Kevin Li

Dr. Kevin Li

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Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 May 2023 in Nature
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Journal Article
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DZDelphine Clara Zemp
Delphine Clara Zemp
NGNathaly Guerrero-Ramirez
Nathaly Guerrero-Ramirez
FBFabian Brambach
Fabian Brambach
KDKevin Darras
Kevin Darras
IGIngo Grass
Ingo Grass
HKHolger Kreft
Holger Kreft
In the United Nations Decade on Ecosystem Restoration1, large knowledge gaps persist on how to increase biodiversity and ecosystem functioning in cash crop-dominated tropical landscapes2. Here, we present findings from a large-scale, 5-year ecosystem restoration experiment in an oil palm landscape enriched with 52 tree islands, encompassing assessments of ten indicators of biodiversity and 19 indicators of ecosystem functioning. Overall, indicators of biodiversity and ecosystem functioning, as well as multidiversity and ecosystem multifunctionality, were higher in tree islands compared to conventionally managed oil palm. Larger tree islands led to larger gains in multidiversity through changes in vegetation structure. Furthermore, tree enrichment did not decrease landscape-scale oil palm yield. Our results demonstrate that enriching oil palm-dominated landscapes with tree islands is a promising ecological restoration strategy, yet should not replace the protection of remaining forests.

1 August 2019 in Agriculture, Ecosystems & Environment
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Journal Article
Closed access
KLKevin Li
Kevin Li
TTTeja Tscharntke
Teja Tscharntke
BSBarbara Saintes
Barbara Saintes
DBDamayanti Buchori
Damayanti Buchori
IGIngo Grass
Ingo Grass

1 December 2019 in BioScience
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Journal Article
Open access
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JVJohn Vandermeer
John Vandermeer
IAInge Armbrecht
Inge Armbrecht
AMAldo de la Mora
Aldo de la Mora
KEKatherine K Ennis
Katherine K Ennis
GFGordon Fitch
Gordon Fitch
IPIvette Perfecto
Ivette Perfecto
Whether an ecological community is controlled from above or below remains a popular framework that continues generating interesting research questions and takes on especially important meaning in agroecosystems. We describe the regulation from above of three coffee herbivores, a leaf herbivore (the green coffee scale, Coccus viridis), a seed predator (the coffee berry borer, Hypothenemus hampei), and a plant pathogen (the coffee rust disease, caused by Hemelia vastatrix) by various natural enemies, emphasizing the remarkable complexity involved. We emphasize the intersection of this classical question of ecology with the burgeoning field of complex systems, including references to chaos, critical transitions, hysteresis, basin or boundary collision, and spatial self-organization, all aimed at the applied question of pest control in the coffee agroecosystem.

1 May 2016 in Royal Society Open Science
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Journal Article
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KLKevin Li
Kevin Li
JVJohn H. Vandermeer
John H. Vandermeer
IPIvette Perfecto
Ivette Perfecto
Spatial patterns in ecology can be described as reflective of environmental heterogeneity (exogenous), or emergent from dynamic relationships between interacting species (endogenous), but few empirical studies focus on the combination. The spatial distribution of the nests of Azteca sericeasur , a keystone tropical arboreal ant, is thought to form endogenous spatial patterns among the shade trees of a coffee plantation through self-regulating interactions with controlling agents (i.e. natural enemies). Using inhomogeneous point process models, we found evidence for both types of processes in the spatial distribution of A. sericeasur . Each year's nest distribution was determined mainly by a density-dependent relationship with the previous year's lagged nest density; but using a novel application of a Thomas cluster process to account for the effects of nest clustering, we found that nest distribution also correlated significantly with tree density in the later years of the study. This coincided with the initiation of agricultural intensification and tree felling on the coffee farm. The emergence of this significant exogenous effect, along with the changing character of the density-dependent effect of lagged nest density, provides clues to the mechanism behind a unique phenomenon observed in the plot, that of an increase in nest population despite resource limitation in nest sites. Our results have implications in coffee agroecological management, as this system provides important biocontrol ecosystem services. Further research is needed, however, to understand the effective scales at which these relationships occur.

