Department of Environmental Studies,
University of Delhi, North Campus  Delhi 110007,


Office: (91) 11-27667689


Ph.D. (Botany with specialization in Plant Ecology)                              1986 – 1992
Department of Botany, University of Delhi, Delhi 110007, India

M.Sc. Botany                                                                                                         1984 – 1986
Botany Department, Panjab University, Chandigarh 160014, India

B.Sc (Honours) Botany                                                                                      1981 – 1984
Botany Department, Hans Raj College, University of Delhi, Delhi 110007, India


  • Professor, Centre for Environmental Management of Degraded Ecosystems, University of Delhi, Delhi, India (March 2005 – Present),
  • Professor, Department of Environmental Studies (July 2010 – Present), University of Delhi, Delhi, India
  • Visiting Professor (July 2014 – November 2014), University of Alberta, Edmonton, Canada
  • Gerrit Parmile Wilder Chair Professor (August 2011 – May 2012), Botany Department, University of Hawaii at Manoa, S.A.
  • INSA-DFG Visiting Scientist (April 2007 – July 2007), Max Planck Institute for Chemical Ecology, Jena, Germany
  • Reader (equivalent to Associate Professor; June 2002 – March 2005), Department of Botany, University of Delhi, Delhi, India
  • Reader (February 2000 – June 2002), Botany Department, Panjab University, Chandigarh, India
  • Visiting Professor (June 2001 – July 2001), University of Massachusetts, USA
  • Assistant Professor (August 1998 – December 1999), The Royal University of Veterinary and Agricultural Sciences (KVL), Denmark
  • Science & Technology Agency Fellow (November 1997 – July 1998), Plant Ecochemicals Research Center, Sapporo, Japan
  • Visiting Professor (May 1997 – July 1997), Virginia Tech and State University, USA
  • Visiting Professor (May 1996 – June 1996), Second University of Napoli, Italy
  • Matsumae Fellow (July 1995 – November 1995), Hokkaido Tokai University, Sapporo, Japan
  • Post-Doctoral Fellow (December 1994 – May 1997), Lakehead University, Canada

Awards & Recognitions

  • Distinguished Visitor Award by the University of Alberta, Canada in 2016.
  • Robert H. Whittaker Distinguished Ecologist Award, Ecological Society of America, 2015
  • INSA-DFG Exchange Fellowship (2007), Max Planck Institute for Chemical Ecology, Jena.
  • Outstanding Young Weed Scientist, Weed Science Society of America, USA; 2001
  • Grodinzky Award, International Allelopathy Society, Canada; 1999
  • STA (Science & Technology Agency) Fellowship Award, Government of Japan, 1997
  • Matusmae International Fellowship Award, Matusmae Foundation, Japan; 1995
  • Associate, Indian Academy of Sciences, Banglore, India; 1995

Administrative Experience

Head, Department of Environmental Studies, University of Delhi – August 8 2012 to August 7 2015

Director, Centre for Environmental Management of Degraded Ecosystems, University of Delhi – July 2005 onwards

Past and present membership, Biodiversity Foundation, Delhi Government, National Steering Committee of GOI-UNDP-CCF-II Project on “Biodiversity Conservation through community based Natural Resource Management”; and various committees of the Department.

Secretary, International Allelopathy Society, USA; 2006 – 2011.

Editorial work – Associate/Section Editor

  • Plant and Soil, Springer (Consulting and Section Editor – 2001 to 2014)
  • Journal of Applied Ecology, Wiley (October 2016)
  • Biological Invasions, Springer ( – present)
  • AoB Plants, Oxford Press (2013 – present)
  • Scientific Reports, Nature Publishing Group (2014 – present)
  • NeoBiota, Pensoft Publishers (2014 – present)
  • Journal of Plant Ecology Oxford Publishers (served as Associate Editor for few years)
  • Guest Editor, Plant and Soil, Special issue, “Plant invasions: habitat invisibility and dominance of invasive plants” in 2005.
  • Guest Editor, Biological Invasions, Special issue, “Biological invasions” in 2008.
  • Guest Editor, AoB Plants, Special issue on, “The role of below-ground processes in mediating plant invasion” in 2015.

