large-scale field trial. Results show high survival rates (98.95%) at relatively high levels of Cu in the tailings (2,997.42 mg.kg -1 on average), with Pongamia trees exhibiting normal development 4 months after being transplanted. Our results suggest that elite Pongamia trees have the potential to be a viable option as a phytoremediation tool in the Copperbelt of Zambia.