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Drought stress reduces annual global wheat yields by 20%. Silicon (Si) fertilisation has been proposed to improve plant drought stress tolerance. However, it is currently unknown if and how Si affects different wheat landraces, especially with respect to their innate Si accumulation properties. In this study, significant and consistent differences in Si accumulation between landraces were identified, allowing for the classification of high Si accumulators and low Si accumulators. Landraces from the two accumulation groups were then used to investigate the effect of Si during osmotic and drought stress. Si was found to improve growth marginally in high Si accumulators during osmotic stress. However, no significant effect of Si on growth during drought stress was found. It was further found that osmotic stress decreased Si accumulation for all landraces whereas drought increased it. Overall, these results suggest that the beneficial effect of Si commonly reported in similar studies is not universal and that the application of Si fertiliser as a solution to agricultural drought stress requires detailed understanding of genotype-specific responses to Si.

As water quality and availability decreases in many parts of the world, salinity is becoming a major challenge that reduces crop yield, even in soilless cultivation systems. Therefore, novel strategies are needed to promote plant salt tolerance in these systems. We hypothesized that the non-essential element silicon (Si) and plant-growth promoting Bacillus spp. can alleviate salt stress of cucumber (Cucumis sativus L.) grown in hydroponics. We tested this hypothesis by growing cucumber seedlings with and without salt stress (75 mM NaCl) and with and without 1.5 mM Si and an inoculum of six rhizosphere Bacillus species in a full-factorial design. Seedlings were grown in a climate room for two weeks in independent deep-water culture containers. The applied salt stress strongly reduced plant biomass, whereas Si application under salt stress resulted in a substantial increase in cucumber shoot and root biomass. This beneficial impact of Si was also observed in increased plant height, leaf area, specific leaf area, root length, specific root length, root surface area and root volume. The Bacillus species increased root dry weight, specific leaf area as well as specific root length. In seedlings grown under salt stress, Si application increased shoot and root Si concentration, whereas Cl− concentration was reduced in the plant shoots. A reduction in Cl− concentration of the shoots was also apparent in the Bacillus treatment. Under non-stress conditions, neither Si nor Bacillus species affected plant growth parameters. However, shoot mineral content was affected as Si application reduced shoot Cl−and Ca2+ concentrations, and inoculation with Bacillus species decreased K concentration. We conclude that Si does promote salt stress alleviation during the early growth stage of cucumber grown in deep water culture and this has implications for soilless crop production. Seed inoculation with Bacillus species showed a beneficial trend for some plant growth characteristics and nutrient status under high salinity, although not as pronounced as for Si.

Land‐based enhanced rock weathering (ERW) is a biogeochemical carbon dioxide removal (CDR) strategy aiming to accelerate natural geological processes of carbon sequestration through application of crushed silicate rocks, such as basalt, to croplands and forested landscapes. However, the efficacy of the approach when undertaken with basalt, and its potential co‐benefits for agriculture, require experimental and field evaluation. Here we report that amending a UK clay‐loam agricultural soil with a high loading (10 kg/m2) of relatively coarse‐grained crushed basalt significantly increased the yield (21 ± 9.4%, SE ) of the important C4 cereal Sorghum bicolor under controlled environmental conditions, without accumulation of potentially toxic trace elements in the seeds. Yield increases resulted from the basalt treatment after 120 days without P‐ and K‐fertilizer addition. Shoot silicon concentrations also increased significantly (26 ± 5.4%, SE ), with potential benefits for crop resistance to biotic and abiotic stress. Elemental budgets indicate substantial release of base cations important for inorganic carbon removal and their accumulation mainly in the soil exchangeable pools. Geochemical reactive transport modelling, constrained by elemental budgets, indicated CO2 sequestration rates of 2–4 t CO2/ha, 1–5 years after a single application of basaltic rock dust, including via newly formed soil carbonate minerals whose long‐term fate requires assessment through field trials. This represents an approximately fourfold increase in carbon capture compared to control plant–soil systems without basalt. Our results build support for ERW deployment as a CDR technique compatible with spreading basalt powder on acidic loamy soils common across millions of hectares of western European and North American agriculture.

