Spatial Interaction Ecology
The research group Spatial Interaction Ecology strives to understand how human mediated environmental changes are influencing plant population dynamics, plant-animal interactions and community patterns at multiple spatial scales. In particular, we focus on the causes and consequences of exotic plant invasions, the role of human perturbations on plant-pollinator interactions and pollen limitation, the restoration of degraded habitats, and forest community dynamics.
Our research is funded by the HGF/Helmholtz Recruitment Initiative and the Alexander von Humboldt Professorship.

Causes and consequences of exotic plant invasions
Photo: T. Knight
Why are some exotic plant species able to become dominant in a community while others remain minor constituents? To date, research presents mixed and contradictory results of the relationship between phylogenetic novelty and invasiveness. We aim to resolve some of this variation with a synthetic approach that explicitly considers spatial scale, environmental gradients and stage of invasion. We conduct field experiments that examine multiple mechanisms of invasion and their interactions on exotic plant population dynamics.
In addition, we are synthesizing the effects that natural enemy introductions have on the fitness and population dynamics of exotic weeds.
Projects:
- Community assembly and macroecology of islands
- Role of functional traits in explaining highly invaded Hawaiian ecosystems
- Synthesis of biocontrol agent effects on focal and non-target plants
Pollination Ecology
Photo: C. Müller
Recent global reports such as the IPBES have documented that pollinators are declining in abundance and diversity at local, regional, and global spatial scales due to human changes to the landscapes. How will these pollinator declines change the structure of plant-pollinator interactions and the function of pollination?
We collect plant-pollinator network data and conduct pollination experiments in grassland ecosystems along elevation, latitudinal and land use gradients. We have developed collaborations in understudied regions of Europe that have high densities of traditionally managed meadows. We use hands-on summer schools to grow our database while training the next generation of pollination ecologists. We synthesize the causes and consequence of pollen limitation for plant species. We examine the history of science for this rapidly changing field of study.
Projects:
- Plant-pollinator networks in European meadows
- History of the field of pollination ecology
- Meta-analysis of pollen limitation
- Changes in plant-pollinator networks across long time intervals
- Plant-pollinator networks in agroecosystems
-
Plant-pollinator networks in the Arctic
Visit our current exhibition on pollination networks at the
BOTANICAL GARDEN OF LEIPZIG UNIVERSITY
(18 July - 4 October 2020)
"Blüten(be)sucher - Beziehungsgeschichten aus der Natur (GERMAN only)
Restoration of degraded habitats
Photo: T. Knight
Grassland and coastal ecosystems provide valuable ecosystem services, including large contributions to global biogeochemical cycles and flood mitigation. However, many of these ecosystems have become heavily degraded by human activities. We examine the effects of habitat size, shape, exotic plant invasions, and dispersal limitation on plant community assembly. We study how to best optimize our monitoring efforts to identify at-risk species and their threats. We study the responses of rare plant species to large-scale habitat restoration.
Projects:
- Experimental restoration of grassland ecosystems
- How do we prioritize species for conservation?
- Restoration of coastal sand dunes
Climate Change
Photo: Tricklabor
Present and future climate change is a major driver of change in world´s ecosystems. How will changes in temperature and precipitation influence plant demography and population dynamics and plant biodiversity?
Projects:
- Effects of climate change on plant population dynamics and biodiversity
- Range limits and demography of Carpobrotus edulis
- Effects of climate change on plant demography in the Global Change Experimental Facility ( GCEF )
We are synthesizing the state of our knowledge on how climate change effects plant populations using
COMPADRE
, a global database of plant matrix models and in collaboration with the
sApropos
working group.
We are synthesizing the state of our knowledge on how climate change effects plant biodiversity using studies that experimentally manipulate temperature and precipitation. Further, we have initiated our own research to fill in gaps in our knowledge for certain plant species and regions of the world.
Forest community dynamics
Photo: T. Knight
Forest ecosystems have economic and cultural value, and provide vital ecosystem services. The loss of forests in developing countries is a globally recognized environmental crisis. There is an urgent need to synthesize the state of our knowledge on patterns of tree species distributions and their threats.
We contribute to global efforts to understand the macroecological patterns of tree species, and assess the threat to these species. We collaborate with the Foundation for Ecological Security (FES) in India to identify important tree species, model their species distribution and assess threats to their populations by collecting demographic data.