Research Statement, Achievements  & Current work

The primary goal of my research program is to understand ecological drivers and evolutionary processes influencing anthropogenic redistribution of biota, which has shaped my current research interests in the area of plant ecology, biodiversity and conservation.

Research achievements

  • Biological Invasions: biogeographic patterns and mechanisms: My research group has generated quantitative data to show that invasive species exert neutral to positive impacts on local biodiversity in their native ranges but exert negative impacts on native biodiversity in introduced ranges. Selected publications: Ecology (2011), PLoS ONE (2012), Global Ecology & Biogeography (2017).
  • My group has discovered some new routes of invasions or strengthens the understanding of current mechanisms. This includes: (i) evolution of increased competitive ability in an invasive species, (ii) accumulation of native soil pathogens, (iii) biogeographic variations in the production of chemicals and (iv) impact of soil nitrogen on growth of an exotic invader. Selected publications: Journal of Ecology (2008, 2011), PNAS (2009), Ecology (2011).
  • Chemical interactions among plants (Allelopathy), My lab was the first to demonstrate that allelopathy forms the basis of understanding the competitive dominance of weeds at various levels of ecological organization and showed that mediation of allelochemical activity by ecological processes, climatic and abiotic and biotic soil factors makes allelopathy conditional.
  • Selected publications: Am J Bot (1992, 1994, 1998), Can J Bot (1996, 1997, 1999, 2004), Plant & Soil (1995, 2005), Can J For Res (1998), Plant Ecol (1997), Acta Oeco (1999), Physiol Plant (1994, 2002), Planta (2009), Soil Biology & Biochemistry (2006, 2014), PLoS ONE (2009, 2010)
  • Linking plant chemicals to invasion, My research has linked interactions between allelopathy and ecosystem processes in evolutionary contexts along spatial and temporal scale. Selected publications: Trends in Ecology & Evolution (2010, 2011), Ecology Letters (2011).
  • Trends in Plant Science (2006), Plant Physiology (2012).

Current work

Chemical-driven nutrient fluctuations – My Ph.D. student is studying how Australian natives, Acacia dealbata and A. mearnsii change the nitrogen forms resulting in vegetation changes.

Genetic diversity among invasive populations – Another Ph.D. student is working on the exotic invasive species Prosopis juliflora, a native of South America. He is studying the genetic diversity among P. juliflora populations, and also quantifying invasion impacts of P. juliflora in different landscapes.

Chemical mediated plant-soil feedbacks – My lab is working to unravel plant chemicals-mediated plant-soil feedbacks. We employ comparative targeted and untargeted comparative metabolomics to study overall differences and/or similarities in the rhizosphere chemistry. My lab is collaborating to isolate pure bacterial strains from soil, which can transform/degrade carbon differentially.

Teaching Interests & Experience

I draw my teaching inspiration from my fundamental discoveries in these subjects and my strong belief in their importance. My teaching interests include courses on Community Ecology, Soil Biology or a general course on Plant Ecology. I am interested in offering courses on the Reorganization of plant communities (including Biological Invasion), Chemical Ecology or Soil Ecology. I have experience in teaching courses in Plant Ecology – Community Ecology, Soil Biology and Natural and Managed Ecosystems. I have taught courses at the Department of Botany, University of Delhi; Botany Department, Panjab University, Chandigarh, and laboratory course at the Lakehead University, Ontario; KVL University, Copenhagen, Denmark; and Botany Department, University of Hawaii, USA. I have trained several undergraduate and graduate students in Plant Ecology techniques. Currently I offer following courses at the Department of Environmental Studies.

Natural & Managed Ecosystems – I teach this course to Masters student enrolled in the Environmental Studies. Approximate strength of students generally is 25. I deal with fundamentals of plant communities with examples from natural and managed ecosystems, allelopathic interactions, plant-herbivore defense, plant competition, reorganization of plant communities, nitrogen cycle, biological invasions and weed biology.

Soil Biology – I discuss the role of soil microbial communities in shaping plant communities and nutrient cycling to highlight the role of soil, role of abiotic and biotic properties of soil in the observed variation in allelopathy and the impact of the non-native species on local species.

