Open AccessMortality rate estimation for eelgrass Zostera marina (Potamogetonaceae) using projections from Leslie matrices
Author(s) -
Olga Flores Uzeta,
Elena Solana Arellano,
Héctor Echavarría Heras
Publication year - 2006
Publication title -
revista de biología tropical
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.305
H-Index - 38
eISSN - 2215-2075
pISSN - 0034-7744
DOI - 10.15517/rbt.v56i3.5689
Subject(s) - zostera marina , seagrass , statistics , potamogetonaceae , demography , zostera , ecology , sampling (signal processing) , biology , growing season , mathematics , zoology , ecosystem , filter (signal processing) , sociology , computer science , computer vision
The main goal of this study is to provide estimations of mean mortality rate of vegetative shoots of the seagrass Zostera marina in a meadow near Ensenada Baja California, using a technique that minimizes destructive sampling. Using cohorts and Leslie matrices, three life tables were constructed, each representing a season within the period of monthly sampling (April 1999 to April 2000). Ages for the cohorts were established in terms of Plastochrone Interval (PI). The matrices were projected through time to estimate the mean total number of individuals at time t, n(t) as well as mortality. We found no statistical differences between observed and predicted mean values for these variables (t = -0.11, p = 0.92 for n(t) and t = 0.69, p = 0.5 for mean rate of mortality). We found high correlation coefficient values between observed and projected values for monthly number of individuals (r = 0.70, p = 0.007) and monthly mortality rates (r = 0.81, p = 0.001). If at a certain time t a sudden environmental change occurs, and as long as the perturbation does not provoke the killing of all the individuals of a given age i for 0 < or = i < or = x - 1, there will be a prevailing number of individuals of age or stage x at a time t+1. This nondestructive technique reduces the number of field visits and samples needed for the demographic analysis of Z. marina, and therefore decreases the disturbance caused by researches to the ecosystem.