Projects:
- Global tree synthesis
- India tree distributions and demography

Prof. Tiffany Knight
Alexander von Humboldt Professorship Spatial Interaction Ecology
phone +49 341 9733198
fax +49 341 9739360
E-mail
tiffany.knight@idiv.de
Anne-Kathrin Thomas
Assistant
phone +49 341 9733198
fax +49 341 9739360
E-mail
anne-kathrin.thomas@idiv.de
Nina Becker
Scientific Manager (on leave)
phone +49 341 9733159
fax +49 341 9739360
E-mail
nina.becker@idiv.de
Sarah-Christine Herbst
Scientific Manager (leave replacement)
phone +49 341 9733159
fax +49 341 9739360
E-mail
sarah-christine.herbst@idiv.de
Valentin Stefan
Scientific Programmer
phone +49 341 9733112
E-mail
valentin.stefan@idiv.de
Sarah Passonneau
Research Officer for bibliometrics, bibliographic management and research in ecology
phone +49 341 9733231
E-mail
sarah.passonneau@ufz.de
Dr. Lotte Korell
Research Officer - Postdoc
phone: +49 345 5585308
E-mail
lotte.korell@ufz.de
Dr. Demetra Rakosy
Research Officer - Postdoc
phone: +49 341 9733117
E-mail
demetra.rakosy@ufz.de
Dr. Bettina Ohse
Research Officer - Postdoc
E-mail
bettina.ohse@ufz.de
Elena Motivans
Research Officer - PhD
phone: +49 341 9739144
E-mail
elena.motivans@ufz.de
Jaya Upadhyay
Research Officer - PhD
phone: +49 341 9739144
E-mail
jaya.upadhyay@ufz.de
Jared Cobain
Scientific Research Assistant
E-mail
jared.cobain@ufz.de
Simon Bitzan
Scientific Research Assistant
E-mail
simon.bitzan@ufz.de
Members of the Martin Luther University Halle-Wittenberg:
Sarah Passonneau
Research Officer - Library Scientist
phone +49 341 9733231
E-mail
sarah.passonneau@idiv.de
Dr. Aldo Compagnoni
Research Officer - Postdoc
phone +49 341 9739143
E-mail
aldo.compagnoni@idiv.de
Amibeth Thompson
Research Officer - PhD
phone +49 341 9739141
E-mail
amibeth.thompson@idiv.de
Sam Levin
Research Officer - PhD
phone +49 341 9733231
E-mail
sam.levin@idiv.de
Neeraja Venkataraman
Research Officer - PhD
phone: +49 341 9733283
E-mail
neeraja.venkataraman@idiv.de
Leana Zoller
Research Officer - PhD
phone: +49 341 9733283
E-mail
leana.zoller@idiv.de
Martin Andrzejak
Research Officer - PhD
phone: +49 341 9733188
E-mail
martin.andrzejak@idiv.de
Sanne Evers
Research Officer - PhD
phone: +49 341 9733283
E-mail
sanne.evers@idiv.de
Lara-Pauline Sittel
Technical Assistant
E-mail
lara-pauline.sittel@idiv.de
Former team members:
Michael Wohlwend
Dr. Joanne Bennett
Dr. Jeroen Everaars
Dr. Dylan Craven
Dr. Masha van der Sande
Index:
2021 (2)2020 (20)
2019 (14)
2018 (10)
2017 (5)
2016 (2)
You could use our publication index for further requests.
2021 (2)
- CaraDonna, P.J., Burkle, L.A., Schwarz, B., Resasco, J., Knight, T.M., Benadi, G., Blüthgen, N., Dormann, C.F., Fang, Q., Fründ, J., Gauzens, B., Kaiser‐Bunbury, C.N., Winfree, R., Vázquez, D.P., (2021):
Seeing through the static: the temporal dimension of plant–animal mutualistic interactions
Ecol. Lett. 24 (1), 149 - 161
full text (doi) - Dunker, S., Motivans, E., Rakosy, D., Boho, D., Mäder, P., Hornick, T., Knight, T., (2021):
Pollen analysis using multispectral imaging flow cytometry and deep learning
New Phytol. 229 (1), 593 - 606
full text (doi)
2020 (20)
- Ashman, T.-L., Arceo‐Gómez, G., Bennett, J.M., Knight, T.M., (2020):
Is heterospecific pollen receipt the missing link in understanding pollen limitation of plant reproduction?