Keynote/Plenary/Invited Lectures/talk delivered

  • Delivered invited lecture at the Natural Resources, University of Alberta, CanadaJanuary 11 2018.
  • Delivered a plenary lecture at the 8th World Allelopathy Congress, Marseille, France, July 24-28 2017.
  • Invited by the European and Mediterranean Plant Protection Organization (EPPO) to prepare a pest risk analysis for two invasive plant species, Prosopis juliflora and Hakea sericea, May 15-19 2017, Paris, France.
  • Visited the University of Sharjah, UAE to do field work to understand the ecology of Prosopis juliflora in the UAE deserts, April 12 – 19, 2017.
  • Delivered lecture, established collaboration with the University of Kunming and Shenzen Genome Institute China, March 19 to March 24 2017, to work on the invasion and the management of Ageratina adenophora and Mikania micrantha.
  • “Impact of Ageratina adenophora on aboveground patterns and belowground processes” at the Plant Protection Institute, Chinese Academy of Sciences, Beijing, China, March 22 to March 26 2016.
  • “Ecological-evolutionary perspective of plant chemicals” at the Third Asian Allelopathy Conference, Fuzhou, China, October 30 2015 to November 2 2015.
  • “Ecological impacts of novel chemicals on aboveground patterns and belowground processes” at the University of Pittsburg, USA, June 11 2015.
  • Participated in the Discussion session at the Second HIMAP, ICIMOD workshop focused on thematic area Drivers of Change, Thimpu, Bhutan, February 4 – 6, 2015.
  • “Ecological impacts of novel chemicals on aboveground patterns and belowground processes” at the 8th International conference on Biological Invasions, Antalaya, Turkey, November 3-8 2014.
  • “Exotic plant invasion: impact of aboveground and belowground processes” at the University of Alberta, Edmonton, Canada, October 17 2014 (give a departmental seminar).
  • “Exotic plant invasion in contexts of rural development” at the Aleksandras Stulginskis University, Kauno, Lithuania, November 28-29 2013.
  • “Exotic plant invasion” at the South Agricultural University, Shenyang, China, September 13-16 2013.
  • “Exotic plant invasion: impact of aboveground and belowground processes” at the Lincoln University, Chritchurch, New Zealand, May 26-28 2013.*
  • “Novel weapons hypothesis: an ecological relevant way to study allelopathy” at the World Allelopathy Conference, Guanghzou, China, December 15 – 19 2011.
  • “Allelopathy: environmental mediation of the ecological roles of plant biochemicals” at the University of Hawaii Manoa, USA, November 4 2011.
  • “Environmental mediation of the ecological roles of allelochemicals” at the University of Toronto, Scarbrough, Canada, January 13-14 2011.*
  • “New mechanisms exotic invasive might employ for their success” at the IAP in Mediterranean Type Regions of the World, Trabzon, Turkey, Aug 2 – 6 2010.
  • “Pathways of plant invasions and factors contributing to success of invasion” at the Asia-Pacific Forest Commission meeting, Thimphu, Bhutan from June 8 – 11 2010.
  • “Allelopathy in natural ecosystems” at the First Asian Allelopathy Conference, Guanghzou, China, December 18 – 22 2009.
  • “Major and minor hypotheses for invasions” at the National Evolutionary Synthesis Center (NESCent) through the Department of Biology at Duke University, Durham, USA January 9-16 2009.
  • “Allelopathy and plant invasions” at the Netherlands Institute for Ecology (NIOO-KNAW), The Netherland, 2009 check
  • “Chemicals accumulate local microbes that inhibit native residents” at the 5th World Allelopathy Congress, Saratoga Springs, USA, September 21-25 2008.
  • University of Fribourg, Switzerland; December 18, 2007.
  • Delivered four lectures: “Allelopathy in agroecosystem”,Allelopathy history and current situation”, “Allelopathy and invasive success of nonnatives” and “Allelopathy: laboratory and field studies” at the Horticultural Central Research Institute, Yalova, Turky; 13.06.2006 – 15.06.2006
  • “Chemical ecology of weeds: allelopathy” at the Weed Science Society of America Symposium, New York, USA; 11.02.2006 – 16.02.2006
  • IV International Allelopathy Congress, Wagga Wagga, Australia; 21.08.2005 – 26.08.2005
  • “Allelopathy: challenges and achievements” at the International Botanical Congress, Vienna, Austria; 16.07.2005 – 23.07.2005.
  • “Dissociation of allelopathy from other in situ ecosystem processes” at the Max Planck Institute for Chemical Ecology, Jena, Germany; 14.07.2005 – 15.07.2005
  • Second University of Napoli, Napoli, Italy; 12.07.2005 – 13.07.2005
  • “Allelopathy: experimental problems and challenges” at the International symposium on allelopathy research and application, Guangzhou, China; 04.2004 – 29.04.2004
  • “Allelopathy: an ecological perspective” at the International Conference on theory and application of ecological agriculture, Nanchang, China; 04.2004 – 26.04.2004
  • “Implementing allelopathy for pest management problems and prospects” at the International conference on allelopathy, Lavras, Brazil,04.2004 – 16.04.2004
  • Third World Allelopathy Congress, Tsukuba, Japan; 26.08.2002 – 31.08.2002
  • Weed Science Society of America, Toronto, Canada; 02.2000 – 13.02.2000
  • First European Allelopathy Congress, Vigo, Spain; 20.06.2001 – 25.06.2001
  • XX Polyphenol Congress, Freising-Weihenstephan, Germany; 09.2000 – 18.09.2000
  • Organized a symposium and give a lecture at the Second World Allelopathy Congress, Lakehead University, Canada, 05.08.1999 – 15.08.1999
  • “Using and improving laboratory bioassays in rice allelopathy” at the Workshop on Rice Allelopathy, Manila, Philippines; 24.11.1996 – 28.11.1996
  • “Operation of allelopathy in annual and perennial cropland weeds: one example” at the First World Allelopathy Congress, Cadiz, Spain; 14.09.1996 – 23.09.1996
  • Botanical Society of America Meeting, University of Iowa, USA; 31.07.1993 – 12.08.1993