Grazing‐induced changes in plant quality have been suggested to drive the negative delayed density dependence exhibited by many herbivore species, but little field evidence exists to support this hypothesis. We tested a key premise of the hypothesis that reciprocal feedback between vole grazing pressure and the induction of anti‐herbivore silicon defenses in grasses drives observed population cycles in a large‐scale field experiment in northern England. We repeatedly reduced population densities of field voles (Microtus agrestis) on replicated 1‐ha grassland plots at Kielder Forest, northern England, over a period of 1 year. Subsequently, we tested for the impact of past density on vole life history traits in spring, and whether these effects were driven by induced silicon defenses in the voles’ major over‐winter food, the grass Deschampsia caespitosa. After several months of density manipulation, leaf silicon concentrations diverged and averaged 22% lower on sites where vole density had been reduced, but this difference did not persist beyond the period of the density manipulations. There were no significant effects of our density manipulations on vole body mass, spring population growth rate, or mean date for the onset of spring reproduction the following year. These findings show that grazing by field voles does induce increased silicon defenses in grasses at a landscape scale. However, at the vole densities encountered, levels of plant damage appear to be below those needed to induce changes in silicon levels large and persistent enough to affect vole performance, confirming the threshold effects we have previously observed in laboratory‐based studies. Our findings do not support the plant quality hypothesis for observed vole population cycles in northern England, at least over the range of vole densities that now prevail here.

Non-technical summary Until the past half-century, all agriculture and land management was framed by local institutions strong in social capital. But neoliberal forms of development came to undermine existing structures, thus reducing sustainability and equity. The past 20 years, though, have seen the deliberate establishment of more than 8 million new social groups across the world. This restructuring and growth of rural social capital within specific territories is leading to increased productivity of agricultural and land management systems, with particular benefits for those previously excluded. Further growth would occur with more national and regional policy support. Technical summary For agriculture and land management to improve natural capital over whole landscapes, social cooperation has long been required. The political economy of the later twentieth and early twenty-first centuries prioritized unfettered individual action over the collective, and many rural institutions were harmed or destroyed. Since then, a wide range of social movements, networks and federations have emerged to support transitions towards sustainability and equity. Here, we focus on social capital manifested as intentionally formed collaborative groups within specific geographic territories. These groups focus on: (1) integrated pest management; (2) forests; (3) land; (4) water; (5) pastures; (6) support services; (7) innovation platforms; and (8) small-scale systems. We show across 122 initiatives in 55 countries that the number of groups has grown from 0.50 million (in 2000) to 8.54 million (in 2020). The area of land transformed by the 170–255 million group members is 300 Mha, mostly in less-developed countries (98% groups; 94% area). Farmers and land managers working with scientists and extensionists in these groups have improved both environmental outcomes and agricultural productivity. In some cases, changes to national or regional policy supported this growth in groups. Together with other movements, these social groups could now support further transitions towards policies and behaviours for global sustainability. Social media summary Millions of geographically based new social groups are leading to more sustainable agriculture and forestry worldwide.

Above- and below-ground organisms can interact by altering the quality of shared host plants. Arbuscular mycorrhizal fungi (AMF) influence plant nutrient uptake, including nitrogen (N) acquisition. Under low N and phosphorus conditions, AMF delivery of N from organic sources not immediately available to the plant can have large impacts on plant N status, a limiting nutrient in the aphid diet. This study investigated the effect of AMF colonisation upon aphid number and determined the consequences of AMF directly accessing an organic nutrient patch that the plant cannot. We hypothesised that AMF colonisation of plants will increase plant and aphid N status, plant performance and aphid number, but only when the AMF had direct access to the added organic patch. Barley plants hosting the grain aphid Sitobion avenae were colonised by the AMF, Funneliformis mosseae, or no AMF. A two-compartment microcosm was used to separate the plant roots from a 15 N-labelled organic patch in a second compartment. AMF-colonised plants, but without access to the second compartment, were used to examine the effect of AMF colonisation on aphid number. In a separate treatment, and to determine whether AMF access to a plant inaccessible N source modified the effect of AMF colonisation on aphid number, AMF hyphae were permitted access to the second compartment containing an organic patch. As a control for AMF accessing a larger substrate volume, AMF were allowed access to a second compartment without an organic patch. When the AMF accessed the organic patch, more N from the patch was delivered to the plant resulting in a higher grain N concentration although plant growth was depressed. More N from the patch was also delivered to the aphids, but the N status of the aphid remained unchanged. Regardless of the level of access to the organic patch, AMF colonisation did not affect aphid number. Our data show that by accessing N sources not readily available to plants, AMF can indirectly deliver N to above-ground organisms, a finding which has major implications for N-transfer between higher trophic levels. A plain language summary is available for this article.

