Plant diversity in highly fragmented forest landscapes in Mexico and Chile: implications for conservation.

Abstract:Several studies have evaluated the short-term effects of tropical forest fragmentation on plant taxonomic diversity, while only a few have evaluated its effects on functional or phylogenetic diversity. To our knowledge no study has looked at the long-term consequences of tropical forest fragmentation on the three main components of plant diversity simultaneously: taxonomic, functional and phylogenetic diversity. We sampled the vascular flora using belt transects (50 × 4 m) in a continuous tropical semi-evergreen forest (16 transects) and in an adjacent naturally fragmented forest (fragments of 1.7-My-old semi-evergreen forest immersed in a mangrove/sedge matrix) (18 transects), and compared their taxonomic, functional and phylogenetic plant diversity. There were 36 species in the continuous forest and 28 in the fragmented forest. Continuous forest was taxonomically more diverse (25%) than the fragmented forest. All functional diversity metrics were greater (6–33%) in the continuous than in the fragmented forest. Phylogenetic diversity was 19% greater and phylogenetically more overdispersed in the continuous forest than in the fragmented forest. The results suggest that in the fragmented forest not only is taxonomic plant diversity lower, but functional and phylogenetic diversity are as well. The negative effects of forest fragmentation on plant diversity seem to be chronic.

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Effects of habitat fragmentation: increased isolation and reduced habitat size reduces the incidence of dead wood fungi beetles in a fragmented forest landscape

Ecography ◽

10.1034/j.1600-0587.2000.230411.x ◽

2000 ◽

Vol 23 (4) ◽

pp. 492-502 ◽

Cited By ~ 9

Author(s):

Bjorn Arne Rukke

Keyword(s):

Habitat Fragmentation ◽

Dead Wood ◽

Forest Landscape ◽

Habitat Size ◽

Fragmented Forest

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Plant diversity and species richness of Ljubljana marsh grasslands under the influence of different cutting and fertilizing regimes

Acta Agronomica Hungarica ◽

10.1556/aagr.57.2009.2.11 ◽

2009 ◽

Vol 57 (2) ◽

pp. 197-203 ◽

Cited By ~ 2

Author(s):

T. Sinkovč

Keyword(s):

Species Richness ◽

Plant Diversity ◽

Grassland Management ◽

Botanical Composition ◽

Significant Negative Effect ◽

Negative Effect ◽

Cutting Regimes ◽

N Rates ◽

Exploitation Intensity ◽

Plot Design

The botanical composition of grasslands determines the agronomic and natural values of swards. Good grassland management usually improves herbage value, but on the other hand it frequently decreases the plant diversity and species richness in the swards. In 1999 a field trial in a split-plot design with four replicates was therefore established on the Arrhenatherion type of vegetation in Ljubljana marsh meadows in order to investigate this relationship. Cutting regimes (2 cuts — with normal and delayed first cut, 3 cuts and 4 cuts per year) were allocated to the main plots and fertiliser treatments (zero fertiliser — control, PK and NPK with 2 or 3 N rates) were allocated to the sub-plots. The results at the 1 st cutting in the 5 th trial year were as follows: Fertilising either with PK or NPK had no significant negative effect on plant diversity in any of the cutting regimes. In most treatments the plant number even increased slightly compared to the control. On average, 20 species were listed on both unfertilised and fertilised swards. At this low to moderate level of exploitation intensity, the increased number of cuts had no significant negative effect on plant diversity either (19 species at 2 cuts vs. 20 species at 3 or 4 cuts). PK fertilisation increased the proportion of legumes in the herbage in the case of 2 or 3 cuts. The proportion of grasses in the herbage increased in all the fertilisation treatments with an increased numbers of cuts. Fertiliser treatment considerably reduced the proportion of marsh horsetail ( Equisetum palustre ) in the herbage of the meadows. This effect was even more pronounced at higher cut numbers. The proportion of Equisetum palustre in the herbage was the highest in the unfertilised sward with 2 cuts (26.4 %) and the lowest in the NPK-fertilised sward with 4 cuts (1.4%).

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