15 May 2023 in Ecological Applications
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Journal Article
Open access
KLKevin Li
Kevin Li
IGIngo Grass
Ingo Grass
DZDelphine Clara Zemp
Delphine Clara Zemp
HLHendrik Lorenz
Hendrik Lorenz
LSLena Sachsenmaier
Lena Sachsenmaier
TTTeja Tscharntke
Teja Tscharntke
As the extent of oil palm (Elaeis guineensis) cultivation has expanded at the expense of tropical rainforests, enriching conventional large‐scale oil palm plantations with native trees has been proposed as a strategy for restoring biodiversity and ecosystem function. However, how tree enrichment affects insect‐mediated ecosystem functions is unknown. We investigated impacts on insect herbivory and pollination in the fourth year of a plantation‐scale, long‐term oil palm biodiversity enrichment experiment in Jambi, Sumatra, Indonesia. Within 48 plots systematically varying in size (25–1600 m2) and planted tree species richness (one to six species), we collected response data on vegetation structure, understory insect abundances, and pollinator and herbivore activity on chili plants (Capsicum annuum), which served as indicators of insect‐mediated ecosystem functions. We examined the independent effects of plot size, tree species richness, and tree identity on these response variables, using the linear model for random partitions design. The experimental treatments were most associated with vegetation structure: tree identity mattered, as the species Peronema canescens strongly decreased (by approximately one standard deviation) both canopy openness and understory vegetation cover; whereas tree richness only decreased understory flower density. Further, the smallest plots had the lowest understory flower density and richness, presumably because of lower light availability and colonization rates, respectively. Enrichment influenced herbivorous insects and natural enemies in the understory to a lesser extent: both groups had higher abundances in plots with two enrichment species planted, possibly because higher associated tree mortality created more habitat, while herbivores decreased with increasing tree species richness, in line with the resource concentration hypothesis. Linking relationships in structural equation models showed that the negative association between P. canescens and understory vegetation cover was mediated through canopy openness. Likewise, canopy openness mediated increases in herbivore and pollinator insect abundances. Higher pollinator visitation increased phytometer yield, while impacts of insect herbivores on yield were not apparent. Our results demonstrate that even at an early stage, different levels of ecological restoration influence insect‐mediated ecosystem functions, mainly through canopy openness. These findings suggest that maintaining some canopy gaps while enrichment plots develop may be beneficial for increasing habitat heterogeneity and insect‐mediated ecosystem functions.

1 May 2012 in Neurological Research
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Journal Article
Closed access
YYYu Yuan
Yu Yuan
CPChangya Peng
Changya Peng
KLKevin Li
Kevin Li
MHMohammed Hussain
Mohammed Hussain
CSChaitanya Sikharam
Chaitanya Sikharam
Yuchuan DingYuchuan Ding
Yuchuan Ding
Acute administration of ethanol is associated with neuroprotection in rat with transient cerebral ischemia. To investigate the molecular mechanism of ethanol-induced neuroprotection, we determined the effect of ethanol on expression levels of apoptotic proteins, including caspase-3, Bcl-2-associated X protein (Bax), and apoptosis-inducing factor (AIF). To assess overall cell viability following ethanol treatment, ADP/ATP ratio was measured. Brain slice cultures were prepared using postnatal 10-day-old Sprage-Dawley rats. Brain slices were divided into control and hypoxia groups. Hypoxia groups include a non-treatment group and three treatment groups (10, 30, or 90 mM ethanol). Levels of caspase-3, Bax, and AIF were determined by western blot. ADP/ATP ratio was assessed using ADP/ATP assay kit. Ethanol administration reduced ADP/ATP ratio in all three treatment groups (10, 30, and 90 mM). A reduction in caspase-3, BAX, and AIF expression was observed with all three treatment groups in conjunction with decreased ADP/ATP levels. The three treatment groups showed similar levels of reduction in ADP/ATP ratio and apoptotic protein expression. Ethanol-induced neuroprotection involves inhibition of apoptotic pathways, including Bax, caspase-3, and AIF. Dose range of 10-90 mM ethanol provides similar level of protection compared to 10 mM ethanol.