29 research outputs found
The development of a classification system for inland aquatic ecosystems in South Africa
A classification system is described that was developed for inland aquatic ecosystems in South Africa, including wetlands. The six-tiered classification system is based on a top-down, hierarchical classification of aquatic ecosystems, following the functionally-oriented hydrogeomorphic (HGM) approach to classification but incorporating structural attributes at the lower levels of the hierarchy. At Level 1, a distinction is made between inland, estuarine and shallow marine systems using the degree of connectivity to the open ocean as the key discriminator. Inland systems are characterised by the complete absence of marine exchange and/or tidal influence. At Level 2, inland systems are grouped according to the most appropriate spatial framework for the particular application. At Level 3, four primary Landscape Units are distinguished (Valley floor, Slope, Plain, Bench) on the basis of the topographic position within which a particular inland aquatic ecosystem is situated, in recognition of the influence that the landscape setting has over hydrological and hydrodynamic processes acting within an aquatic ecosystem. Level 4 identifies HGM Units, defined primarily according to landform, hydrological characteristics and hydrodynamics. The following primary HGM Units (or HGM Types), which represent the main units of analysis for the classification system, are distinguished at Level 4A: (1) River; (2) Floodplain Wetland; (3) Channelled Valley-Bottom Wetland; (4) Unchannelled Valley-Bottom Wetland; (5) Depression; (6) Seep; (7) Wetland Flat. Secondary discriminators are applied at Level 5 to classify the hydrological regime of an HGM Unit, and Descriptors at Level 6 to categorise a range of biophysical attributes. The HGM Unit at Level 4 and the Hydrological Regime at Level 5 together constitute a Functional Unit, which represents the focal point of the classification system. The utility of the classification system is ultimately dependent on the level to which ecosystem units are classified, which is in turn constrained by the type and extent of information available.Keywords: freshwater ecosystems, hydrogeomorphic (HGM) units, inland water ecosystems, wetlands, wetland classification syste
Recommended from our members
Effects of Understory Vegetation Management on Plant Communities in Oil Palm Plantations in Sumatra, Indonesia
Oil palm plantations have expanded rapidly in recent decades, and are causing substantial impacts on tropical habitats and biodiversity. However, owing to its long lifespan (25-30 years), oil palm forms a much more varied and structurally-complex habitat than many other crops. This can include abundant understory vegetation and also epiphytes on palm trunks. However, the diversity of this plantation vegetation has been poorly studied, and there has been little consideration of the impacts of common plantation vegetation management practices on plant communities.
We conducted a long-term vegetation management experiment that forms part of the Biodiversity and Ecosystem Function in Tropical Agriculture (BEFTA) Programme in Riau, Indonesia. We manipulated herbicide and manual cutting regimes within mature oil palm plantations to create three different understory complexity treatments (Reduced, Normal, and Enhanced vegetation) across replicated sets of plots. Plant communities were surveyed before and after experimental understory vegetation treatments began in three different microhabitats: within the middle of the plantation block (core), on the road edge (edge) and on oil palm trunks (trunk). Part of the sampling was also conducted during a drought event.
