Dr Jake Bicknell
Dr Jake Bicknell joined DICE in 2011 as a PhD student and graduate teaching assistant. He is now a Postdoctoral Research Associate working on the project entitled ‘Biodiversity and Ecosystem Processes in Human-Modified Tropical Forests’. Previously Jake worked on ‘Restoration efforts required for achieving the objectives of the Birds and Habitats Directives’, and elsewhere has worked for the Royal Society for the Protection of Birds (RSPB), Operation Wallacea and the Iwokrama International Center for Rainforest Conservation and Development in Guyana.
Dr Bicknell is a conservation scientist, broadly interested in conservation throughout the globe and across taxonomic groups. He works alongside Professor Zoe Davies and Dr Matt Struebig on the project 'Biodiversity and Ecosystem Processes in Human-Modified Tropical Forests.' This work is aimed at understanding the relationships between biodiversity and biogeochemical processes, and the impact of land-use policies on delivering both ecosystem service provision and conserving biodiversity in human-modified tropical forests. The research draws on extensive data from the Stability of Altered Forest Ecosystems (SAFE) project in Sabah (Malaysian Borneo), in a landscape comprising unlogged and logged forests, as well as oil palm plantations. The project is part of NERC’s Human-modified Tropical Forests research programme within the LOMBOK consortium.
Dr Bicknell's PhD focused on human-modified tropical forests, exploring the consequences of improving timber harvest techniques for biodiversity. Jake conducted field research in Guyana combined with meta-analyses to appraise a technique called Reduced-Impact Logging. The findings provide strong evidence that widely improving timber harvest practices will lead to substantially increased conservation values across the 4 million km2 of tropical forest (an area larger than India) that are allocated to timber production.
Dr Bicknell has also previously worked as a Postdoctoral Research Associate on a project entitled ‘Restoration efforts required for achieving the objectives of the Birds and Habitats Directives’. This work was funded by the European Commission and was aimed at understanding the restoration measures needed to accomplish the Nature Directives. The findings contributed directly to the European Commission’s appraisal of the Directives and focused on understanding what habitats, species, regions or countries require increased efforts, also identifying best practices regarding restoration across the European Union.
Dr Bicknell is interested in many other aspects of conservation science, including landscape-scale land-use planning for conservation. Jake recently worked alongside stakeholders and the Government of Guyana to develop a holistic approach to land-use planning in Guyana using systematic conservation planning.
- DI508: Data Analysis for Conservation Biologists
Dr Bicknell is available to provide commentary on issues related to land-use change in tropical forests, particularly regarding forestry and mining, and the conservation of biodiversity.
Bicknell, J. et al. (2017). Designing protected area networks that translate international conservation commitments into national action. Biological Conservation [Online] 214:168-175. Available at: http://dx.doi.org/10.1016/j.biocon.2017.08.024.Most countries have committed to protect 17% of their terrestrial area by 2020 through Aichi Target 11 of the
Convention on Biological Diversity, with a focus on protecting areas of particular importance for biodiversity.
This means national-scale spatial conservation prioritisations are needed to help meet this target and guide
broader conservation and land-use policy development. However, to ensure these assessments are adopted by
policy makers, they must also consider national priorities. This situation is exemplified by Guyana, a corner of
Amazonia that couples high biodiversity with low economic development. In recent years activities that threaten
biodiversity conservation have increased, and consequently, protected areas are evermore critical to achieving
the Aichi targets. Here we undertake a cost-effective approach to protected area planning in Guyana that accounts
for in-country conditions. To do this we conducted a stakeholder-led spatial conservation prioritization
based on meeting targets for 17 vegetation types and 329 vertebrate species, while minimising opportunity costs
for forestry, mining, agriculture and urbanisation. Our analysis identifies 3 million ha of priority areas for
conservation, helping inform government plans to double the current protected area network from 8.5 to 17%.
As part of this, we also develop a new technique to prioritise engagement with local communities whose lands
are identified as important to conservation. Our study both provides a scientifically robust, politically acceptable protected area expansion strategy for Guyana, and illustrates the importance of conservation planning at the country-scale
to translate international commitments into national action.
Hudson, L. et al. (2016). The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project. Ecology and Evolution [Online] 7:145-188. Available at: https://doi.org/10.1002/ece3.2579.The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.
