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Effects of agricultural intensification on ability of natural enemies to control aphids.

Zhao ZH, Hui C, He DH, Li BL - Sci Rep (2015)

Bottom Line: It is however extremely difficult to disentangle the effects of agricultural intensification on arthropod communities at multiple spatial scales.Both the input of nitrogen fertilizer and cropland expansion benefited cereal aphids more than primary parasitoids and leaf-dwelling predators, while suppressing ground-dwelling predators, leading to an disturbance of the interspecific relationship.As such, agricultural intensification (increasing nitrogen fertilizer and cropland expansion) can destabilize the interspecific relationship and lead to biodiversity loss.

View Article: PubMed Central - PubMed

Affiliation: Department of Entomology, College of Agriculture and Biotechnology, China Agricultural University. Beijing 100193, P. R. China.

ABSTRACT
Agricultural intensification through increasing fertilization input and cropland expansion has caused rapid loss of semi-natural habitats and the subsequent loss of natural enemies of agricultural pests. It is however extremely difficult to disentangle the effects of agricultural intensification on arthropod communities at multiple spatial scales. Based on a two-year study of seventeen 1500 m-radius sites, we analyzed the relative importance of nitrogen input and cropland expansion on cereal aphids and their natural enemies. Both the input of nitrogen fertilizer and cropland expansion benefited cereal aphids more than primary parasitoids and leaf-dwelling predators, while suppressing ground-dwelling predators, leading to an disturbance of the interspecific relationship. The responses of natural enemies to cropland expansion were asymmetric and species-specific, with an increase of primary parasitism but a decline of predator/pest ratio with the increasing nitrogen input. As such, agricultural intensification (increasing nitrogen fertilizer and cropland expansion) can destabilize the interspecific relationship and lead to biodiversity loss. To this end, sustainable pest management needs to balance the benefit and cost of agricultural intensification and restore biocontrol service through proliferating the role of natural enemies at multiple scales.

No MeSH data available.


Related in: MedlinePlus

The effects of the proportion of cropland at the 500 m scale on parasitism, predator/pest ratio, and species diversity in wheat fields ((A) primary parasitism; (B) predator/pest ratio for leaf-ground predators; (C) predator/pest ratio for ground-dwelling predators; (D) species diversity).
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f4: The effects of the proportion of cropland at the 500 m scale on parasitism, predator/pest ratio, and species diversity in wheat fields ((A) primary parasitism; (B) predator/pest ratio for leaf-ground predators; (C) predator/pest ratio for ground-dwelling predators; (D) species diversity).

Mentions: Moreover, we selected the scale of 500 m to examine the effects of the proportion of cropland on predation and parasitism, showing an insignificant effect on primary parasitism (F1,101 = 2.36, P = 0.127, Figure 4A) but a negative effect on the predator/pest ratio (Leaf-dwelling predators: F1,101 = 5.58, P = 0.020; Ground-dwelling predators: F1,101 = 6.97, P = 0.010, Figure 4B, C) and a negative effect on the species diversity of natural enemies (F1,101 = 6.61, P = 0.012, Figure 4D).


Effects of agricultural intensification on ability of natural enemies to control aphids.

Zhao ZH, Hui C, He DH, Li BL - Sci Rep (2015)

The effects of the proportion of cropland at the 500 m scale on parasitism, predator/pest ratio, and species diversity in wheat fields ((A) primary parasitism; (B) predator/pest ratio for leaf-ground predators; (C) predator/pest ratio for ground-dwelling predators; (D) species diversity).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4306106&req=5

f4: The effects of the proportion of cropland at the 500 m scale on parasitism, predator/pest ratio, and species diversity in wheat fields ((A) primary parasitism; (B) predator/pest ratio for leaf-ground predators; (C) predator/pest ratio for ground-dwelling predators; (D) species diversity).
Mentions: Moreover, we selected the scale of 500 m to examine the effects of the proportion of cropland on predation and parasitism, showing an insignificant effect on primary parasitism (F1,101 = 2.36, P = 0.127, Figure 4A) but a negative effect on the predator/pest ratio (Leaf-dwelling predators: F1,101 = 5.58, P = 0.020; Ground-dwelling predators: F1,101 = 6.97, P = 0.010, Figure 4B, C) and a negative effect on the species diversity of natural enemies (F1,101 = 6.61, P = 0.012, Figure 4D).

Bottom Line: It is however extremely difficult to disentangle the effects of agricultural intensification on arthropod communities at multiple spatial scales.Both the input of nitrogen fertilizer and cropland expansion benefited cereal aphids more than primary parasitoids and leaf-dwelling predators, while suppressing ground-dwelling predators, leading to an disturbance of the interspecific relationship.As such, agricultural intensification (increasing nitrogen fertilizer and cropland expansion) can destabilize the interspecific relationship and lead to biodiversity loss.

View Article: PubMed Central - PubMed

Affiliation: Department of Entomology, College of Agriculture and Biotechnology, China Agricultural University. Beijing 100193, P. R. China.

ABSTRACT
Agricultural intensification through increasing fertilization input and cropland expansion has caused rapid loss of semi-natural habitats and the subsequent loss of natural enemies of agricultural pests. It is however extremely difficult to disentangle the effects of agricultural intensification on arthropod communities at multiple spatial scales. Based on a two-year study of seventeen 1500 m-radius sites, we analyzed the relative importance of nitrogen input and cropland expansion on cereal aphids and their natural enemies. Both the input of nitrogen fertilizer and cropland expansion benefited cereal aphids more than primary parasitoids and leaf-dwelling predators, while suppressing ground-dwelling predators, leading to an disturbance of the interspecific relationship. The responses of natural enemies to cropland expansion were asymmetric and species-specific, with an increase of primary parasitism but a decline of predator/pest ratio with the increasing nitrogen input. As such, agricultural intensification (increasing nitrogen fertilizer and cropland expansion) can destabilize the interspecific relationship and lead to biodiversity loss. To this end, sustainable pest management needs to balance the benefit and cost of agricultural intensification and restore biocontrol service through proliferating the role of natural enemies at multiple scales.

No MeSH data available.


Related in: MedlinePlus