Reinvasion of restored California vernal pools reveals the importance of long‐term restoration planning

Ecological restoration often focuses on short‐term intervention efforts with the goal of creating restored ecosystems that do not require continuous human maintenance. Here, we ask: Do short‐term restoration efforts result in self‐sustaining native assemblages, or do these restored ecosystems require long‐term management to prevent reinvasion of exotic species? We address this question using restored vernal pool wetlands in coastal California. Restoration efforts in vernal pool ecosystems are often hindered because many restored vernal pools exist within a grassland matrix that is highly invaded by exotic annual grasses and forbs. To test whether restored pools experienced reinvasion, we assessed plant species abundance and diversity at varying times after intensive weeding had ceased. The central bottom of pools, where inundation duration is the longest, showed stable or even increasing native cover and no trends in exotic abundance over time. However, exotic cover and richness increas..., Approach 1: Multi-Year Monitoring Study (\"np_percent_cover.csv\")
From 2016 to 2019, we monitored seven restored vernal pools within UCSB’s North Parcel, which consists of vernal pools built amidst university faculty housing.  Within each restored vernal pool, we established a series of permanent monitoring quadrats.  We delineated each pool into central (experiencing longest inundation period), transition (inundated or hydric soil during longest inundation period), and upland (inundated during extreme storms but otherwise non-hydric soils) zones (Figure 2A).  Within each of these zones, we haphazardly placed three 1m2 quadrats, for a total of nine quadrats per pool.  We monitored the vernal pools monthly from November 2016 to December 2019.  Because the pools were different ages at the start of the experiment, sampling over three years allowed us to evaluate the vegetation community in pools ages two to nine years old.  Within each quadrat, we determined th..., , # Reinvasion of restored California vernal pools reveals the importance of long‐term restoration planning

[https://doi.org/10.25349/D97P6W](https://doi.org/10.25349/D97P6W)

\# Approach 1: Multi\-Year Monitoring Study \(\"np\_percent\_cover\.csv\"\)
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From 2016 to 2019, we monitored seven restored vernal pools within UCSB’s North Parcel, which consists of vernal pools built amidst university faculty housing.  Within each restored vernal pool, we established a series of permanent monitoring quadrats.  We delineated each pool into central (experiencing longest inundation period), transition (inundated or hydric soil during longest inundation period), and upland (inundated during extreme storms but otherwise non-hydric soils) zones (Figure 2A).  Within each of these zones, we haphazardly placed three 1m² quadrats, for a total of nine quadrats per pool.  We monitored the vernal pools monthly from November 2016 to December 2019.  Because the pools were different ages at the start o...,