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Table 3 Country, number (NP) and area (ha) of forest patches, type of pollinators, matrix around forest patches, isolation (km), and key results of studies that have investigated the structural effects of forest patches on bees

From: Amount, distance-dependent and structural effects of forest patches on bees in agricultural landscapes

References

Country

NP

Area

Pollinator

Matrix

Isolation

Key results

[4]

Argentina

8

0.5–480

Native and honeybee

Cornfield

–

By decreasing patch size, the frequency and richness of native bees declined but the relative numbers of honeybees increased. Honeybees visiting were negatively correlated with individual trees

[120]

Brazil

2

50

Euglossine

–

–

Euglossine bees moved over cleared areas in search of fragrances

[78]

Panama

10

1–1500

Euglossine

Mixed

100–500

Euglossine bees recorded on islands were visitors from mainland sites and were equally frequent in fragments and continuous forest

[68]

Brazil

8

1–50,000

Bombus brasiliensis

Farm

4

Patches maintain greater richness and frequency of floral visitors than continuous sites

[20]

Costa Rica

22

0.25–230

Native and honeybee

Farm; pasture

500

Tree-nesting Meliponines were correlated with larger patches, smaller edge: area ratios. Honeybees showed opposite patterns

[122]

Chile

5

2–600

Native bees

Pine plantation

–

Small patches had higher species richness than continuous forests

[18]

Costa Rica

22

0.25–230

Euglossine

Pasture

0.5–19

Euglossine bees’ abundance was significantly positively correlated to forest patch size, negatively related to forest shape. Richness was negatively related to fragment area, and not related to fragment isolation

[47]

Spain

6

2–140

Native and honeybee

Farm

1–20

Large patches supported a greater flower visitor diversity, but small patches tended to have higher insect visitation rates

[79]

Brazil

9

1–354

Euglossine

Farm

> 100

Fragment size or ratio area/perimeter did not affect the abundance and richness of euglossine bees but the size of core areas positively affected them

[131]

Switzerland

–

–

Chelostoma florisomne; Hoplitis adunca

Farm

–

Forests covering a distance of up to 480 m were crossed by Chelostoma florisomne

[23]

Mexico

14

0.07–24.9

Native bees

Pasture

2

Patch size positively affected bee richness and diversity

[130]

Mexico

–

–

Euglossa dilemma

Farm

130–200

Bee populations forest remnants were neither differentiated from nor had less genetic diversity than, populations in near-continuous forest separated from 130 km of agricultural lands

[1]

Brazil

9

2–18

Euglossine

Pasture; tomato

0.05–135

The smallest forest patch had the highest abundance of bees

[61]

Brazil

4

287–94,000

Euglossine

Coffee

–

Forest shape index negatively affected euglossine abundance

[5]

Brazil

3

100–280

Euglossine

Pasture

3

The largest fragment was the main source of the observed variation in species richness and abundance

[82]

Tanzania

6

–

Megachile

Tea

–

Continuous fragments had a higher diversity of pollinators than forest patches

[48]

Australia

4

0.15–30

Honeybee

Farm

–

Honeybee abundance and pollen deposition were lower in small patches

[36]

New Zealand

15

0.01–1,000,000

Bumblebee

Grassland

–

Patch area did not affect variation in the abundance or biomass of bumblebees

[45]

Brazil

5

3–484

Native bees

Soybean

20

Patch size positively affected the abundance of Apinae and oligolectic bees and negatively affected the richness of Augochlorini bees

[114]

Canada

3

7–350

Andrena

Forest

–

Two small fragments had higher reductions in reproductive output than the continuous (350 ha) fragment

[10]

Ethiopia

–

4–100,000

Honeybee

Coffee

–

Forest fragmentation increased the relative abundance of honeybees

[98]

Brazil

–

–

Eulaema

Athletica

Oil palm; rubber tree

 

Fragment size and isolation did not affect genetic diversity

[110]

Costa Rica

12

0.9–16

Native bees

Farm

2

Fragment size did not affect bee abundance, diversity, and parasitism, and mortality rates in trap nests. Total bee abundance did not vary from edge to center. Species diversity was higher in the forest center

[13]

Ecuador

19

2.5–3500

Euglossine

Farm

0.3–17

Fragments area and isolation did not affect bee abundance, richness, or evenness

[80]

Brazil

30

15–25

Native bees

Mixed

–

Open areas had higher bee richness and diversity than forest patches

[106]

Australia

14

> 5,  < 20

Native bees

–

–

Large forest fragments had higher taxonomic diversity of bees visiting flowers of trees than small fragments. Small fragments had higher mean body sizes than those in larger fragments. The abundance of stingless bees decreased in small fragments compared to large fragments

[118]

Japan

13

1.3–10

Native bees

Farm

–

Small patches can have the same potential in maintaining as large patches. Bee richness quickly increased at the small range of the area (< 3 ha)

[65]

USA

14

5–164

Solitary bees

Mixed

0.6–19

Forest patch size did not affect bee community structure or individual family occupancy

[76]

USA

–

–

Bombus vosnesenskii; Bombus bifarius

Forest

–

Forests did not act as barriers to the fine-scale movement for either species

[44]

Norway

24

0.11–72

Bumblebee

Farm

0–428

Patch isolation negatively affected bumblebee abundance

Forest fragmentation reduced the abundance of forest specialists while increasing the abundance of open-habitat species

[66]

Norway

24

–

Native bees

Farm

–

Patch complexity negatively affected the total number of pollinators