Although landscape fragmentation and simplification due to agriculture is extensive, wildlife corridors can help to promote a healthy ecosystem. Corridors which allow wildlife and plant populations to move between one patch and another enhance the chance for survivorship and genetic health. These corridors can come in many forms, including riparian zones and vegetation strips known as hedgerows and many vineyards are beginning to focus attention on their creation.
Expansion of monocultures has decreased abundance and activity of natural enemies. Scientists are concerned that accelerated rates of habitat removal will noticeably affect pest control by biocontrol agents.
In order to combat this problem, many farmers and researchers have proposed increasing the vegetational diversity of agricultural landscapes through methods such as planting vegetation adjacent to a crop field or including hedgerows within a field.
A hedgerow is a line or grouping of trees, shrubs, perennials, herbs, annuals, grasses and vines planted along fence lines, property lines, agricultural borders, water areas etc. Using a diversity of plant materials lures insects, which in turn bring beneficial predators such as other insects, birds, toads, frogs and lizards.
Lately, many farmers have been using hedgerows with a diversity of plants and flowering periods in order to provide habitat for failing bee populations.
For a comprehensive guide on hedgerows, including considerations when planting a hedgerow, cost estimates, maintenance suggestions as well as plant lists, you can download the 70-page (3-megabyte pdf) Hedgerows for California Agriculture by Sam Earnshaw.