Message-ID: <> Subject: Exported From Confluence MIME-Version: 1.0 Content-Type: multipart/related; boundary="----=_Part_8928_1281815830.1563478326934" ------=_Part_8928_1281815830.1563478326934 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Content-Location: file:///C:/exported.html Plant Species Lost in an Isolated Conservation Area in Metropoli= tan Boston from 1894 to 1993

Plant Species Lost in an Isolated Conservation Area in Metropolitan= Boston from 1894 to 1993


Brian Drayton = and Richard B. Primack



A census of the Middlesex Fells (West), a 400-ha woodland park in Metrop= olitan Boston, was undertaken in 1993 to determine how species composition = had changed since 1894 (the time of first census). This park is isolated by= an 0.5-km-wide barrier of roads and development from the eastern half of t= he Fells preserve, is at least 5 km from other protected areas, and is stro= ngly affected by human activity. Out of 422 original plant species, 155 spe= cies were no longer present in 1993, although 64 new species were recorded = on the site in 1993, the majority of them exotic. The proportion of native = species in the flora declined from 83% in 1894 to 74% in 1993. Overall, the= number of native species is declining at a rate of 0.36% per year, whereas= the exotic species are increasing at a rate of 0.18% per year. Many of the= native species lost were attractive and well-known components of the nativ= e flora, such as orchids and lobeliads. Many remaining native plant species= have been reduced to one or a few small populations. Species of moist wood= s were disproportionately lost from the Fells. The loss of species has coin= cided with an increase in human activity, including ground fires, a greater= number of trails and roads, thinning of the forest, and trampling of the v= egetation. Methods are suggested for stopping and reversing this progressiv= e loss of species.

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