Floristic Changes in the Understory Vegetation of Mixed Temperate New England Freshwater Island Forests over a Period of 33 Years.

Marjorie M Holland,Mark Winkler

doi:10.3390/plants9111600

Abstract

During a 33-year sampling period, we observed species richness and calculated species evenness and Shannon Diversity for understory woody seedlings and herbaceous species on three small islands in Lake Winnipesaukee, New Hampshire, and noted consistency of dominant plant species over time. Seedlings and herbaceous species were recorded and measured in 25 permanent plots that were created on the three islands in 1978. The understory species data were compiled by frequency and dominance of woody seedlings and herbaceous species. Data from 250 individual quadrats show that species richness more than doubled from 41 in 1978 to 83 species on all three islands in 2011. Species evenness on all the islands remained relatively constant in each of the four samplings. The combined Shannon’s Diversity for the three islands rose from 2.76 in 1978 to 3.37 in 2011. Dominant species in the study were Aralia nudicaulis, Gaultheria procumbens, Gaylussacia baccata, Maianthemum canadense, and Tsuga canadensis seedlings.

Highlights

Many of the environmental problems that challenge human society are fundamentally ecological in nature, and are threatening the sustainability of Earth0 s life support systems
Was published, members of the international ecological community met in Mexico to recommend the International Sustainable Biosphere Initiative, noting the concept of sustainability implies the use of ecological systems in a manner that satisfies current needs without compromising the needs or options of future generations [2]
Based on our observations and knowledge of the islands in the 1970s [8,19], we predicted total species richness would be highest on the largest island which supports seven habitats (Three Mile), lowest on the smallest island with only three habitats (Blueberry), and that species richness would increase over time as parts of each island gained increased protection [20]

Summary

Introduction

Many of the environmental problems that challenge human society are fundamentally ecological in nature, and are threatening the sustainability of Earth0 s life support systems. Our island studies began in the late 1970s, and our second detailed assessment was conducted shortly after the release of the SBI report, reinforcing the need for long-term ecological assessment of biological diversity and habitat change. In this manuscript, we assess the influence of environmental variation and land-use history on forest floor plant composition and distribution on islands in central. We focus on the vegetation of three of the 253 islands in Lake

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