Rivett, S., Bicknell, J. and Davies, Z. (2016). Effect of reduced-impact logging on seedling recruitment in a neotropical forest. Forest Ecology and Management [Online] 367:71-79. Available at: http://dx.doi.org/10.1016/j.foreco.2016.02.022.Seedling growth and survival are critical for tropical rainforest regeneration. Alterations to natural disturbance regimes, such as those brought about by logging, have the potential to shift relative species abundances and the community composition of forests, resulting in population declines for commercially valuable species. Timber operations therefore need to minimise such changes if long-term sustainability is to be achieved within the industry. Reduced-impact logging (RIL) has been promoted widely as an alternative management strategy to conventional selective logging, as it employs practices that decrease the negative impacts of logging within forests. However, the long-term sustainability of RIL, including the influence it has on the regeneration of species targeted for timber extraction, is still uncertain. Here we undertake a comparative study in Iwokrama forest, Guyana, examining seedling densities of four commercially valuable and two pioneer tree species in unlogged, 1.5 years and 4.5 years postharvest forest plots to ascertain how seedling regeneration is effected by RIL. We find that RIL had either a neutral or positive impact on the density of seedlings of timber species when compared to unlogged forest, with pioneer species densities remaining unaffected. We conclude that the forestry practices associated with RIL have little effect on the natural regeneration rates of key commercially valuable tree species in logged neotropical forests.
Bicknell, J., Struebig, M. and Davies, Z. (2015). Reconciling timber extraction with biodiversity conservation in tropical forests using reduced-impact logging. Journal of Applied Ecology [Online] 52:379-388. Available at: http://dx.doi.org/10.1111/1365-2664.12391.Over 20% of the world's tropical forests have been selectively logged, and large expanses are allocated for future timber extraction. Reduced-impact logging (RIL) is being promoted as best practice forestry that increases sustainability and lowers CO2 emissions from logging, by reducing collateral damage associated with timber extraction. RIL is also expected to minimize the impacts of selective logging on biodiversity, although this is yet to be thoroughly tested.
We undertake the most comprehensive study to date to investigate the biodiversity impacts of RIL across multiple taxonomic groups. We quantified birds, bats and large mammal assemblage structures, using a before-after control-impact (BACI) design across 20 sample sites over a 5-year period. Faunal surveys utilized point counts, mist nets and line transects and yielded >250 species. We examined assemblage responses to logging, as well as partitions of feeding guild and strata (understorey vs. canopy), and then tested for relationships with logging intensity to assess the primary determinants of community composition.
Community analysis revealed little effect of RIL on overall assemblages, as structure and composition were similar before and after logging, and between logging and control sites. Variation in bird assemblages was explained by natural rates of change over time, and not logging intensity. However, when partitioned by feeding guild and strata, the frugivorous and canopy bird ensembles changed as a result of RIL, although the latter was also associated with change over time. Bats exhibited variable changes post-logging that were not related to logging, whereas large mammals showed no change at all.
Indicator species analysis and correlations with logging intensities revealed that some species exhibited idiosyncratic responses to RIL, whilst abundance change of most others was associated with time.
Synthesis and applications. Our study demonstrates the relatively benign effect of reduced-impact logging (RIL) on birds, bats and large mammals in a neotropical forest context, and therefore, we propose that forest managers should improve timber extraction techniques more widely. If RIL is extensively adopted, forestry concessions could represent sizeable and important additions to the global conservation estate – over 4 million km2.
Bicknell, J. et al. (2015). Saving logged tropical forests: closing roads will bring immediate benefits. Frontiers in Ecology and the Environment [Online] 13:73-74. Available at: http://dx.doi.org/10.1890/15.WB.001.
Horsley, T. et al. (2015). Seed dispersal by frugivorous bats in Central Guyana and a description of previously unknown plant-animal interactions. Acta Chiropterologica 17:331-336.Species of bats in the subfamilies Stenodermatinae and Carolliinae are primarily frugivores, and through the ingestion of fruit and
defecation of seeds, they play a crucial role in their environment through the dispersal of early successional and pioneer plants contributing to reforestation. These ecosystem services provided by frugivorous bats are becoming more critical with time, as anthropogenic habitat destruction continues to rise. The objective of this study was to survey the plant species dispersed by frugivorous bats in a tropical rainforest in Guyana. Fecal samples were taken from captured frugivorous bats and stomach contents were taken from a representative collection. The four most common bats were Artibeus planirostris, A. obscurus, A. lituratus, and Carollia perspicillata, which accounted for 67% of total captures in mist nets set in the forest understory. Twenty plant species were identified in fecal and stomach content samples with the most abundant (Ficus nymphaeifolia, Piper bartlingianum, Cecropia latiloba, and C. sciadophylla) accounting for 60% of the total. Cecropia latiloba, which is an early colonizer of floodplains throughout the Guiana Shield and Amazon River Basin was previously unknown to be bat dispersed. Seven plant species were documented as being dispersed by nine bat species for the first time. These results enhance our understanding of seed dispersal by Neotropical bats, specifically by revealing previously unknown bat/plant relationships.