Lectures delivered at the International Conferences

  • Weed Science Society of America Meeting, Hawaii, USA; 7.2.2005 – 11.2.2005
  • Weed Science Society of America Meeting, Reno, Nevada, USA; 07.02.2002 – 17.02.2002
  • Weed Science Society of America Meeting, North Carolina, USA; 10.02.2001 – 16.02.2001
  • European Weed Research Society Meeting, Basel, Switzerland; 27.6.1999 – 2.7.1999
  • Weed Science Society of America Meeting, San Diego, California, USA; 07.02.1999 – 15.02.1999
  • Polyphenol Group Congress, Lille, France; 31.08.1998 – 06.09.1998 (Poster)
  • Weed Science Society of America Meeting, Chicago, USA; 07.02. 1998 – 14.02.1998
  • Weed Science Society of America Meeting, Colorado, USA; 07.02.1993 – 15.02.1993
  • International Society of Chemical Ecology Meeting, Kyoto, Japan; 05.07.1992 –15.07.1992
  • Weed Science Society of America, Orlando, Florida, USA; 10.02.1992 22.02.1992
  • International Society of Chemical Ecology Meeting, Laval University, Canada; 10.08.1990 – 25.08.1990.

Reviewer for peer-reviewed journals (past and present)

Trends in Ecology & Evolution, Journal of Ecology, Oikos, Ecology, Ecology Letters, Science, New Phytologist, PNAS, USA, American Journal of Botany, Plant and Soil, Trends in Plant Science, Oecologia, Tropical Agriculture, Plant Ecology, Soil Biology & Biochemistry, Journal of Environmental Quality, Journal of Chemical Ecology, Field Crops Research, Weed Technology, Weed Science, Biochemical Systematics & Ecology, Journal of Crop Science & Agronomy, Annals of Botany, Weed Research, Journal of Experimental Botany, Presilia, NeoBiota, Journal of Tropical Ecology, Journal of Crop Science & Agronomy, AoB Plants, Agronomy Journal, Scientific Reports, Environmental & Experimental Botany,