Effects of vineyard coverage and extent on benthic macroinvertebrates in streams of Northern California

Abstract

-Vineyards are a dominant feature of many landscapes in Mediterranean-climate regions. We examined the effects of streamflow declines, associated with vineyard water-withdrawals for frost protection, on benthic-macroinvertebrate communities at three sites along three small streams in the Mediterraneanclimate region of Northern California. One site was heavily affected by water withdrawals for frost protection, the other two were not. In addition, we examined relationships between vineyard coverage and benthicmacroinvertebrate community response using data from 59 sampling events at 39 sites along 35 small streams in Napa County, California. We tested three a priori hypotheses in terms of the response of biological traits of benthic macroinvertebrates to high vineyard coverage: (1) proportion of individuals with semi-voltine (i.e., one generation every 2 years) life cycles would be lower compared to those with uni-and multi-voltine cycles, (2) proportion of individuals able to undergo diapause would be higher, and (3) proportion of individuals with the ability to burrow into the substrate would be higher. In the three-site study, we found that vineyard water-withdrawals for frost protection coincided with consistently lower values in both the benthic-macroinvertebrate index of biotic integrity (B-IBI) developed for Northern California streams and the ratio of Ephemeroptera-Plecoptera-Trichoptera to Odonata-Coleoptera-Hemiptera individuals (EPT/OCH), a metric developed for European Mediterranean streams. In the broader-scale study, we observed that vineyard-coverage levels above about 20% coincided with lower values of the B-IBI. The semi-voltine life-cycle trait was lower above this level, whereas the diapause and burrowing traits were not affected.

Vulnerability of stream biota to climate change in mediterranean climate regions: a synthesis of ecological responses and conservation challenges

“…As climate change might favour species that are more tolerant to higher water temperatures and pollution, or to water withdrawals (Gasith, 1991;Davies et al, 1993;Sabater et al, 1995;Gasith & Resh, 1999;Lawrence et al, 2011), biological invasions of non-native species are expected to occur more frequently, and biotic communities will tend to be more homogenised and with fewer endemic species (Clavero & García-Berthou, 2006). Such alterations in communities will lead to poorer stream 'ecological status', as defined in current management programs worldwide, such as the Water Framework Directive or the Clean Water Act (Moyle, 1995;Munné & Prat, 2010;see Table 2 for details).…”

Climate change, wine, and conservation

“…Water use by vineyards creates conservation concern for freshwater habitats (22,23). Vineyard water use for frost damage prevention has resulted in significant flow reduction in California streams (23).…”

Shifts in aquatic macroinvertebrate community structure in response to perenniality, southern Cape, South Africa

“…Bêche and Statzner (2009) suggest that as there is 'no systematic difference among the factors influencing stream ecological processes across different climatic and biogeographic regions' citing Boulton et al (2008), 'then stream communities from disparate regions should be functionally similar'. However, there has been much research conducted on Mediterranean-climate regions (MCRs) in North America (Lawrence et al 2010(Lawrence et al , 2011, Australia (Paltridge et al 1997), Europe, (Bonada, Dol edec, & Statzner 2007;S anchez-Montoya et al 2007) and South Africa (de Moor & Day 2013) as these streams display highly seasonal discharge patterns. Conceptual models, such as the Habitat Templet Theory (Southwood 1988;Bogan & Lytle 2011), schematically represent the successional pathways communities may take in response to disturbance.…”