We recorded 120 plant species, which comprised a mixture of native, non-native, ‘beneficial’, and ‘problem’ species. We found substantial variation in plant communities between edge, core, and trunk microhabitats, indicating high levels of heterogeneity within the plantation. There were significant effects of varying understory treatment within both core and edge microhabitats, but no spillover of impacts into the trunk microhabitat. We also observed substantial impacts of drought on plant communities, with declines in either biomass, percentage cover, or richness seen across core, edge, and trunk microhabitats during low-rainfall periods. Our findings highlight the diversity of plant communities that can be supported within oil palm plantations, and the substantial impacts that management decisions, and also drought, can have on them. Given the role that diverse plant communities can have in supporting species in other groups, this is likely to have a significant impact on the wider plantation biodiversity. We suggest that plantation management strategies give greater consideration to within-plantation understory plant communities and choose more wildlife-friendly options where possible.This work was funded by The Isaac Newton Trust Cambridge, Golden Agri Resources, and the Natural Environment Research Council [grant number NE/P00458X/1]
Recommended from our members
Understory Vegetation in Oil Palm Plantations Promotes Leopard Cat Activity, but Does Not Affect Rats or Rat Damage
The expansion of oil palm (Elaeis guineensis) plantations is a primary cause of land-use change and biodiversity loss in Southeast Asia. This has led to an increasing demand for the development of more sustainable agricultural management practices in plantations, such as Integrated Pest Management. Although populations of carnivorous mammals show declines when forest is converted to oil palm, some species, such as Leopard Cats (Prionailurus bengalensis) have been found to persist. They are often encouraged by plantation managers for their conservation value, and as agents of pest control to manage rat populations. Despite this, little is known about whether they reduce pest rat numbers, or whether plantation management affects how they use the oil palm habitat. This study was based at the Biodiversity and Ecosystem Function in Tropical Agriculture (BEFTA) Programme in mature oil palm plantations in Riau, Sumatra, where there are three management strategies altering understory vegetation structure. We quantified Leopard Cat activity, invasive rat abundance and rat damage using camera traps, live traps, and visual estimates, respectively. We collected data over a 4-year period, before and after the management strategies were applied. We recorded three species of wild mammals (Leopard Cats, Common Palm Civets, and Wild Pig) within the plantations, of which Leopard Cats made up 82% of the total number of observations. We found that Leopard Cat habitat use was higher with increased understory vegetation, but that there was no effect of the vegetation treatments on rat abundance or rat damage. There was also a trend for reduced rat abundance with increased Leopard Cat activity. These results show that management practices can significantly affect Leopard Cat habitat use, with potential benefits for pest control. They also highlight the value of large-scale long-term manipulative experiments for developing more sustainable management practices in oil palm.This work was funded by The Isaac Newton Trust Cambridge, Sinar Mas Agro Resources Technology Research Institute (SMARTRI), and the Natural Environment Research Council [grant number NE/P00458X/1]. AH was funded by the Claire Barnes Studentship from the Department of Zoology, University of Cambridge. Fieldwork was funded by SMARTRI
Recommended from our members
Complexity within an oil palm monoculture: The effects of habitat variability and rainfall on adult dragonfly (Odonata) communities
Recent expansion of oil palm agriculture has resulted in loss of forest habitat and forest-dependent species. However, large numbers of species – particularly insects – can persist within plantations. This study focuses on Odonata (dragonflies and damselflies): a charismatic indicator taxon, and a potentially valuable pest control agent. We surveyed adult Odonata populations biannually over three years within an industrial oil palm plantation in Sumatra, Indonesia. We assessed the effects of rainfall (including an El Niño Southern Oscillation-associated drought), the role of roadside ditches, and the importance of understory vegetation on Odonata populations. To assess the impacts of vegetation we took advantage of a long-term vegetation management experiment that is part of the Biodiversity and Ecosystem Function in Tropical Agriculture (BEFTA) Programme. We found 41 Odonata species, and communities varied between plantation core and roadside edge microhabitats, and between seasons. Abundance was significantly related to rainfall levels four months before surveys, probably indicating the importance of high water levels in roadside ditches for successful larval development. We found no significant effect of the BEFTA understory vegetation treatments on Odonata abundance, and only limited effects on community composition, suggesting that local understory vegetation structure plays a relatively unimportant role in determining communities. Our findings highlight that there are large numbers of Odonata species present within oil palm plantations, and suggest that their abundance could potentially be increased by maintaining or establishing waterbodies. As Odonata are predators, this could bring pest control benefits, in addition to enhancing biodiversity within intensive agricultural landscapes.This work was funded by The Isaac Newton Trust Cambridge, Golden Agri Resources, and the Natural Environment Research Council [grant number NE/P00458X/1]
