Interactions of nutrients, plant growth and herbivory in a Parangipettai mangrove ecosystem of the Vellar estuary, Southeast coast of India

• Relationship among nutrients, plant growth and herbivory in mangrove ecosystem has been studied.
• Total amino acids, nitrogen, phosphorus and potassium were highest in Rhizophora mucronata.
• Tannin and total sugars were maximum in Avicennia officinalis.
• Young leaves suffered higher losses to herbivory than mature leaves due to leaf chemistry.
• This study revealed influence of nutrients and leaf chemistry in mangroves on herbivory intensity.

The objective of this present attempt was to investigate the relationship between leaf quality and level of herbivory at study site during August 2010–July 2011. Total amino acids with a maximum of 9.47 mg g−1 during February 2011 in Rhizophora mucronata and a minimum of 4.671 mg g−1 in May 2011 in Avicennia officinalis were noticed. Tannin was maximum (6.844 mg g−1) during April 2011 and minimum (0.667 mg g−1) in July 2011 in  A. officinalis. Total nitrogen showed a maximum of 9.851 mg g−1 during February 2011 in R. mucronata and a minimum of 2.158 mg g−1 in February 2011 in A. officinalis. Total sugars registered a maximum of 4.075 mg g−1 during March 2011 in A. officinalis and a minimum of 0.063 mg g−1 in March 2011 in R. mucronata. Total phosphorus recorded the maximum (4.321 mg g−1) during November 2010 in R. mucronata and minimum (0.258 mg g−1) during May 2011 in A. officinalis. Potassium content was maximum (3.710 mg g−1) during October 2010 in R. mucronata and minimum (0.039 mg g−1) in July 2011 in A. officinalis. These data suggest that artificially developed mangrove ecosystems may be an adaptive mechanism related to nutrient conservation, and that it is associated with mangrove survival in phosphorus-deficient soil rather than an adaptation to herbivory.