Am. J. Bot. 107 (6), 845 - 847
full text (doi) - Barton, K.E., Jones, C., Edwards, K.F., Shiels, A.B., Knight, T., (2020):
Local adaptation constrains drought tolerance in a tropical foundation tree
J. Ecol. 108 (4), 1540 - 1552
full text (doi) - Bennett, J.M., Steets, J.A., Burns, J.H., Burkle, L.A., Vamosi, J.C., Wolowski, M., Arceo-Gómez, G., Burd, M., Durka, W., Ellis, A.G., Freitas, L., Li, J., Rodger, J.G., Ştefan, V., Xia, J., Knight, T.M., Ashman, T.-L., (2020):
Land use and pollinator dependency drives global patterns of pollen limitation in the Anthropocene
Nat. Commun. 11 , art. 3999
full text (doi) - Bernardo, H.L., Goad, R., Vitt, P., Knight, T.M., (2020):
Nonadditive effects among threats on rare plant species
Conserv. Biol. 34 (4), 1029 - 1034
full text (doi) - Blowes, S.A., Chase, J.M., Di Franco, A., Frid, O., Gotelli, N.J., Guidetti, P., Knight, T.M., May, F., McGlinn, D.J., Micheli, F., Sala, E., Belmaker, J., (2020):
Mediterranean marine protected areas have higher biodiversity via increased evenness, not abundance
J. Appl. Ecol. 57 (3), 578 - 589
full text (doi) - Chase, J.M., Blowes, S.A., Knight, T.M., Gerstner, K., May, F., (2020):
Ecosystem decay exacerbates biodiversity loss with habitat loss
Nature 584 , 238 - 243
full text (doi) - Che-Castaldo, J., Jones, O.R., Kendall, B.E., Burns, J.H., Childs, D.Z., Ezard, T.H.G., Hernandez-Yanez, H., Hodgson, D.J., Jongejans, E., Knight, T., Merow, C., Ramula, S., Stott, I., Vindenes, Y., Yokomizo, H., Salguero-Gómez, R., (2020):
Comments to “Persistent problems in the construction of matrix population models”
Ecol. Model. 416 , art. 108913
full text (doi) - Koch, V., Zoller, L., Bennett, J.M., Knight, T.M., (2020):
Pollinator dependence but no pollen limitation for eight plants occurring north of the Arctic Circle
Ecol. Evol. 10 (24), 13664 - 13672
full text (doi) - Korell, L., Auge, H., Chase, J.M., Harpole, S., Knight, T.M., (2020):
We need more realistic climate change experiments for understanding ecosystems of the future
Glob. Change Biol. 26 (2), 325 - 327
full text (doi) - Korell, L., Auge, H., Chase, J.M., Harpole, W.S., Knight, T.M., (2020):
Understanding plant communities of the future requires filling knowledge gaps
Glob. Change Biol. 26 (2), 328 - 329
full text (doi) - Levin, S.C., Crandall, R.M., Pokoski, T., Stein, C., Knight, T.M., (2020):
Phylogenetic and functional distinctiveness explain alien plant population responses to competition
Proc. R. Soc. B-Biol. Sci. 287 (1930), art. 20201070
full text (doi) - McGlinn, D.J., Engel, T., Blowes, S.A., Gotelli, N.J., Knight, T.M., McGill, B.J., Sanders, N., Chase, J.M., (2020):
A multiscale framework for disentangling the roles of evenness, density, and aggregation on diversity gradients
Ecology , e03233
full text (doi) - Sandel, B., Weigelt, P., Kreft, H., Keppel, G., van der Sande, M.T., Levin, S., Smith, S., Craven, D., Knight, T.M., (2020):
Current climate, isolation and history drive global patterns of tree phylogenetic endemism
Glob. Ecol. Biogeogr. 29 (1), 4 - 15
full text (doi) - Schmidt, R., Auge, H., Deising, H.B., Hensen, I., Mangan, S.A., Schädler, M., Stein, C., Knight, T.M., (2020):
Abundance, origin and phylogeny of plants do not predict community-level patterns of pathogen diversity and infection
Ecol. Evol. 10 (12), 5506 - 5516