Recommended from our members
Resilience of ecological functions to drought in an oil palm agroecosystem
Abstract
Oil palm is a major habitat in the tropics. It is highly productive and contributes substantially to the economies of producing countries, but its expansion has caused widespread deforestation, with negative consequences for biodiversity. Such biodiversity losses may have substantial impacts on ecosystem functions within oil palm and resilience of functions to changing rainfall patterns, with impacts on yield. However, although the direct effects of water deficit on yield have been studied, little work has investigated ecosystem processes within plantations or the resilience of functions to changing rainfall. We conducted ecosystem function experiments within mature oil palm at the Biodiversity and Ecosystem Function in Tropical Agriculture (BEFTA) Programme site in Sumatra, Indonesia. We measured rates of leaf litter decomposition, seed removal, mealworm predation, and herbivory at multiple time points spanning the 2015–2016 El Niño - Southern Oscillation (ENSO) event that caused widespread drought within Southeast Asia. We found that mealworm predation, seed removal, and decomposition rates were high, whilst herbivory levels were low, indicating a healthy ecosystem with high levels of pest control and organic matter breakdown. Exclusion tests showed that the presence of invertebrates was associated with higher levels of seed removal and decomposition and the presence of vertebrates with higher predation. All functions were relatively robust to changes in rainfall. Yet, whilst seed removal and herbivory did not alter with rainfall, decomposition and predation showed more complex effects, with levels of both processes increasing with current rainfall levels when rainfall in preceding time periods was low. This suggests that both processes are resilient to change and able to recover following drought. Our results indicate that the ecosystem processes measured within oil palm plantations are healthy and resilient to changing rainfall patterns. This is hopeful and suggests that the crop may be fairly robust to future changes in precipitation.Isaac Newton Trust Cambridge
Sinar Mas Agro Resources and Technology Research Institut
Recommended from our members
Managing Oil Palm Plantations More Sustainably: Large-Scale Experiments Within the Biodiversity and Ecosystem Function in Tropical Agriculture (BEFTA) Programme
Conversion of tropical forest to agriculture results in reduced habitat heterogeneity, and associated declines in biodiversity and ecosystem functions. Management strategies to increase biodiversity in agricultural landscapes have therefore often focused on increasing habitat complexity; however, the large-scale, long-term ecological experiments that are needed to test the effects of these strategies are rare in tropical systems. Oil palm (Elaeis guineensis Jacq.)—one of the most widespread and important tropical crops—offers substantial potential for developing wildlife-friendly management strategies because of its long rotation cycles and tree-like structure. Although there is awareness of the need to increase sustainability, practical options for how best to manage oil palm plantations, for benefits to both the environment and crop productivity, have received little research attention.
In this paper we introduce the Biodiversity and Ecosystem Function in Tropical Agriculture (BEFTA) Programme: a long-term research collaboration between academia and industry in Sumatra, Indonesia. The BEFTA Programme aims to better understand the oil palm agroecosystem and test sustainability strategies. We hypothesise that adjustments to oil palm management could increase structural complexity, stabilize microclimate, and reduce reliance on chemical inputs, thereby helping to improve levels of biodiversity and ecosystem functions. The Programme has established four major components: (1) assessing variability within the plantation under business-as-usual conditions; (2) the BEFTA Understory Vegetation Project, which tests the effects of varying herbicide regimes; (3) the Riparian Ecosystem Restoration in Tropical Agriculture (RERTA) Project, which tests strategies for restoring riparian habitat; and (4) support for additional collaborative projects within the Programme landscape. Across all projects, we are measuring environmental conditions, biodiversity, and ecosystem functions. We also measure oil palm yield and production costs, in order to assess whether suggested sustainability strategies are feasible from an agronomic perspective.
