BACKGROUND: The shift of species distributions is directly correlated to climatic factors, such as temperature and precipitation regimes. However, the underlying mechanisms that shift species distribution are unknown. More importantly, current modeling practice without understanding of the mechanisms could lead to significant bias on prediction of species distribution.
We used extensive long-term forest inventory data from four mountainous areas in eastern China (39,553 individuals in 481 permanent inventory plots), to investigate species range shifts over the past 25 years (1989~2014). (See figs on the right)
We used extensive long-term forest inventory data from four mountainous areas in eastern China (39,553 individuals in 481 permanent inventory plots), to investigate species range shifts over the past 25 years (1989~2014). (See figs on the right)
This is an international project, including scientist from the US, Canada, China, Australia and Turkey. Main collaborators: Lu Zhai (Oklahoma State University), Ken Feeley (University of Miami), Michelle Afkhami (University of Miami).
We are looking for students to join us, contact Bo Zhang ([email protected]) or Lu Zhai ([email protected])
We are looking for students to join us, contact Bo Zhang ([email protected]) or Lu Zhai ([email protected])
3. THE ROLE OF CLIMATE AND OTHER FACTORS IN DRIVING SPECIES SHIFTS IN ELEVATIONAL DISTRIBUTIONS.
1. Project on "understanding the impact of biological control on Melaleuca (Top invasion in FL)
Background:
Melaleuca quinquenervia (pine-bark tree) is an invasive non-native tree that has spread over wide areas of the freshwater ecosystems of southern Florida. The effect of the Melaleuca snout beetle (Bio-control) has been especially effective in decreasing allocation of resources to growth and reproduction, such that Melaleuca has lost its competitive advantage. See pictures below, before and after application of biocontrol.
1996-note very very dense melaleuca forest at the same site. Photo from Dr. Min B. Rayamajhi
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2007.1- open canopy, some newly migrated species under melaleuca canopy, few clumps of sawgrass, most composites like Baccharis species. Photo from Dr. Min B. Rayamajhi
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2007.2- Note fallen trees due to defoliation, dieback, shrunken root mass- open canopy, migration of new species under melaleuca canopy. Photo from Dr. Min B. Rayamajhi
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This work is collaborated with folks in USDA invasive plants laboratory, especially Dr. Min B. Rayamajhi, Dr. Dan Botkin.
This work is funded by USGS's Greater Everglades Priority Ecosystem Science funding
This work is funded by USGS's Greater Everglades Priority Ecosystem Science funding
The goal of this study is to understand the plant community changes that occurred with the introduction of Melaleuca and the changes that are now occurring in Melaleuca-dominated areas with the introduction of bio-control, as well as to project future changes that might be expected over the next decades.
Main results:
Computer simulations show melaleuca invasion leads to decreases in density and basal area of native species, but herbivory would effectively control melaleuca to low levels, resulting in a recovery of native species. |
2013 note more species diversity, such as sawgrass, persia, Ilex recoved in the field. Photo from Dr. Min B. Rayamajhi
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Relevant Presentation:
Oct 2016 – 10th INTECOL international Wetlands Conference, Changshu, China.
May 2016 - The international Society for Ecological Modelling Global Conference, Baltimore, Maryland, USA.
Apr 2016 – National Conference on Ecosystem Restoration (NCER), Coral Springs, FL,USA
Nov 2015 – BIL 149 Guest Speaker, Department of Biology, University of Miami.
Aug 2015 - 100th Ecological Society of America Annual meeting, Baltimore, Maryland.
Apr 2015 - Greater Everglades Ecosystem Restoration (GEER), Coral Springs, FL, USA.
Relevant publications:
USGS_Wetlands: New modeling study suggests introduced insect herbivores could help control the invasive tree melaleuca in long-term
Oct 2016 – 10th INTECOL international Wetlands Conference, Changshu, China.
May 2016 - The international Society for Ecological Modelling Global Conference, Baltimore, Maryland, USA.
Apr 2016 – National Conference on Ecosystem Restoration (NCER), Coral Springs, FL,USA
Nov 2015 – BIL 149 Guest Speaker, Department of Biology, University of Miami.
Aug 2015 - 100th Ecological Society of America Annual meeting, Baltimore, Maryland.
Apr 2015 - Greater Everglades Ecosystem Restoration (GEER), Coral Springs, FL, USA.
