Linking 'citizen scientists' to professionals in ecological research, examples from Namibia and South Africa

The use of trained members of the public (‘citizen scientists’) to help monitor and collect data in science-driven environmental research projects is not a new concept e.g. the Cornell bird program, USA, has been ‘partnering’ with the public since the 1960s (University of Cornell 2008). However, this concept has yet to find much following in developing countries where often the greatest need for conservation lies. We examine the effectiveness of citizen scientists (‘plant custodians’, ‘paraecologists’ and ‘eco-club volunteers’) in monitoring (e.g. species rediscovery, red list classification, range extension) and how it integrates with ecological research (e.g. ethnobotany, livestock census), citing examples from three biodiversity hotspots in Southern Africa (Namibia and South Africa). Information collected by custodians has helped to prioritise plant species that are in need of conservation attention. Paraecologists have played a key role in supporting the fieldwork of researchers. Various eco-club activities have been undertaken with schools, and a network of eco-club volunteers has been developed

Does functional soil microbial diversity contribute to explain within-site plant beta-diversity in an alpine grassland and a <i>dehesa</i> meadow in Spain?

Questions: Once that the effects of hydrological and chemical soil properties have been accounted for, does soil microbial diversity contribute to explain change in plant community structure (i.e. within-site beta-diversity)? If so, at which spatial scale does microbial diversity operate? Location: La Mina in Moscosa Farm, Salamanca, western Spain (dehesa community) and Laguna Larga in the Urbión Peaks, Soria, central-northern Spain (alpine grassland). Methods: The abundance of vascular plant species, soil gram-negative microbial functional types and soil chemical properties (pH, available phosphorus, and extractable cations) were sampled at both sites, for which hydrological models were available. Redundancy analysis (RDA) was used to partition variation in plant community structure into hydrological, chemical and microbial components. Spatial filters, arranged in scalograms, were used to test for the spatial scales at which plant community structure change. Results: In the case of the dehesa the diversity of soil gram-negative microbes, weakly driven by soil pH, contributed to a small extent (adj-R2 = 2%) and at a relative medium spatial scale to explain change in plant community structure. The abundance of a few dehesa species, both annual (Trifolium dubium, Vulpia bromoides) and perennial (Poa bulbosa, Festuca ampla), was associated with either increasing or decreasing soil microbial diversity. In the alpine meadow the contribution was negligible. Conclusions: Microbial diversity can drive community structure, though in the hierarchy of environmental factors structuring communities it appears to rank lower than other soil factors. Still, microbial diversity appears to promote or restrain individual plant species. This paper aims to encourage future studies to use more comprehensive and insightful techniques to assess microbial diversity and to combine this with statistical approaches such as the one used here

Hydrological niches in terrestrial plant communities: a review

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). 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. 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. 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

Experimental investigation of the origin of fynbos plant community structure after fire

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 moistur

Preparing for an interdisciplinary future: A perspective from early-career researchers

Increasingly, research is moving towards more interdisciplinary endeavours. Effective collaboration between people from different disciplines is necessary to maximise the potential benefits of interdisciplinarity for future research activity. This paper analyses an approach to fostering the skills required for successful cross-disciplinary collaboration from the perspective of an interdisciplinary group of early-career researchers. Our reflection on how specially-designed encounters can help to shape future interdisciplinary research initiatives draws on the discussion of a four-day workshop, a post-event survey, and a review of other experiences. We conclude that interdisciplinary encounters are an effective means to support the development of future interdisciplinary researchers, with a major advantage of this approach being the opportunity for open communication. Depending on the organiser's aim, we distinguish between “cultivation” and “development” encounters. Among the multiple factors that produce successful interdisciplinary encounters, we found that selection of a theme, participants and location need to be tailored to the encounter's particular objectives. We recommend that funding bodies and other members of the research community should take note of the effectiveness of encounters to foster interdisciplinarity and generate space to develop more innovative and high-impact research that delivers solutions to the challenges facing humanity in the future

Climate Change Impacts on Hydrological Niches of Restionaceae Species in Jonkershoek, South Africa

The Restionaceae species of the Fynbos biome is part of the Cape Floristic Kingdom is threatened by urbanization, agricultural expansion, groundwater extraction, and climate change. Therefore, it is necessary to assess and monitor the Restionaceae species under the impact of climate change. South Africa is a semi-arid environment, and hydrological factors are the main variables in the determination of species niches. This study investigates the microclimate at Jonkershoek, and examines the impact of climate change to the plant species distribution, thus creating shifts in the hydrological niche. This study generates its own unique microclimate hydrological datasets for modelling species niche. The Restionaceae species and their hydrological niche at the Jonkershoek study area are assessed under future climate change scenario, at a microclimatic level. It provided evidence regarding the importance of the study to understanding the climate change impacts on hydrological niche and on species richness

Promoting climate-smart sustainable agroforestry to tackle social and environmental challenges: The case of macadamia agroforestry in Malawi

Our current global food system is understood to require a fundamental transformation based on a holistic approach to maintain long-term fertility, healthy biodiverse agroecosystems, and climate-proof/secure livelihoods. Recently, there has been a growing recognition of smallholder farmers’ contributions to addressing key global environmental and social development issues, including poverty, food security, climate change, and sustainable development. One specific approach is agroforestry-based agriculture, in which edible food and commercially important trees are grown on cropland, thereby improving the biodiversity of farming systems, enhancing agricultural productivity, and adding benefits such as nutrition and financial stability, not least climate resilience. In this context, we present lessons learned from an agroforestry system in Malawi that involves smallholder farmer cooperatives interplanting macadamia nut trees with annual crops such as groundnuts, maize, and soybeans. We review holistic advantages such as yield improvement, farmer perceptions, and challenges. We provide insights into what works in designing (Neno Macadami Trust and linkage with finance plan) and draw lessons that can be applied to other comparable programmes worldwide

Farmer preference for macadamia varieties and constraints to production in Malawi

Macadamia nuts constitute a vital component of both nutrition and livelihoods for smallholder producers in Malawi. We conducted a comprehensive mixed-methods study, combining qualitative and quantitative analyses, to explore varietal preferences and production challenges among these farmers. Leveraging cross-sectional data from 144 members of the Highlands Macadamia Cooperative Union Limited, our study underscores several significant findings. Our findings reveal that the majority of smallholder macadamia farmers (62%) are aged over 50, with farming as their primary occupation. Varied preferences are driven by yield-related traits, including high yield potential (38%), nut quality (29%), and extended flowering patterns (15%). Among the macadamia varieties, the top five choices, grown by over half of the farmers, include HAES 660 (18%), 800 (10%), 791 (9%), 816 (8%), and 246 (7%). Additionally, our study identifies five primary constraints faced by smallholder macadamia farmers: insect pests (81%), diseases (34%), limited market access (33%), wind damage (25%), and inadequate agricultural advisory services (17%). Based on these findings, we propose two policy recommendations to enhance smallholder macadamia production and productivity in Malawi. Specifically, we advocate for informed breeding programs that align with farmer preferences to promote greater adoption of macadamia varieties. Additionally, we emphasize the crucial role of the Malawian government in the macadamia value chain, suggesting active participation in providing extension services and marketing support, akin to its support for other cash crops

Factors affecting soil quality among smallholder macadamia farms in Malawi

Declining soil fertility limits smallholder macadamia productivity in Malawi. To reverse this trend, it is essential to apply organic and inorganic fertilisers in an efficient and effective manner. Yet, fertilizer 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 research need/ 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. More than 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 inherent soil characteristics 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

Quantifying soil hydrology to explain the development of vegetation at an ex-arable wetland restoration site

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