Early results show that oil palm plantation habitat is more variable than might be expected from a monoculture crop, and that everyday vegetation management decisions have significant impacts on habitat structure. The BEFTA Programme highlights the value of large-scale collaborative projects for understanding tropical agricultural systems, and offers a highly valuable experimental set-up for improving our understanding of practices to manage oil palm more sustainably.This work was funded by The Isaac Newton Trust Cambridge, Golden Agri Resources, ICOPE (the International Conference on Oil Palm and the Environment), and the Natural Environment Research Council [grant number NE/P00458X/1]
Citizen science: a new approach to advance ecology, education, and conservation
Citizen science has a long history in the ecological sciences and has made substantial contributions to science, education, and society. Developments in information technology during the last few decades have created new opportunities for citizen science to engage ever larger audiences of volunteers to help address some of ecology’s most pressing issues, such as global environmental change. Using online tools, volunteers can find projects that match their interests and learn the skills and protocols required to develop questions, collect data, submit data, and help process and analyze data online. Citizen science has become increasingly important for its ability to engage large numbers of volunteers to generate observations at scales or resolutions unattainable by individual researchers. As a coupled natural and human approach, citizen science can also help researchers access local knowledge and implement conservation projects that might be impossible otherwise. In Japan, however, the value of citizen science to science and society is still underappreciated. Here we present case studies of citizen science in Japan, the United States, and the United Kingdom, and describe how citizen science is used to tackle key questions in ecology and conservation, including spatial and macro-ecology, management of threatened and invasive species, and monitoring of biodiversity. We also discuss the importance of data quality, volunteer recruitment, program evaluation, and the integration of science and human systems in citizen science projects. Finally, we outline some of the primary challenges facing citizen science and its future.Dr. Janis L. Dickinson was the keynote speaker at the international symposium at the 61th annual meeting of the Ecological Society of Japan. We appreciate the Ministry of Education, Culture, Sports, Science and Technology in Japan for providing grant to Hiromi Kobori (25282044). Tatsuya Amano is financially supported by the European Commission’s Marie Curie International Incoming Fellowship Programme (PIIF-GA-2011- 303221). The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the funding agencies or the Department of the Interior or the US Government.This is the final version of the article. It was first available from Springer via http://dx.doi.org/10.1007/s11284-015-1314-
Leveraging conservation action with open‐source hardware
Data collection by conservation biologists is undergoing radical change, with researchers collaborating across disciplines to create bespoke, low‐cost monitoring equipment from open‐source hardware (OSH). Compared to commercial hardware, OSH dramatically reduces participation costs. Four barriers currently hold back its wide adoption: (1) user inexperience inhibits initial uptake; (2) complex and costly manufacturing/distribution procedures impede global dissemination; (3) lack of creator support results in lapsed projects; and (4) lack of user support degrades continued utility in the field. Here, we propose a framework to address these barriers, illustrating how OSH offers a route to rapid expansion of community‐driven conservation action
AudioMoth: Evaluation of a smart open acoustic device for monitoring biodiversity and the environment
1.The cost, usability and power efficiency of available wildlife monitoring equipment currently inhibits full ground-level coverage of many natural systems. Developments over the last decade in technology, open science, and the sharing economy promise to bring global access to more versatile and more affordable monitoring tools, to improve coverage for conservation researchers and managers. 2.Here we describe the development and proof-of-concept of a low-cost, small-sized and low-energy acoustic detector: ‘AudioMoth’. The device is open-source and programmable, with diverse applications for recording animal calls or human activity at sample rates of up to 384 kHz. We briefly outline two ongoing real-world case studies of large-scale, long-term monitoring for biodiversity and exploitation of natural resources. These studies demonstrate the potential for AudioMoth to enable a substantial shift away from passive continuous recording by individual devices, towards smart detection by networks of devices flooding large and inaccessible ecosystems. 3.The case studies demonstrate one of the smart capabilities of AudioMoth, to trigger event logging on the basis of classification algorithms that identify specific acoustic events. An algorithm to trigger recordings of the New Forest cicada (Cicadetta montana) demonstrates the potential for AudioMoth to vastly improve the spatial and temporal coverage of surveys for the presence of cryptic animals. An algorithm for logging gunshot events has potential to identify a shotgun blast in tropical rainforest at distances of up to 500 m, extending to 1 km with continuous recording. 4.AudioMoth is more energy efficient than currently available passive acoustic monitoring (PAM) devices, giving it considerably greater portability and longevity in the field with smaller batteries. At a build cost of ~US$43 per unit, AudioMoth has potential for varied applications in large-scale, long-term acoustic surveys. With continuing developments in smart, energy-efficient algorithms and diminishing component costs, we are approaching the milestone of local communities being able to afford to remotely monitor their own natural resources.</p