Bicknell, J. et al. (2014). Dung beetles as indicators for rapid impact assessments: evaluating best practice forestry in the neotropics. Ecological Indicators [Online] 43:154-161. Available at: http://dx.doi.org/10.1016/j.ecolind.2014.02.030.Dung beetles (Scarabaeidae: Scarabaeinae) are sensitive to habitat perturbations and are easily studied, making them an ideal taxonomic group with which to evaluate the effects of low-intensity anthropogenic disturbances such as Reduced-Impact Logging. Here we examine the effect of a certified Reduced-Impact Logging operation on dung beetles, and demonstrate their suitability for use in rapid ecological impact studies. We sampled dung beetle assemblages, environmental variables and timber extraction rates across four treatment groups in closed canopy and canopy gaps in logged and unlogged forest in Guyana. Community analysis revealed that logged forest supported a more uniform dung beetle assemblage compared to unlogged forest. Differences in assemblage structure were driven by dissimilarity between closed canopy treatments, as plots in artificial and natural canopy gaps supported comparable assemblages. Indicator analyses were conducted across treatments, using a new approach (CLAM) and two well-established methods (IndVal, SIMPER). Two species respectively were classified as indicators of logged (Hansreia affinis and Eurysternus caribaeus) and unlogged forest (Canthidium aff. centrale and Deltochilum (Calhyboma) carinatum). BIO-ENV analysis demonstrated that tree extraction intensity, bare ground cover, and ground cover by leaf material were key factors influencing dung beetle assemblages. Despite the relatively low-impact of Reduced-Impact Logging reported by previous studies, we find that dung beetles are sensitive to even small changes in environmental conditions as a result of this form of anthropogenic disturbance. As dung beetles are a highly responsive taxonomic group, we illustrate that they represent a valuable taxon that can be used to critically evaluate best practice forestry operations and other disturbance activities, particularly in time constrained studies (e.g., rapid monitoring and environmental impact assessments). However, we recommend the use of multiple indicator analyses to monitor potential changes in assemblage composition, due to a lack of congruence between methods.
Bicknell, J. et al. (2014). Improved timber harvest techniques maintain biodiversity in tropical forests. Current Biology [Online] 24:1119-1120. Available at: http://dx.doi.org/10.1016/j.cub.2014.10.067.Tropical forests are selectively logged at 20 times the rate at which they are cleared, and at least a fifth have already been disturbed in this way. In a recent pan-tropical assessment, Burivalova et al. demonstrate the importance of logging intensity as a driver of biodiversity decline in timber estates. Their analyses reveal that species richness of some taxa could decline by 50% at harvest intensities of 38 m3 ha-1. However, they did not consider the extraction techniques that lead to these intensities. Here, we conduct a complementary meta-analysis of assemblage responses to differing logging practices: conventional logging and reduced-impact logging. We show that biodiversity impacts are markedly less severe in forests that utilise reduced-impact logging, compared to those using conventional methods. While supporting the initial findings of Burivalova et al., we go on to demonstrate that best practice forestry techniques curtail the effects of timber extraction regardless of intensity. Therefore, harvest intensities are not always indicative of actual disturbance levels resulting from logging. Accordingly, forest managers and conservationists should advocate practices that offer reduced collateral damage through best practice extraction methods, such as those used in reduced-impact logging. Large-scale implementation of this approach would lead to improved conservation values in the 4 million km2 of tropical forests that are earmarked for timber extraction.
Dallimer, M. et al. (2012). The importance of novel and agricultural habitats for the avifauna of an oceanic island. Journal for Nature Conservation [Online] 20:191-199. Available at: http://dx.doi.org/10.1016/j.jnc.2012.04.001.Conservation management can no longer rely on protecting pristine habitats, but must consider the
wider landscape. This is especially true on oceanic islands where endemic species are believed to be
particularly susceptible to the extinction risks that accompany land conversion. Despite this, there is a
paucity of studies examining how endemic communities on oceanic islands may be distributed across
such human-modified habitats. Taking Príncipe Island in West Africa as a case study, we investigate how
avian communities vary across the habitats (primary forest, secondary forest, agricultural areas) of this
globally important centre of endemism. Here, recent policy reforms aimed at poverty alleviation and
increased food production are rapidly altering the current land-use mosaic. Across all habitats, 27 bird
species were encountered. Survey points in secondary forest and agricultural areas were, on average,
more diverse and held higher overall abundances of birds than those within primary forest. This was
true for both the entire avian assemblage and the endemic species alone. Nevertheless, two IUCN-listed
species were restricted to primary forest, and many other endemics occurred at higher densities within
this habitat. We demonstrate that agricultural areas and novel habitats, such as secondary forest, can
hold high abundances of endemic species and thus have the potential to act as a resource for biodiversity
conservation. A double-stranded approach to conservation is therefore required that both protects the
integrity of the primary forest and controls the rapid changes in agricultural land-use to ensure that it
continues to support a large component of the endemic avifauna.
