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Genetic variation in productivity of foundation riparian species at the edge of their distribution: implications for restoration and assisted migration in a warming climate
Author(s) -
Grady Kevin C.,
Ferrier Sharon M.,
Kolb Thomas E.,
Hart Stephen C.,
Allan Gerard J.,
Whitham Thomas G.
Publication year - 2011
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1111/j.1365-2486.2011.02524.x
Subject(s) - biology , ecology , population , threatened species , genetic variation , exigua , heritability , productivity , evolutionary biology , biochemistry , demography , macroeconomics , sociology , habitat , economics , recombinant dna , spodoptera , gene
We examined the hypothesis that genotypic variation among populations of commonly co‐occurring phreatophytic trees ( P opulus fremontii , S alix gooddingii ) and the shrub ( S alix exigua ) regulates aboveground net primary productivity ( ANPP ) at a hot site at the edge of the species’ distribution. We used a provenance trial in which replicated genotypes from populations varying in mean annual temperature were transplanted to a common garden adjacent to the L ower C olorado R iver in southeastern C alifornia. The garden environment represented an extreme maximum temperature for the study species. Four major findings emerged: (1) Genotypic variation in ANPP was significant for all species with broad‐sense heritability ( H 2 ) across populations of 0.11, 0.13, and 0.10 for P . fremontii , S . gooddingii , and S . exigua , respectively, and within‐population H 2 ranging from 0.00 to 0.25, 0.00 to 0.44, and 0.02 to 0.21, respectively. (2) Population ANPP decreased linearly as mean annual maximum temperature ( MAMT ) transfer distance increased for both P . fremontii ( r 2 = 0.64) and S . gooddingii ( r 2 = 0.37), whereas it did not change for S . exigua ; (3) Populations with similar MAMT to that of the common garden were 1.5 and 1.2 times more productive than populations with 5.0 °C MAMT transfer distances for P . fremontii and S . gooddingii , respectively; and (4) Variation in regression slopes among species for the relationship between ANPP and MAMT indicate species‐specific responses to temperature. As these plant species characterize a threatened habitat type and support a diverse community that includes endangered species, ecosystem restoration programs should consider using both local genotypes and productive genotypes from warmer environments to maximize productivity of riparian ecosystems in the face of global climate change.