full text (doi) - Schwarz, B., Vázquez, D.P., CaraDonna, P.J., Knight, T.M., Benadi, G., Dormann, C.F., Gauzens, B., Motivans, E., Resasco, J., Blüthgen, N., Burkle, L.A., Fang, Q., Kaiser–Bunbury, C.N., Alarcón, R., Bain, J.A., Chacoff, N.P., Huang, S.-Q., LeBuhn, G., MacLeod, M., Petanidou, T., Rasmussen, C., Simanonok, M.P., Thompson, A.H., Fründ, J., (2020):
Temporal scale‐dependence of plant–pollinator networks
Oikos 129 (9), 1289 - 1302
full text (doi) - Slabbert, E.L., Schweiger, O., Wubet, T., Kautzner, A., Baessler, C., Auge, H., Roscher, C., Knight, T.M., (2020):
Scale-dependent impact of land management on above- and belowground biodiversity
Ecol. Evol. 10 (18), 10139 - 10149
full text (doi) - van der Sande, M.T., Bruelheide, H., Dawson, W., Dengler, J., Essl, F., Field, R., Haider, S., van Kleunen, M., Kreft, H., Pagel, J., Pergl, J., Purschke, O., Pyšek, P., Weigelt, P., Winter, M., Attorre, F., Aubin, I., Bergmeier, E., Chytrý, M., Dainese, M., De Sanctis, M., Fagundez, J., Golub, V., Guerin, G.R., Gutiérrez, A.G., Jandt, U., Jansen, F., Jiménez‐Alfaro, B., Kattge, J., Kearsley, E., Klotz, S., Kramer, K., Moretti, M., Niinemets, Ü., Peet, R.K., Penuelas, J., Petřík, P., Reich, P.B., Sandel, B., Schmidt, M., Sibikova, M., Violle, C., Whitfeld, T.J.S., Wohlgemuth, T., Knight, T.M., (2020):
Similar factors underlie tree abundance in forests in native and alien ranges
Glob. Ecol. Biogeogr. 29 (2), 281 - 294
full text (doi) - Vitt, P., Havens, K., Jolls, C.L., Knight, T.M., (2020):
Temporal variation in the roles of exotic and native plant species in plant–pollinator networks
Ecosphere 11 (2), e02981
full text (doi) - Westerband, A.C., Knight, T.M., Barton, K.E., (2020):
Intraspecific trait variation and reversals of trait strategies across key climate gradients in native Hawaiian plants and non-native invaders
Ann. Bot. , art. mcaa050
full text (doi) - Zizka, A., Silvestro, D., Vitt, P., Knight, T.M., (2020):
Automated conservation assessment of the orchid family with deep learning
Conserv. Biol.
full text (doi)
2019 (14)
- Arceo-Gómez, G., Schroeder, A., Albor, C., Ashman, T.-L., Knight, T., (2019):
Global geographic patterns of heterospecific pollen receipt help uncover potential ecological and evolutionary impacts across plant communities worldwide
Sci. Rep. 9 , art. 8086
full text (doi) - Bennett, J.M., Steets, J.A., Burns, J.H., Durka, W., Vamosi, J.C., Arceo-Gómez, G., Burd, M., Burkle, L.A., Ellis, A.G., Freitas, L., Li, J., Rodger, J.G., Wolowski, M., Xia, J., Ashman, T.-L., Knight, T.M., (2019):
Publisher Correction: GloPL, a global data base on pollen limitation of plant reproduction
Sci. Data 6 , art. 2
full text (doi) - Bernardo, H.L., Vitt, P., Goad, R., Masi, S., Knight, T.M., (2019):
Using long-term population monitoring data to prioritize conservation action among rare plant species
Nat. Areas J. 39 (2), 169 - 181
full text (doi) - Burns, J.H., Bennett, J.M., Li, J., Xia, J., Arceo-Gómez, G., Burd, M., Burkle, L.A., Durka, W., Ellis, A.G., Freitas, L., Rodger, J.G., Vamosi, J.C., Wolowski, M., Ashman, T.-L., Knight, T., Steets, J.A., (2019):
Plant traits moderate pollen limitation of introduced and native plants: a phylogenetic meta‐analysis of global scale
New Phytol. 223 (4), 2063 - 2075
full text (doi) - Chase, J.M., Gooriah, L., May, F., Ryberg, W.A., Schuler, M.S., Craven, D., Knight, T.M., (2019):
A framework for disentangling ecological mechanisms underlying the island species–area relationship
Front. Biogeogr. 11 (1), e40844
full text (doi) - Craven, D., Knight, T.M., Barton, K.E., Bialic-Murphy, L., Chase, J.M., (2019):