Bicknell, J. and Peres, C. (2010). Vertebrate population responses to reduced-impact logging in a neotropical forest. Forest Ecology and Management [Online] 259:2267-2275. Available at: http://dx.doi.org/10.1016/j.foreco.2010.02.027.Vertebrate population densities were quantified in lowland central Guyana using line-transect censuses at three forest sites subjected to reduced-impact logging (RIL), and three adjacent unlogged sites. We censused a range of forest vertebrate species including large canopy-dwelling and terrestrial birds, three primates, one rodent and one tortoise. Two 4 km transects at each site were repeatedly surveyed during the wet season of 2008 to derive population density estimates on the basis of a cumulative survey effort of 416 km. RIL had ended within 16 months, and sites had been subjected to a mean extraction rate of 3.9 m3 ha−1, equivalent to only 1.1 trees ha−1. Three of the 15 vertebrate species examined here exhibited significantly different abundances at forest RIL sites, two of which were negative. Large frugivores such as primates were less abundant in sites subject to RIL, whereas smaller frugivores, granivores, folivores and insectivores were more common in logged sites. We are unable to reliably distinguish between responses of different taxonomic groups, since robust abundance metrics could only be estimated for four mammal species. Despite this, species traits including dietary guild, body mass, home range size and vertical stratification of forest use are used to explain varying responses. Our findings suggest that responsible reduced-impact logging practices in neotropical forests can be considered as a relatively benign form of forest management that can coexist with the requirements of both local economies and biodiversity conservation. However, our study sites experienced comparably low extraction rates, and detrimental effects such as hunting were low. Our results therefore provide an opportunity to scrutinise the effects of best practice logging systems, though do not necessarily represent typical circumstances across tropical forests.
Bicknell, J. and Chin, C. (2007). Aquarium fisheries as a non-timber forest product: experiences from conservation through community development in North Rupununi District, Guyana. Conservation Evidence [Online] 4:94-98. Available at: http://www.conservationevidence.com/individual-study/2269.Deforestation is one of the major global conservation issues. Solutions are being sought to tackle this ongoing
forest loss, including establishment of initiatives to provide new sources of income for local communities that
promote the sustainable use of forests in the interest of biodiversity conservation. One such project ‘Iwokrama’,
demonstrates how tropical forests and associated habitats can be sustainably used. In the central Guyana wetlands of the Rupununi, illegal fishing of arapaima Arapaima gigas, had led to a huge
reduction in its numbers. Iwokrama responded by initiating the Arapaima Management Plan in 2002. This
highlighted the need for another source of local income from fisheries, and a business that undertakes sustainable harvest
of fish for the aquarium trade was developed. Harvesting of a few selected fish species is carried-out by
members of the local community who are paid a daily wage. Fishing methods target individual species to avoid
incidental by-catch. Four species are primarily caught as they are numerous in the Rupununi and are of high trade
value. To ensure ecological and economical sustainability, catch per unit effort is monitored; where this begins to
drop for any given species, harvesting is suspended and the population is allowed to recover before harvesting
resumes. The project has developed into a self-sustaining business, managed by the community themselves. During
2005, the project reached financial sustainability with current profits of over US$3,000 feeding back into local
Watkins, G. et al. (2005). The fish fauna of the Iwokrama Forest. Proceedings of the Academy of Natural Sciences of Philadelphia [Online] 154:39-53. Available at: http://www.jstor.org/discover/10.2307/4065124?uid=3738032&uid=2134&uid=2&uid=70&uid=4&sid=21106200596831.Fishes were collected from the rivers in and around the Iwokrama Forest during January-February and November-December 1997. Four hundred species of fish were recorded from forty families in ten orders. Many of these fishes are newly recorded from Guyana and several are thought to be endemic. The number of species recorded for the area is surprising given the low level of effort and suggests that this area may be particularly important from a fish diversity perspective. This paper focuses on species of particular interest from a management perspective including those considered economically important, rare or endangered. The paper is also the basis for developing fisheries management systems in the Iwokrama Forest and Rupununi Wetlands.