 variability</strong></p>
<p>In the above example for fitting multiple species at once, we have already offered a glimpse on how to include the effect of environmental covariates over lambda and alpha values. The relevant arguments in <code>cxr_pm_fit</code> and <code>cxr_pm_multifit</code> are ‘lambda_cov_form’ and ‘alpha_cov_form’. If these are set to ‘none’, no effect of covariates is considered. Otherwise, there are a couple options to model this effect (all the options consider linear effec