The sustainable intensification of agricultural systems offers synergistic opportunities for the co-production of agricultural and natural capital outcomes. Efficiency and substitution are steps towards sustainable intensification, but system redesign is essential to deliver optimum outcomes as ecological and economic conditions change. We show global progress towards sustainable intensification by farms and hectares, using seven sustainable intensification sub-types: integrated pest management, conservation agriculture, integrated crop and biodiversity, pasture and forage, trees, irrigation management and small or patch systems. From 47 sustainable intensification initiatives at scale (each >104 farms or hectares), we estimate 163 million farms (29% of all worldwide) have crossed a redesign threshold, practising forms of sustainable intensification on 453 Mha of agricultural land (9% of worldwide total). Key challenges include investment to integrate more forms of sustainable intensification in farming systems, creating agricultural knowledge economies and establishing policy measures to scale sustainable intensification further. We conclude that sustainable intensification may be approaching a tipping point where it could be transformative.

Arbuscular mycorrhizal fungal (AMF) colonisation of plant roots is one of the most ancient and widespread interactions in ecology, yet the systemic consequences for plant secondary chemistry remain unclear. We performed the first metabolomic investigation into the impact of AMF colonisation by Rhizophagus irregularis on the chemical defences, spanning above- and below-ground tissues, in its host-plant ragwort (Senecio jacobaea). We used a non-targeted metabolomics approach to profile, and where possible identify, compounds induced by AMF colonisation in both roots and shoots. Metabolomics analyses revealed that 33 compounds were significantly increased in the root tissue of AMF colonised plants, including seven blumenols, plant-derived compounds known to be associated with AMF colonisation. One of these was a novel structure conjugated with a malonyl-sugar and uronic acid moiety, hitherto an unreported combination. Such structural modifications of blumenols could be significant for their previously reported functional roles associated with the establishment and maintenance of AM colonisation. Pyrrolizidine alkaloids (PAs), key anti-herbivore defence compounds in ragwort, dominated the metabolomic profiles of root and shoot extracts. Analyses of the metabolomic profiles revealed an increase in four PAs in roots (but not shoots) of AMF colonised plants, with the potential to protect colonised plants from below-ground organisms. Electronic supplementary material The online version of this article (10.1007/s10886-017-0921-1) contains supplementary material, which is available to authorized users.

Ecologists have become increasingly aware that silicon uptake by plants, especially the Poaceae, can have beneficial effects on both plant growth and herbivore defence. The effects of silicon on other plant functional groups, such as nitrogen-fixing legumes, have been less well studied. Silicon could, however, indirectly promote herbivore performance in this group if reported increases in N-2 fixation caused improvements in host plant quality for herbivores. We tested how silicon supplementation in the legume (Medicago sativa) affected plant growth rates, root nodulation and foliage quality (silicon content and amino acid profiles) for an insect herbivore (Acyrthosiphon pisum). Plants supplemented with silicon (Si+) grew three times as quickly as those without supplementation (Si-), almost entirely in shoot mass. While root growth was unaffected by silicon uptake, root nodules containing nitrogen-fixing bacteria were 44% more abundant on Si+ plants. Aphid abundance was twice as high on Si+ plants compared to Si- plants and was positively correlated with silicon-stimulated plant growth. Si+ plants accumulated more than twice as much silicon as Si- plants, but did not have higher silicon concentrations because of dilution effects linked to the rapid growth of Si+ plants. Si+ plants showed a 65% increase in synthesis of essential foliar amino acids, probably due to increased levels of root nodulation. These results suggest that increased silicon supply makes M. sativa more susceptible to A. pisum, mainly because of increased plant growth and resource availability (i.e. essential amino acids). While silicon augmentation of the Poaceae frequently improves herbivore defence, the current study illustrates that this cannot be assumed for other plant families where the beneficial effects of silicon on plant growth and nutrition may promote herbivore performance in some instances.

Climate models predict shifts in the amount, frequency and seasonality of rainfall. Given close links between grassland productivity and rainfall, such changes are likely to have profound effects on the functioning of grassland ecosystems and modify species interactions. Here, we introduce a unique, new experimental platform – DRI-Grass (Drought and Root Herbivore Interactions in a Grassland) – that exposes a south-eastern Australian grassland to five rainfall regimes [Ambient (AMB), increased amount (IA, +50%), reduced amount (RA, -50%), reduced frequency (RF, single rainfall event every 21 days, with total amount unchanged) and summer drought (SD, 12–14 weeks without water, December–March)], and contrasting levels of root herbivory. Incorporation of a belowground herbivore (root-feeding scarabs) addition treatment allows novel investigation of ecological responses to the twin stresses of altered rainfall and root herbivory. We quantified effects of permanently installed rain shelters on microclimate by comparison with outside plots, identifying small shelter effects on air temperature (-0.19°C day, +0.26°C night), soil water content (SWC; -8%) and photosynthetically active radiation (PAR; -16%). Shelters were associated with modest increases in net primary productivity (NPP), particularly during the cool season. Rainfall treatments generated substantial differences in SWC, with the exception of IA; the latter is likely due to a combination of higher transpiration rates associated with greater plant biomass in IA and the low water-holding capacity of the well-drained, sandy soil. Growing season NPP was strongly reduced by SD, but did not respond to the other rainfall treatments. Addition of root herbivores did not affect plant biomass and there were no interactions between herbivory and rainfall treatments in the 1st year of study. Root herbivory did, however, induce foliar silicon-based defenses in Cynodon dactylon and Eragrostis curvula. Rapid recovery of NPP following resumption of watering in SD plots indicates high functional resilience at the site, and may reflect adaptation of the vegetation to historically high variability in rainfall, both within- and between years. DRI-Grass provides a unique platform for understanding how ecological interactions will be affected by changing rainfall regimes and, specifically, how belowground herbivory modifies grassland resistance and resilience to climate extremes.

The distinctive ecology of root herbivores, the complexity and diversity of root-microbe interactions, and the physical nature of the soil matrix mean that plant responses to root herbivory extrapolate poorly from our understanding of responses to aboveground herbivores. For example, root attack induces different changes in phytohormones to those in damaged leaves, including a lower but more potent burst of jasmonates in several plant species. Root secondary metabolite responses also differ markedly, although patterns between roots and shoots are harder to discern. Root defences must therefore be investigated in their own ecophysiological and evolutionary context, specifically one which incorporates root microbial symbionts and antagonists, if we are to better understand the battle between plants and their hidden herbivores.

Understanding the factors that drive species population dynamics is fundamental to biology. Cyclic populations of microtine rodents have been the most intensively studied to date, yet there remains great uncertainty over the mechanisms determining the dynamics of most of these populations. For one such population, we present preliminary evidence for a novel mechanism by which herbivore-induced reductions in plant quality alter herbivore life-history parameters and subsequent population growth. We tested the effect of high silica levels on the population growth and individual performance of voles ( Microtus agrestis ) reared on their winter food plant ( Deschampsia caespitosa ). In sites where the vole population density was high, silica levels in D. caespitosa leaves collected several months later were also high and vole populations subsequently declined; in sites where the vole densities were low, levels of silica were low and population density increased. High silica levels in their food reduced vole body mass by 0.5% a day. We argue that silica-based defences in grasses may play a key role in driving vole population cycles.

Understanding the impact of species on community structure is a fundamental question in ecology. There is a growing body of evidence that suggests that both subdominant species and parasites can have disproportionately large effects on other organisms. Here we report those impacts for a species that is both subdominant and parasitic, the hemiparasite Rhinanthus minor. While the impact of parasitic angiosperms on their hosts and, to a lesser degree, coexisting plant species, has been well characterized, much less is known about their effects on higher trophic levels: We experimentally manipulated field densities of the hemiparasite Rhinanthus minor in a species-rich grassland, comparing the plant and invertebrate communities in plots where it was removed, present at natural densities, or present at enhanced densities. Plots with natural and enhanced densities of R. minor had lower plant biomass than plots without the hemiparasite, but enhanced densities almost doubled the abundance of invertebrates within the plots across all trophic levels, with effects evident in herbivores, predators, and detritivores. The hemiparasite R. minor, despite being a subdominant and transient component within plant communities that it inhabits, has profound effects on four different trophic levels. These effects persist beyond the life of the hemiparasite, emphasizing its role as a keystone species in grassland communities.

Endophytic fungi live asymptomatically within plants. They are usually regarded as non-pathogenic or even mutualistic, but whether plants respond antagonistically to their presence remains unclear, particularly in the little-studied associations between endophytes and nong-raminoid herbaceous plants. \ud \ud We investigated the effects of the endophyte Chaetomium cochlioides on leaf chemistry in Cirsium arvense. Plants were sprayed with spores; leaf material from both subsequent new growth and the sprayed leaves was analysed 2 wk later. Infection frequency was 91% and63% for sprayed and new growth, respectively, indicating that C. cochlioides rapidly infects new foliage.\ud \ud Metabolomic analyses revealed marked changes in leaf chemistry with infection, especially in new growth. Changes in several novel oxylipin metabolites were detected, including arabi-dopsides reported here for the first time in a plant species other than Arabidopsis thaliana,and a jasmonate-containing galactolipid.\ud \ud The production of these metabolites in response to endophyte presence, particularly in newly infected foliage, suggests that endophytes elicit similar chemical responses in plants to those usually produced following wounding, herbivory and pathogen invasion. Whether en-dophytes benefit their hosts may depend on a complex series of chemically mediated interactions between the plant, the endophyte, other microbial colonists and natural enemies.

Grasses have been considered to primarily employ tolerance in lieu of defense in mitigating damage caused by herbivory. Yet a number of mechanisms have been identified in grasses, which may deter feeding by grazers. These include enhanced silicon uptake, hosting of toxin-producing endophytic fungi and induction of secondary metabolites. While these mechanisms have been individually studied, their synergistic responses to grazing, as well as their effects on grazers, are poorly known. A field experiment was carried out in 5 × 5 m outdoor enclosures to quantify phytochemical changes of either endophyte-infected (E+) or endophyte-free (E-) meadow fescue (Schedonorus pratensis) in response to medium intensity (corresponding with densities of ca. 1200 voles / ha for 5 weeks during 3 months) or heavy intensity (ca. 1200 voles / ha for 8 weeks during 3 months) grazing by a mammalian herbivore, the field vole (Microtus agrestis). A laboratory experiment was then conducted to evaluate the effects of endophyte infection status and grazing history of the grass diet on vole performance. As predicted, grazing increased foliar silicon content, by up to 13 %. Grazing also increased foliar levels of phosphorous and several phenolic compounds, most notably those of the flavonols isorhamnetin-diglycoside and rhamnetin derivative. Silicon concentrations were consistently circa 16 % higher in E+ grasses than in E-grasses, at all levels of grazing. Similarly, concentrations of chlorogenic acid derivative were found to be consistently higher in E+ than in E- grasses. Female voles maintained on heavily grazed grasses suffered higher mortality rates in the laboratory than female voles fed ungrazed grass, regardless of endophyte infection status. Our results conclusively demonstrate that, in addition to tolerance, grasses employ multi-tiered, effective defenses against mammalian grazers.

Predicted increases in atmospheric carbon dioxide (CO2) concentrations often reduce nutritional quality for herbivores by increasing the C:N ratio of plant tissue. This frequently triggers compensatory feeding by aboveground herbivores, whereby they consume more shoot material in an attempt to meet their nutritional needs. Little, however, is known about how root herbivores respond to such changes. Grasslands are particularly vulnerable to root herbivores, which can collectively exceed the mass of mammals grazing aboveground. Here we provide novel evidence for compensatory feeding by a grass root herbivore, Sericesthis nigrolineata, under elevated atmospheric CO2 (600 µmol mol(-1)) on a C3 (Microlaena stipoides) but not a C4 (Cymbopogon refractus) grass species. At ambient CO2 (400 µmol mol(-1)) M. stipoides roots were 44% higher in nitrogen (N) and 7% lower in carbon (C) concentrations than C. refractus, with insects performing better on M. stipoides. Elevated CO2 decreased N and increased C:N in M. stipoides roots, but had no impact on C. refractus roots. Root-feeders displayed compensatory feeding on M. stipoides at elevated CO2, consuming 118% more tissue than at ambient atmospheric CO2. Despite this, root feeder biomass remained depressed by 24%. These results suggest that compensatory feeding under elevated atmospheric CO2 may make some grass species particularly vulnerable to attack, potentially leading to future shifts in the community composition of grasslands.

Elevated atmospheric CO2 can change foliar tissue chemistry. This alters leaf litter palatability to macroinvertebrate detritivores with consequences for decomposition, nutrient turnover, and food-web structure. Currently there is no consensus on the link between CO2 enrichment, litter chemistry, and macroinvertebrate-mediated leaf decomposition. To identify any unifying mechanisms, we presented eight invertebrate species from aquatic and terrestrial ecosystems with litter from Alnus glutinosa (common alder) or Betula pendula (silver birch) trees propagated under ambient (380 ppm) or elevated (ambient +200 ppm) CO2 concentrations. Alder litter was largely unaffected by CO2 enrichment, but birch litter from leaves grown under elevated CO2 had reduced nitrogen concentrations and greater C/N ratios. Invertebrates were provided individually with either (i) two litter discs, one of each CO2 treatment (‘choice’), or (ii) one litter disc of each CO2 treatment alone (‘no-choice’). Consumption was recorded. Only Odontocerum albicorne showed a feeding preference in the choice test, consuming more ambient- than elevated-CO2 birch litter. Species’ responses to alder were highly idiosyncratic in the no-choice test: Gammarus pulex and O. albicorne consumed more elevated-CO2 than ambient-CO2 litter, indicating compensatory feeding, while Oniscus asellus consumed more of the ambient-CO2 litter. No species responded to CO2 treatment when fed birch litter. Overall, these results show how elevated atmospheric CO2 can alter litter chemistry, affecting invertebrate feeding behaviour in species-specific ways. The data highlight the need for greater species-level information when predicting changes to detrital processing–a key ecosystem function–under atmospheric change.

† Background and Aims The herbivore defence system of true grasses (Poaceae) is predominantly based on silicon that is taken up from the soil and deposited in the leaves in the form of abrasive phytoliths. Silicon uptake mechanisms can be both passive and active, with the latter suggesting that there is an energetic cost to silicon uptake. This study assessed the effects of plant-available soil silicon and herbivory on the competitive interactions between the grasses Poa annua, a species that has previously been reported to accumulate only small amounts of silicon, and Lolium perenne, a high silicon accumulator. † Methods Plants were grown in mono- and mixed cultures under greenhouse conditions. Plant-available soil silicon levels were manipulated by adding silicon to the soil in the form of sodium silicate. Subsets of mixed culture pots were exposed to above-ground herbivory by desert locusts (Schistocerca gregaria). † Key Results In the absence of herbivory, silicon addition increased biomass of P. annua but decreased biomass of L. perenne. Silicon addition increased foliar silicon concentrations of both grass species .4-fold. Under low soil-silicon availability the herbivores removed more leaf biomass from L. perenne than from P. annua, whereas under high silicon availability the reverse was true. Consequently, herbivory shifted the competitive balance between the two grass species, with the outcome depending on the availability of soil silicon. † Conclusions It is concluded that a complex interplay between herbivore abundance, growth– defence trade-offs and the availability of soil silicon in the grasses’ local environment affects the outcome of inter-specific competition, and so has the potential to impact on plant community structure.

A plan for Post Market Environmental Monitoring (PMEM) of genetically modified (GM) plants is mandatory in all applications for deliberate release submitted under EU Directive 2001/18/EC and EU Regulation 1829/2003. PMEM is composed of case-specific monitoring and general surveillance of GM plants. The European Food Safety Authority (EFSA) is responsible for assessing the scientific quality of PMEM plans submitted with each application. In a scientific opinion, the EFSA GMO Panel presented specific guidance for applicants for developing PMEM plans. In addition the EFSA GMO Panel explained the scientific rationale for this guidance and makes a number of recommendations for the management and conduct of PMEM by both applicants and risk managers. Until the end of March 2007, the EFSA GMO Panel gave opinions on 11 PMEM plans submitted under EU Directive 2001/18/EC and another 11 plans submitted within applications under EU Regulation 1829/2003. Currently 27 applications for GM plants are still in the evaluation process and the EFSA GMO Panel sent 26 questions to the applicants for clarification and additional information during the evaluation process. Sixteen of these questions were related to General Surveillance (e.g. general structure, farm & operator questionnaires, integrations of identity preservation systems, use of existing surveillance systems, feral plant surveillance). Nine questions requested clarification on the environmental risk assessment, which might effect whether case-specific monitoring is needed. In one case (an application for cultivation of a GM crop), the GMO Panel recommended case-specific monitoring. We explain in more detail how the environmental risk assessment of two Bt maize dossiers (maize Bt11 and 1507) were considered by the GMO Panel in the evaluation of the PMEM plan and the consequences for the environmental monitoring plan. As stated in the EFSA opinion on post-market environmental monitoring, the general surveillance plans shall, when possible, make use of existing monitoring systems in addition to more focused monitoring systems. However, the use of these national monitoring programmes is outside of the management and control of an individual applicant and thus it cannot be the task of an applicant alone to use, modify or improve existing surveillance systems. The availability of biodiversity monitoring programmes in the EU Member States should be evaluated by applicants in close liaison with risk managers.