Dissecting macroecological and macroevolutionary patterns of forest biodiversity across the Hawaiian archipelago
Proc. Natl. Acad. Sci. U.S.A. 116 (33), 16436 - 16441
full text (doi) - Fill, J.M., Pearson, E., Knight, T.M., Crandall, R.M., (2019):
An invasive legume increases perennial grass biomass: An indirect pathway for plant community change
PLOS One 14 (1), e0211295
full text (doi) - Havens, K., Jolls, C.L., Knight, T.M., Vitt, P., (2019):
We should know whether a tool works (and how dangerous it is) before we use it: Response to Hinz and colleagues
Bioscience 69 (11), 854 - 855
full text (doi) - Havens, K., Jolls, C.L., Knight, T.M., Vitt, P., (2019):
Risks and rewards: Assessing the effectiveness and safety of classical invasive plant biocontrol by arthropods
Bioscience 69 (4), 247 - 258
full text (doi) - Jelbert, K., Buss, D., McDonald, J., Townley, S., Franco, M., Stott, I., Jones, O., Salguero-Gómez, R., Buckley, Y., Knight, T., Silk, M., Sargent, F., Rolph, S., Wilson, P., Hodgson, D., (2019):
Demographic amplification is a predictor of invasiveness among plants
Nat. Commun. 10 , 5602
full text (doi) - Levin, S.C., Crandall, R.M., Knight, T.M., (2019):
Population projection models for 14 alien plant species in the presence and absence of above‐ground competition
Ecology 100 (6), e02681
full text (doi) - McGlinn, D.J., Xiao, X., May, F., Gotelli, N.J., Engel, T., Blowes, S.A., Knight, T.M., Purschke, O., Chase, J.M., McGill, B.J., (2019):
Measurement of Biodiversity (MoB): A method to separate the scale‐dependent effects of species abundance distribution, density, and aggregation on diversity change
Methods Ecol. Evol. 10 (2), 258 - 269
full text (doi) - Westerband, A.C., Kagawa-Viviani, A.K., Bogner, K.K., Beilman, D.W., Knight, T.M., Barton, K.E., (2019):
Seedling drought tolerance and functional traits vary in response to the timing of water availability in a keystone Hawaiian tree species
Plant Ecol. 220 (3), 321 - 344
full text (doi) - Wohlwend, M.R., Schutzenhofer, M.R., Knight, T.M., (2019):
Long-term experiment manipulating community assembly results in favorable restoration outcomes for invaded prairies
Restor. Ecol. 27 (6), 1307 - 1316
full text (doi)
2018 (10)
- Bennett, J.M., Steets, J.A., Burns, J.H., Durka, W., Vamosi, J.C., Arceo-Gómez, G., Burd, M., Burkle, L.A., Ellis, A.G., Freitas, L., Li, J., Rodger, J.G., Wolowski, M., Xia, J., Ashman, T.-L., Knight, T.M., (2018):
GloPL, a global data base on pollen limitation of plant reproduction
Sci. Data 5 , art. 180249
full text (doi) - Bennett, J.M., Thompson, A., Goia, I., Feldmann, R., Ştefan, V., Bogdan, A., Rakosy, D., Beloiu, M., Biro, I.-B., Bluemel, S., Filip, M., Madaj, A.-M., Martin, A., Passonneau, S., Kalisch, D.P., Scherer, G., Knight, T.M., (2018):
A review of European studies on pollination networks and pollen limitation, and a case study designed to fill in a gap
AoB Plants 10 (6), ply068
full text (doi) - Bernardo, H.L., Vitt, P., Goad, R., Masi, S., Knight, T.M., (2018):
Count population viability analysis finds that interacting local and regional threats affect the viability of a rare plant
Ecol. Indic. 93 , 822 - 829
full text (doi) - Bialic-Murphy, L., Gaoue, O.G., Knight, T., (2018):
Using Transfer Function Analysis to develop biologically and economically efficient restoration strategies
Sci. Rep. 8 , art. 2094
full text (doi) - Chase, J.M., McGill, B.J., McGlinn, D.J., May, F., Blowes, S.A., Xiao, X., Knight, T.M., Purschke, O., Gotelli, N.J., Adler, F., (2018):
