TN_190_RP_2 - TN 190-RP-2 - Developing Temporal Biomass Production Curves (Growth Curves) for Annual and Perennial Grass Species for Ecological Site Descriptions
TN 190-RP-2 - Developing Temporal Biomass Production Curves (Growth Curves) for Annual and Perennial Grass Species for Ecological Site Descriptions
Technical Notes: 190-RP-2 Date: December 18, 2018
Subject: ECS – Developing Temporal Biomass Production Curves (Growth Curves) for Annual and Perennial Grass Species for Ecological Site Descriptions


 
Purpose.  To provide guidance on how to develop temporal biomass production curves (growth curves) for annual and perennial grass species for ecological site descriptions.
 
Expiration Date.  Effective upon receipt.
 
Explanation.  The technical note provides guidance on how to determine growth curves from both established grasses and newly established grasses. Growth curve data and graphical representations are important in showing growth of plants over time. Growth curve data used in ecological site descriptions represent average values; however, rates of growth of a plant will vary with climatic factors (available water and temperature). Typically, a growth curve is sigmoid in shape and shows a dormant phase, a lag phase representing initial startup growth, the log or exponential phase where maximum growth occurs, and a diminishing phase where growth slows and eventually stops. Some plant species exhibit a bimodal growth curve with two or more growth periods.
 
Distribution.  This directive is available on the NRCS Electronic Directives System website at https://directives.sc.egov.usda.gov/.
 
Contact.  Questions regarding this technical note should be directed to Johanna Pate, rangeland management specialist, at (817) 509-3227 or Johanna.Pate@ftw.usda.gov.
 
 

 /s/

DIANE GELBURD
Acting Deputy Chief for Science and Technology

 
 

Attachment A - TN 190-RP-2 

Attachment B - Spreadsheet

[TN_190_RP_2 - December 2018]