Comparing conventional and organic olive groves in central Greece: plant and bird diversity and abundance

2011 ◽  
Vol 26 (4) ◽  
pp. 297-316 ◽  
Author(s):  
Alexandra Solomou ◽  
Athanassios Sfougaris

AbstractThe present study was conducted in Magnesia Prefecture, central Greece, during the period May–June 2007. It aimed at the comparison between conventional and certified organic olive groves with regard to olive and olive oil production, diversity of plants (herbaceous and woody) and diversity and abundance of avifauna. Correlations between variables within herbaceous plants (linear regression) and woody plants (Principal Component Analysis), and the role of integration time of olive groves to the organic system were investigated. Also, finding easily measurable parameters indicating high bird diversity levels within organic and conventional management systems was a main target of the study. According to our findings, neither edible olive yield nor olive oil yield showed significant differences between conventional and certified organic olive groves. There is an increasing trend for alpha and beta diversity of herbaceous plant species, woody plant beta diversity, density and cover of woody plants, and density of breeding birds in certified organic olive groves (10 years) in comparison with conventional ones. The effect of time since the adoption of organic procedures is very important and produces benefits for the biodiversity. In the total olive groves 15 insectivorous, six granivorous and three insectivorous/granivorous birds species were recorded. Nine bird species distinguished by Ward's hierarchical clustering were identified as typical (indicator value, IndVal>50%) of specific farming systems. Among them, the Eurasian jay, associated with the 10-year certified organic olive groves, and the common cuckoo, Orphean warbler and Red-backed shrike, associated with the 6-year certified organic olive groves, should be regarded as characteristic species (IndVal>70%). Conclusively, organic farming favors some aspects of diversity of herbaceous and woody plants of olive grove ecosystems. On the contrary, similar effects on breeding bird diversity and density were not clearly recorded. However, breeding bird density proved a good indicator of their richness.

2020 ◽  
Vol 12 (7) ◽  
pp. 3059
Author(s):  
Luis Gomes ◽  
Tânia Nobre ◽  
Adélia Sousa ◽  
Fernando Rei ◽  
Nuno Guiomar

Worldwide sustainable development is threatened by current agricultural land change trends, particularly by the increasing rural farmland abandonment and agricultural intensification phenomena. In Mediterranean countries, these processes are affecting especially traditional olive groves with enormous socio-economic costs to rural areas, endangering environmental sustainability and biodiversity. Traditional olive groves abandonment and intensification are clearly related to the reduction of olive oil production income, leading to reduced economic viability. Most promising strategies to boost traditional groves competitiveness—such as olive oil differentiation through adoption of protected denomination of origin labels and development of value-added olive products—rely on knowledge of the olive varieties and its specific properties that confer their uniqueness and authenticity. Given the lack of information about olive varieties on traditional groves, a feasible and inexpensive method of variety identification is required. We analyzed leaf spectral information of ten Portuguese olive varieties with a powerful data-mining approach in order to verify the ability of satellite’s hyperspectral sensors to provide an accurate olive variety identification. Our results show that these olive varieties are distinguishable by leaf reflectance information and suggest that even satellite open-source data could be used to map them. Additional advantages of olive varieties mapping were further discussed.


2011 ◽  
Vol 278 (1721) ◽  
pp. 3081-3088 ◽  
Author(s):  
Rachel D. Field ◽  
John D. Reynolds

Pacific salmon ( Oncorhynchus spp.) returning to streams around the North Pacific Rim provide a nutrient subsidy to these ecosystems. While many species of animals feed directly on salmon carcasses each autumn, salmon-derived nutrients can also be stored in coastal habitats throughout the year. The effects of this storage legacy on vertebrates in other seasons are not well understood, especially in estuaries, which can receive a large portion of post-spawning salmon nutrients. We examine the effects of residual salmon-derived nutrients, forest habitats and landscape features on summer breeding birds in estuary forests. We compared models containing environmental variables and combined chum ( