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Declining soil fertility limits smallholder macadamia productivity in Malawi. In order to reverse this trend, it is essential to apply organic and inorganic fertilisers in an efficient and effective manner. Yet, fertiliser recommendations for smallholder macadamia (Macadamia integrifolia) production in Malawi are not site-specific. Nutrient imbalances can occur if fertilisers are applied without a clear understanding of whether they are required or not. This may lead to yield losses, unnecessary costs, and other environmental issues associated with excess fertiliser application. To address this knowledge gap, our study examined the current soil fertility status among smallholder macadamia farms in Malawi. Specifically, the objective was to establish an evidence base for promoting soil fertility restoration interventions for smallholder macadamia production. One hundred and eighty nine soil samples at a depth of 0–15 cm were collected from sixty three smallholder macadamia farms belonging to the Highlands Macadamia Cooperative Union Limited members in central and southern Malawi. We found that the majority of the soils were sandy loams (52%), strongly acidic (mean pH ≤ 5.1), and deficient in essential nutrients required for the healthy growth of macadamia. The soils had an average low cation exchange capacity of 1.67 cmol (+) kg− 1, which is inadequate for macadamia cultivation. Over half of the sampled soils had very low organic matter content (≤ 1%). The low soil organic matter content, coupled with the sandy texture and high acidity, contributed to the observed low concentrations of essential nutrients and cation exchange capacity. Poor agronomic practices and the long-term uptake of nutrients by macadamia trees and annual crops are responsible for this low soil fertility. Altogether, our findings underscore the urgent need to identify and implement more sustainable and effective soil nutrient management practices that help to improve the soil fertility of macadamia farms under smallholder systems.

The world faces increasing freshwater supply challenges, fueled partly by rising demand as well as mismanagement of existing resources. This necessitates an aware and engaged public as well as sound water resource management that is supported by data-driven scientific knowledge. Often the public lacks sufficient awareness to participate in resource management; and too often scientists and decision-makers struggle to obtain sufficient good quality data (across time and space scales) to effect change. Citizen science offers a powerful tool to tackle both these challenges by providing efficient and effective ways to obtain useful data while educating citizens about water issues. This article uses examples to describe the role of citizen science, the opportunities available for engagement and identifies criteria for success.

Macadamia (Macadamia integrifolia) nuts have become an essential commodity crop in Malawi. The nuts are a lucrative commodity and are used for household consumption and income generation among farming families and as a foreign exchange earning crop at country-level. In addition, macadamia production has increased significantly in recent years in the country. Currently, Malawi is the seventh top producer of macadamia nuts, with a global market share of three percent (1,846 metric tonnes on kernel basis). In 2018, exports of macadamia kernel had a value of US$24.3 million (£19.8 million or MKW 18.01 billion). However, the bulk (85%) of the crop is grown on large commercial plantations, but the smallholder sector is emerging as vital for the future growth of the macadamia sub-sector in Malawi. Furthermore, Malawian smallholders consider macadamia production to be a low-input crop with large returns per unit area (US$14.37 kg-1ha-1 or MKW 10,701kg-1ha-1) thus a lucrative crop with high potential for poverty reduction and wealth creation among these farming families. This paper, therefore, explores: (i) the historical and current trends in macadamia nut production in Malawi; (ii) analyses the country’s macadamia value chain and (iii) discusses the constraints of macadamia production in Malawi for informed policymaking. Thus, the synthesis of the Malawian macadamia sub-sector provides an understanding of the vital contributions of macadamias to Malawi’s economic growth and improvement of livelihoods.

We currently face significant, anthropogenic, global environmental challenges, and the role of ecologists in mitigating these challenges is arguably more important than ever. Consequently there is an urgent need to recruit and train future generations of ecologists, both those whose main area is ecology, but also those involved in the geological, biological, and environmental sciences.Here we present the results of a horizon scanning exercise that identified current and future challenges facing the teaching of ecology, through surveys of teachers, students, and employers of ecologists. Key challenges identified were grouped in terms of the perspectives of three groups: students, for example the increasing disconnect between people and nature; teachers, for example the challenges associated with teaching the quantitative skills that are inherent to the study of ecology; and society, for example poor societal perceptions of the field of ecology.In addition to the challenges identified, we propose a number of solutions developed at a workshop by a team of ecology teaching experts, with supporting evidence of their potential to address many of the problems raised. These proposed solutions include developing living labs, teaching students to be ecological entrepreneurs and influencers, embedding skills‐based learning and coding in the curriculum, an increased role for learned societies in teaching and learning, and using new technology to enhance fieldwork studies including virtual reality, artificial intelligence and real‐time spoken language translation.Our findings are focused towards UK higher education, but they should be informative for students and teachers of a wide range of educational levels, policy makers and professional ecologists worldwide.

Climate change is altering suitable areas of crop species worldwide, with cascading effects on people reliant upon those crop species as food sources and for income generation. Macadamia is one of Malawi’s most important and profitable crop species; however, climate change threatens its production. Thus, this study’s objective is to quantitatively examine the potential impacts of climate change on the climate suitability for macadamia in Malawi. We utilized an ensemble model approach to predict the current and future (2050s) suitability of macadamia under two Representative Concentration Pathways (RCPs). We achieved a good model fit in determining suitability classes for macadamia (AUC = 0.9). The climatic variables that strongly influence macadamia’s climatic suitability in Malawi are suggested to be the precipitation of the driest month (29.1%) and isothermality (17.3%). Under current climatic conditions, 57% (53,925 km2) of Malawi is climatically suitable for macadamia. Future projections suggest that climate change will decrease the suitable areas for macadamia by 18% (17,015 km2) and 21.6% (20,414 km2) based on RCP 4.5 and RCP 8.5, respectively, with the distribution of suitability shifting northwards in the 2050s. The southern and central regions of the country will suffer the greatest losses (≥ 8%), while the northern region will be the least impacted (4%). We conclude that our study provides critical evidence that climate change will reduce the suitable areas for macadamia production in Malawi, depending on climate drivers. Therefore area-specific adaptation strategies are required to build resilience among producers.

Macadamia is an essential commodity crop in Malawi. The nuts are a lucrative commodity and are used for household consumption, income generation among farming families and as a foreign exchange earning crop at country-level. Macadamia production in Malawi has increased significantly in recent years. Malawi is the seventh top producer of macadamia nuts valued at £23.5 million, with a global market share of 3%. In 2018, the country was the fourth-largest exporter of macadamia nuts that were valued at £18.2 million. The majority (90%) of this crop was grown by large commercial estates with smallholder’s production only contributing about 10% of the total crop production. However, the smallholder sector is vital for the future growth of the macadamia sector in the country. Further, Malawian smallholders consider macadamia production as a low-input crop with large returns per unit area (£10.7 kg−1 ha−1), and it thus a lucrative commodity with high potential for poverty reduction and wealth creation among these farming families. This paper, therefore, explores: (i) the historical and current trends in macadamia nut production in Malawi; (ii) analyses the country’s macadamia value chain focusing on smallholder farmer contributions; and (iii) discusses the constraints of smallholder macadamia production in Malawi for informed policymaking. We conclude that the synthesis of the Malawian macadamia sub-sector provides an understanding of the vital contributions of macadamia to Malawi’s economic growth and improvement of livelihoods.

The ecosystem services framework (ESF) is advantageous and widely used for itemising and quantifying ways in which humans benefit from natural places. However, it suffers from two important problems: (i) incoherence of definitions and (ii) a narrow approach to valuation, inadequate to represent the full range of human motives for conservation and the diverse interests of different stakeholders. These shortcomings can lead to a range of problems including double-counting, blind spots and unintended consequences. In this opinion article, we propose an ecosystem valuing framework as a broader and more rigorous way to deliver the benefits currently sought from the ESF, without the conceptual problems.

Wetland restoration frequently sets well-defined vegetation targets, but where restoration occurs on highly degraded land such targets are not practical and setting looser targets may be more appropriate. Where this more ‘open-ended’ approach to restoration is adopted, surveillance methods that can track developing wetland habitats need to be established. Water regime and soil structure are known to influence the distribution and composition of developing wetland vegetation, and may be quantified using Sum Exceedence Values (SEV), calculated using the position of the water table and knowledge of soil stress thresholds. Use of SEV to explain patterns in naturally colonizing vegetation on restored, ex-arable land was tested at Wicken Fen (UK). Analysis of values from ten locations showed that soil structure was highly heterogeneous. Five locations had shallow aeration stress thresholds and so had the potential to support diverse wetland assemblages. Deep aeration stress thresholds at other locations precluded the establishment of a diverse wetland flora, but identified areas where species-poor wetland assemblages may develop. SEV was found to be a useful tool for the surveillance of sites where restoration targets are not specified in detail at the outset and may help predict likely habitat outcomes at sites using an open-ended restoration approach.

Background:\ud Hedges are oth ecologically and culturally important and are a distinctive feature of the British landscape. However the overall length of hedges across Great Britain is decreasing. Current challenges in studying hedges relate to the dominance of research on rural, as opposed to urban, hedges, and their variability and geographical breadth. To help address these challenges and to educate the public on the importance of hedge habitats for wildlife, in 2010 the Open Air Laboratories (OPAL) programme coordinated a hedge-focused citizen science survey.\ud \ud Results:\ud Results from 2891 surveys were analysed. Woody plant species differed significantly between urban and rural areas. Beech, Holly, Ivy, Laurel, Privet and Yew were more commonly recorded in urban hedges whereas Blackthorn, Bramble, Dog Rose, Elder and Hawthorn were recorded more often in rural hedges. Urban and rural differences were shown for some groups of invertebrates. Ants, earwigs and shieldbugs were recorded more frequently in urban hedges whereas blowflies, caterpillars, harvestmen, other beetles, spiders and weevils were recorded more frequently in rural hedges. Spiders were the most frequently recorded invertebrate across all surveys. The presence of hard surfaces adjacent to the hedge was influential on hedge structure, number and diversity of plant species, amount of food available for wildlife and invertebrate number and diversity. In urban hedges with one adjacent hard surface, the food available for wildlife was significantly reduced and in rural hedges, one adjacent hard surface affected the diversity of invertebrates.\ud \ud Conclusions:\ud This research highlights that urban hedges may be important habitats for wildlife and that hard surfaces may have an impact on both the number and diversity of plant species and the number and diversity of invertebrates. This study demonstrates that citizen science programmes that focus on hedge surveillance can work and have the added benefit of educating the public on the importance of hedgerow habitats.

Citizen science has been gaining momentum in the United States and Europe, where citizens are literate and often interested in science. However, in developing countries, which have a dire need for environmental data, such programs are slow to emerge, despite the large and untapped human resources in close proximity to areas of high biodiversity and poorly known floras and faunas. Thus, we propose that the parataxonomist and paraecologist approach, which originates from citizen-based science, is well suited to rural areas in developing countries. Being a paraecologist or a parataxonomist is a vocation and entails full-time employment underpinned by extensive training, whereas citizen science involves the temporary engagement of volunteers. Both approaches have their merits depending on the context and objectives of the research. We examined 4 ongoing paraecologist or parataxonomist programs in Costa Rica, India, Papua New Guinea, and southern Africa and compared their origins, long-term objectives, implementation strategies, activities, key challenges, achievements, and implications for resident communities. The programs supported ongoing research on biodiversity assessment, monitoring, and management, and participants engaged in non-academic capacity development in these fields. The programs in Southern Africa related to specific projects, whereas the programs in Costa Rica, India, and Papua New Guinea were designed for the long term, provided sufficient funding was available. The main focus of the paraecologists' and parataxonomists' activities ranged from collection and processing of specimens (Costa Rica and Papua New Guinea) or of socioeconomic and natural science data (India and Southern Africa) to communication between scientists and residents (India and Southern Africa). As members of both the local land user and research communities, paraecologists and parataxonomists can greatly improve the flow of biodiversity information to all users, from local stakeholders to international academia.

1. The growing literature on the phylogenetic structure of plant communities places great emphasis on the role of phylogenetic niche conservatism (PNC) in community assembly. However, the patterns revealed by such analyses are difficult to interpret in the absence of independent data on niche structure. While there is increasing evidence that plant coexistence does depend upon niche differences, it is still not clear in most cases what the relevant niche axes are. 2. We address this problem by testing for PNC within the African Restionaceae (‘restios’), a clade endemic to the Western Cape where we have shown niche segregation along soil moisture gradients to be common. 3. Significant niche segregation on soil moisture gradients occurred among restios in 7 of 10 communities sampled, but PNC was detectable in only one of these and then only by one of three methods used. 4. Phylogenetic analysis of the evolution of hydrological niche traits for the species pool of 37 Restionaceae in the study showed tolerance of drought to be convergent rather than conserved. 5. Synthesis. The demonstration that clear niche segregation may occur among related species without PNC being detectable supports the hypothesis that hydrological niche responses are evolutionarily labile. More generally, the results demonstrate that phylogenetic analysis can be a poor guide to the process of community assembly. We argue that it may in future be better to apply ecological data to the interpretation of phylogenies, rather than to follow the current preoccupation with the application of phylogenies to ecology.

Questions How is the composition of wet meadow plant communities influenced by water regime? What controls soil nitrogen (N) availability along a gentle soil water regime gradient? Is vegetation response to subtle changes in soil water regime mediated by N availability? Location Cricklade, Wiltshire, southwest England. Methods A field survey of community composition and soil N availability was conducted along a gentle gradient of water table depth (mean water table depth between 25 and 70 cm) at a species-rich hay meadow in southwest England. This study was complemented by a controlled mescosm study undertaken at water table depths between 5 and 45 cm, and a controlled laboratory N mineralization study with water tension varying between 0 and 100 cm (0–10 kPa), the latter augmented with a microbial community study. Results The field, mesocosm and laboratory studies showed that the soil N mineralization rate and N availability responded to water regime. In particular, the N mineralization rate strongly declined when the soil air-filled pore space dropped below 10% of total soil volume. In the field, plant cover distribution (individual species as well as functional groups) correlated with increase in soil water table depth (r = −0.86 and r = 0.89 for graminoids and forbs, respectively) and soil N availability (r = 0.77 and r = −0.85, respectively). A switch in dominance between forbs and graminoids occurred at a mean water table depth of 55 cm and mean soil inorganic N of 20 mg·kg −1 ). Study of the soil microbial community composition in the mesocosms, using phospholipid fatty acid (PLFA) signatures, showed that microbial community composition was also significantly influenced by soil water status. Conclusions We show that soil moisture content and soil aeration control the availability of N, a limiting nutrient, in species-rich wet meadows. The mechanism is linked to changes in suitability of the soil water regime for microbially mediated N mineralization. Maintaining the water regime is therefore critical because adjustment of the hydrological niche also conditions species' responses along the N availability gradient. This could subsequently prove a useful tool for conservation managers trying to sustain a target vegetation type.

Background and aims Species in plant communities segregate along fine-scale hydrological gradients. Although this phenomenon is not unique to fynbos, this community regenerates after fire and therefore provides an opportunity to study the ecological genesis of hydrological niche segregation. Methods Following wildfires at two field sites where we had previously mapped the vegetation and monitored the hydrology, seeds were moved experimentally in >2500 intact soil cores up and down soil-moisture gradients to test the hypothesis that hydrological niche segregation is established during the seedling phase of the life cycle. Seedling numbers and growth were then monitored and they were identified using DNA bar-coding, the first use of this technology for an experiment of this kind. Key Results At the site where niche segregation among Restionaceae had previously been found, the size of seedlings was significantly greater, the wetter the location into which they were moved, regardless of the soil moisture status of their location of origin, or of the species. Seedling weight was also significantly greater in a competition treatment where the roots of other species were excluded. No such effects were detected at the control site where niche segregation among Restionaceae was previously found to be absent. Conclusions The finding that seedling growth on hydrological gradients in the field is affected by soil moisture status and by root competition shows that hydrological niche segregation could potentially originate in the seedling stage. The methodology, applied at a larger scale and followed-through for a longer period, could be used to determine whether species are differently affected by soil moisture

Consistent, repeatable segregation of plant species along hydrological gradients is an established phenomenon that must in some way reflect a trade-off between plants' abilities to tolerate the opposing constraints of drought and waterlogging. In C3 species tissue carbon isotope discrimination (δ13C) is known to vary sensitively in response to stomatal behaviour, reflecting stomatal limitation of photosynthesis during the period of active growth. However, this has not been studied at fine-spatial scale in natural communities. We tested how δ13C varied between species and sexes of individuals in the family Restionaceae growing along a monitored hydrological gradient. Twenty Restionaceae species were investigated using species-level phylogeny at two sites in the Cape Floristic Region, a biodiversity hotspot. A spatial overlap analysis showed the Restionaceae species segregated significantly (P < 0.001) at both sites. Moreover, there were significant differences in δ13C values among the Restionaceae species (P < 0.001) and between male and female individuals of each species (P < 0.01). However, after accounting for phylogeny, species δ13C values did not show any significant correlation with the hydrological gradient. We suggest that some other variable (e.g. plant phenology) could be responsible for masking a simple response to water availability.

Crop residues are an important component of N cycling in the agro-ecosystem. In this study, a loam soil was amended with cabbage residues and the N mineralization from soil organic matter and residues, as well as N uptake by Italian rye grass, were investigated. Four mineral fertilizer-residue combination treatments and two application times were tested in micro-plots. For uncropped micro-plots, application of residue resulted in higher soil mineral N content (43 mg N kg−1, 63 days post application) versus 30.5 mg N kg−1 for an unamended soil. Both bulked dry matter production and N uptake by the rye grass decreased in the order full mineral fertilizer > half mineral fertilizer + half residue > full residue applied 3 weeks before sowing > full residue applied at sowing, but the differences were more pronounced in the N uptake. Shoot N recovery from the applied residue (27.5–31.4%) was much smaller than that from the full fertilizer (70.2%), but was still considerable. Apparent net N mineralizatio...

A method was developed to maintain water-table depths at a constant level in outdoor mesocosms. The system included a water treatment reservoir, where tap water was microbially deoxygenated and denitrified; an adjustable-level control chamber that set desired water table-depths and plant growing mesocosms.\ud \ud The soil water status was evaluated by constant monitoring using tensiometers, pressure transducers and dipwells. The robustness of the system was tested by inducing sudden incidents of flooding and drainage. The system was able to revert to the original set water-table depths within 5 and 10 minutes respectively. It also reliably sustained consistent water-table depths throughout the growing season without the need for maintenance.\ud \ud As an example, the method was used to grow plants at five set water-table depths: 50, 150, 250, 350, and 450 mm below ground surface. Two wet grassland species Festuca pratensis (meadow fescue), and Carex nigra (common sedge) were grown and dry biomass production recorded. Results showed differences in growth response between the two species to subjected water-table depths. In monoculture, F. pratensis production followed the order 50 = 150 = 350 > 250 = 450 mm (p 50 = 350 = 450 mm (pF. pratensis did not show a significant trend (p < 0.06), whereas C. nigra showed 50 = 150 > 250 > 350 = 450 mm (p

1. Despite the fundamental significance of water to plants and the persisting question of how competing species coexist, this is the first review of hydrological niches. We define hydrological niche segregation (HNS) as: (i) partitioning of space on fine-scale soil-moisture gradients, (ii) partitioning of water as a resource, and/or (iii) partitioning of recruitment opportunities among years caused by species specializing on particular patterns of temporal variance of water supply (the storage effect).\ud 2. We propose that there are three types of constraint that lead to the trade-offs that underlie HNS. (i) An edaphic constraint creates a trade-off between the supply to roots of O2 on the one hand vs. water and nutrients on the other. (ii) A biophysical constraint governs gas exchange by leaves, leading to a trade-off between CO2 acquisition vs. water loss. (iii) A structural constraint arising from the physics of water-conducting tissues leads to a safety vs. efficiency trade-off. \ud 3. Significant HNS was found in 43 of 48 field studies across vegetation types ranging from arid to wet, though its role in coexistence remains to be proven in most cases. Temporal partitioning promotes coexistence through the storage effect in arid plant communities, but has yet to be shown elsewhere. In only a few cases is it possible to unequivocally link HNS to a particular trade-off.\ud \ud 4. Synthesis. The field and experimental evidence make it clear that HNS is widespread, though it is less clear what its precise mechanisms or consequences are. HNS mechanisms should be revealed by further study of the constraints and trade-offs that govern how plants obtain and use water and HNS can be mechanistically linked to its consequences with appropriate community models. In a changing climate, such an integrated programme would pay dividends for global change research.

The world faces severe and growing challenges in maintaining water quality and in meeting the rapidly growing demand for water resources. As the present young people will be playing central roles in the future, the importance of understanding their views and paving way for their participation is of utmost importance. The involvement of young people in the “think globally, act locally” vision is illustrated here with the case of an international youth movement, the Young Water Action Team (YWAT 1 ).

Sustainable water management is one of the global grand challenges of our time. Tackling this challenge through cor-rective actions would required the participation of the general public, a public with sound awareness of the challenge and commitment. One such awareness raising intervention could be through the use of water symbolism and proverbs , targeted to particular society. Water has the differing symbolism and levels of importance to people, depending of their personal characteristics and socio-demographic factors (e.g. gender, age, occupation, residence). Similarly, water prov-erbs can also demonstrate attitudes towards water among communities, ethnic groups and whole nations. Such mean-ings and symbolism could help determine attitude and be a powerful tool towards education. In this context, we de-scribe and propose a psychological Health Belief Model (HBM) as a way to explain behaviour and stimulate sustainable water management practice.

Ecologists still puzzle over how plant species manage to coexist with one another while competing for the same essential resources. The classic answer for animal communities is that species occupy different niches, but how plants do this is more difficult to determine. We previously found niche segregation along fine-scale hydrological gradients in European wet meadows and proposed that the mechanism might be a general one, especially in communities that experience seasonal saturation\ud \ud – We quantified the hydrological niches of 96 species from eight fynbos communities in the biodiversity hotspot of the Cape Floristic Region, South Africa and 99 species from 18 lowland wet meadow communities in the UK. Niche overlap was computed for all combinations of species.\ud \ud – Despite the extreme functional and phylogenetic differences between the fynbos and wet meadow communities, an identical trade-off (i.e. specialization of species towards tolerance of aeration and/or drying stress) was found to cause segregation along fine-scale hydrological gradients.\ud \ud – This study not only confirms the predicted generality of hydrological niche segregation, but also emphasizes its importance for structuring plant communities. Eco-hydrological niche segregation will have implications for conservation in habitats that face changing hydrology caused by water abstraction and climate change.

Public awareness of the impending world water crisis is an important prerequisite to create a responsible citizenship capable of participating to improve world water\ud management. In this context, the case of a unique global water education outreach exercise, World Water Monitoring Day of October 18, is presented. Started in 2002\ud in the United States, currently World Water Monitoring Day is celebrated in 50 countries by more than 75,000 particpants per year. Review of this exercise in terms\ud of public environmental education and possible transferrability to to other global issues of importance is discussed.