Embracing scale‐dependence to achieve a deeper understanding of biodiversity and its change across communities
Ecol. Lett. 21 (11), 1737 - 1751
full text (doi) - Crandall, R.M., Knight, T.M., (2018):
Role of multiple invasion mechanisms and their interaction in regulating the population dynamics of an exotic tree
J. Appl. Ecol. 52 (2), 885 - 894
full text (doi) - Craven, D., Knight, T.M., Barton, K.E., Bialic-Murphy, L., Cordell, S., Giardina, C.P., Gillespie, T.W., Ostertag, R., Sack, L., Chase, J.M., (2018):
OpenNahele: the open Hawaiian forest plot database
Biodiver. Data J. 6 , art. e28406
full text (doi) - Knight, T.M., Ashman, T.-L., Bennett, J.M., Burns, J.H., Passonneau, S., Steets, J.A., (2018):
Reflections on, and visions for, the changing field of pollination ecology
Ecol. Lett. 21 (8), 1282 - 1295
full text (doi) - Pardini, E.A., Parsons, L.S., Ştefan, V., Knight, T.M., (2018):
GLMM BACI environmental impact analysis shows coastal dune restoration reduces seed predation on an endangered plant
Restor. Ecol. 26 (6), 1190 - 1194
full text (doi) - Thompson, A.H., Knight, T.M., (2018):
Exotic plant species receive adequate pollinator service despite variable integration into plant–pollinator networks
Oecologia 187 (1), 135 - 142
full text (doi)
2017 (5)
- Crawford, K.M., Knight, T.M., (2017):
Competition overwhelms the positive plant–soil feedback generated by an invasive plant
Oecologia 183 (1), 211 - 220
full text (doi) - Pardini, E.A., Patten, M.V., Knight, T.M., (2017):
Effects of seed density and proximity to refuge habitat on seed predation rates for a rare and a common Lupinus species
Am. J. Bot. 104 (3), 389 - 398
full text (doi) - Schuler, M.S., Chase, J.M., Knight, T.M., (2017):
Habitat patch size alters the importance of dispersal for species diversity in an experimental freshwater community
Ecol. Evol. 7 (15), 5774 - 5783
full text (doi) - Schuler, M.S., Chase, J.M., Knight, T.M., (2017):
Habitat size modulates the influence of heterogeneity on species richness patterns in a model zooplankton community
Ecology 98 (6), 1651 - 1659
full text (doi) - Vitt, P., Knight, T.M., Schutzenhofer, M., Kleiman, W., Havens, K., Bittner, T., (2017):
Experimental grazing and grass-specific herbicide application benefit rare forb recruitment
Nat. Areas J. 37 (2), 161 - 169
full text (doi)
2016 (2)
- Bernardo, H.L., Albrecht, M.A., Knight, T.M., (2016):
Increased drought frequency alters the optimal management strategy of an endangered plant
Biol. Conserv. 203 , 243 - 251
full text (doi) - Guthrie, S.G., Crandall, R.M., Knight, T.M., (2016):
Fire indirectly benefits fitness in two invasive species
Biol. Invasions 18 (5), 1265 - 1273
full text (doi)
2015
Crandall, R., and T.M. Knight (2015)
Positive frequency dependence undermines the success of
restoration using historical disturbance regimes. Ecology Letters 18: 883–891.
2013
Burkle, L.A., Marlin, J.C., and T.M. Knight (2013)
Plant-Pollinator Interactions over 120 Years: Loss of Species, Co-Occurrence and Function. Science 339: 1611-1615.
Powell, K.I., J.M. Chase, and T.M. Knight (2013)
Invasive plants have scale-dependent effects on biodiversity by altering the species-area relationship. Science 339: 316-318.
Burns, J.H., E.A. Pardini, M.R. Schutzenhofer, Y.A. Chung, K.J. Seidler, and T.M. Knight (2013)
Greater sexual reproduction contributes to differences in demography of invasive plants and their noninvasive relatives. Ecology 94: 995-1004.