Relevant publications:
- Zhang, B., D. L. DeAngelis, M. B. Rayamajhi, D. Botkin. In press Projecting the effects of biocontrol on Melaleucaquinquenervia in southern Florida using individual-based modeling. “Landscape Ecology”. DOI: 10.1007/s10980-017-0519-6
USGS_Wetlands: New modeling study suggests introduced insect herbivores could help control the invasive tree melaleuca in long-term
https://pubs.er.usgs.gov/publication/70187126
Part II - Plant Compensation and the Effects of Biocontrol Herbivory an Invasive Plant
2016 - 2017
This work is collaborated with folks in USDA invasive plants laboratory, Dr.Shu Ju
This work is funded by USGS's Greater Everglades Priority Ecosystem Science funding
This work is funded by USGS's Greater Everglades Priority Ecosystem Science funding
Schematic of model for allocation of carbon and for nutrient cycling. This model is based on a model developed by DeAngelis et al. (2012), which was based on the earlier G'DAY model of Comins and Mcmurtie (1993).
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The main objective of this study is to use a nutrient and carbon allocation model to simulate and theoretically understand the process of how Melaleuca should optimally adapt its strategy of carbon and nutrient allocation in response to the impact of biological control.
I used a model (see Schematic figure on the left) to understand: 1. how Melaleuca should optimally respond to biological control, altering its allocations of nutrient and carbon to compensatory foliage production. 2. The effects of different biological control types, density and soil type on Melaleuca reproduction and growth. |
Relevant publications:
1. Zhang, B., X. Liu, D. L. DeAngelis, L. Zhai, M. B. Rayamajhi, S. Ju. Plant Compensation and the Effects of Biocontrol Herbivory an Invasive Plant. In press Biological Control
1. Zhang, B., X. Liu, D. L. DeAngelis, L. Zhai, M. B. Rayamajhi, S. Ju. Plant Compensation and the Effects of Biocontrol Herbivory an Invasive Plant. In press Biological Control
2. Project on "Is it possible to have larger total population than carrying capacity?"
Collaborated with Dr. Don DeAngelis, Dr. Weiming Ni and graduate student Liu Xin.
This work is funded by J. Gerry Curtis Plant Sciences Scholarships
This work is funded by J. Gerry Curtis Plant Sciences Scholarships
I am interested in the effects of spatial heterogeneity and diffusion on a plant population also. DeAngelis and Zhang 2014 developed a patch model to test a mathematics theory from Dr. Weiming Ni (University of Minnesota) and Dr.Yuan Lou (Ohio States University) that heterogeneous resource conditions with diffusion will result in a larger population biomass than carrying capacity for one species.
I further tested our simulation results by setting up an experiment, using a fast-growing plant species (Duckweed). The results from the experiment proved our simulation results (Zhang et al, 2015).
However, this theory holds only when the maximum growth rate (r) and carrying capacity (K) are positively correlated.
(See Current research)
Relevant Presentation:
Aug 2014 - Bernoulli Workshop on Dispersal in heterogeneous environment, Lausanne, Switzerland.
Jan 2014 -Graduate Students Symposium, Department of Biology, University of Miami.
Relevant Publications:
1. . DeAngelis, D.*, and B. Zhang*. 2014. Effects of Population Dispersal in a Non-Uniform Environment Individual Dynamics and Competition: A Patch Model Approach. Invited paper in Journal discrete and Continuous Dynamical System – B 19: 3087-3104.
2. Zhang, B. Liu, X., DeAngelis , D.L., Ni, W., Wang , G. Geoff. 2015. Effects of dispersal on total biomass in a patchy, heterogeneous system: Analysis and experiment, Mathematical Biosciences 264: 54-62. doi: 10.1016/j.mbs.2015.03.005 This work was published with undergraduate research assistants.
3. DeAngelis, D., W. Ni, and B. Zhang. 2016. Dispersal and spatial heterogeneity: single species. The Journal of Mathematical Biology 72: 239-254. doi 10.1007/s00285-015-0879-y.
4. DeAngelis, D., W. Ni, and B. Zhang. 2016. Effects of Diffusion on Total Biomass in Heterogeneous Continuous and Discrete-Patch Systems. Theoretical Ecology doi 10.1007/s12080-016-0302-3.
I further tested our simulation results by setting up an experiment, using a fast-growing plant species (Duckweed). The results from the experiment proved our simulation results (Zhang et al, 2015).
However, this theory holds only when the maximum growth rate (r) and carrying capacity (K) are positively correlated.
(See Current research)
Relevant Presentation:
Aug 2014 - Bernoulli Workshop on Dispersal in heterogeneous environment, Lausanne, Switzerland.
Jan 2014 -Graduate Students Symposium, Department of Biology, University of Miami.
Relevant Publications:
1. . DeAngelis, D.*, and B. Zhang*. 2014. Effects of Population Dispersal in a Non-Uniform Environment Individual Dynamics and Competition: A Patch Model Approach. Invited paper in Journal discrete and Continuous Dynamical System – B 19: 3087-3104.
2. Zhang, B. Liu, X., DeAngelis , D.L., Ni, W., Wang , G. Geoff. 2015. Effects of dispersal on total biomass in a patchy, heterogeneous system: Analysis and experiment, Mathematical Biosciences 264: 54-62. doi: 10.1016/j.mbs.2015.03.005 This work was published with undergraduate research assistants.
3. DeAngelis, D., W. Ni, and B. Zhang. 2016. Dispersal and spatial heterogeneity: single species. The Journal of Mathematical Biology 72: 239-254. doi 10.1007/s00285-015-0879-y.
4. DeAngelis, D., W. Ni, and B. Zhang. 2016. Effects of Diffusion on Total Biomass in Heterogeneous Continuous and Discrete-Patch Systems. Theoretical Ecology doi 10.1007/s12080-016-0302-3.
Part II - Carrying capacity in a heterogeneous environment with habitat connectivity
2015 - 2017
Collaborated with Dr. Don DeAngelis, Dr. David Van Dyken, Dr.Wei Ming Ni, Alex Kula and undergraduate student Arrix Ryce.
This work is funded by Graduate Student Award to Promote Interdisciplinary Research in Biology from University of Miami
This work is funded by Graduate Student Award to Promote Interdisciplinary Research in Biology from University of Miami
I am collaborating with Dr. David Van Dyken (University of Miami) and Alex Kula (graduate student) to study the carrying capacity in both heterogeneous and homogeneous environments, with yeast.
We make 3 major conclusions:
1) The randomly diffusing population could reach a significantly higher total population than the non-diffusing population in a heterogeneous environment.
2) The r-K relationships determined whether a diffusing population could exceed in size the sum of the local carrying capacities in heterogeneous environment.
3) The diffusing population in the heterogeneous environment did not reach the size of the population supported by the same nutrient input levels homogeneously distributed in space.
The significance of this study:
This work represents a unique melding of rigorous mathematical theory and empirical validation, with broad implications for our understanding of a fundamental ecological concept - carrying capacity.
This work will help us to further understand what we found in Zhang et al, 2015. (See previous research)
We make 3 major conclusions:
1) The randomly diffusing population could reach a significantly higher total population than the non-diffusing population in a heterogeneous environment.
2) The r-K relationships determined whether a diffusing population could exceed in size the sum of the local carrying capacities in heterogeneous environment.
3) The diffusing population in the heterogeneous environment did not reach the size of the population supported by the same nutrient input levels homogeneously distributed in space.
The significance of this study:
This work represents a unique melding of rigorous mathematical theory and empirical validation, with broad implications for our understanding of a fundamental ecological concept - carrying capacity.
This work will help us to further understand what we found in Zhang et al, 2015. (See previous research)
This is the Biomek FXP (Beckman Coulter) liquid handling robot we used to conduct the dispersal (diffusion) process in the project!
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We are having two young scientists joining us CAREFULLY using our robot!
Alex Kula is teaching Francesca |
Relevant publications:
1. Zhang, B†, A. Kula†, K.M.L. Mack, L. Zhai, A.L. Ryce1*, W. Ni, D.L. DeAngelis, J. D. Van Dyken. 2017. Carrying capacity in a heterogeneous environment with habitat connection. Ecology Letters 20: 1118-1128.
2. Van Dyken, J. D., and B. Zhang. Carrying capacity of a spatially-structured population: disentangling the effects of dispersal, growth parameters, habitat heterogeneity and habitat clustering. Journal of Theoretical Biology in press.
1. Zhang, B†, A. Kula†, K.M.L. Mack, L. Zhai, A.L. Ryce1*, W. Ni, D.L. DeAngelis, J. D. Van Dyken. 2017. Carrying capacity in a heterogeneous environment with habitat connection. Ecology Letters 20: 1118-1128.
2. Van Dyken, J. D., and B. Zhang. Carrying capacity of a spatially-structured population: disentangling the effects of dispersal, growth parameters, habitat heterogeneity and habitat clustering. Journal of Theoretical Biology in press.
Previous work:
This is my first research study, which was started in 2007.
The objective of this study is to test the importance of soil characteristics acting as environmental filters on multi-dimensional traits, and thus to understand the community assembly and plant distribution at local scales.
This is my first research study, which was started in 2007.
The objective of this study is to test the importance of soil characteristics acting as environmental filters on multi-dimensional traits, and thus to understand the community assembly and plant distribution at local scales.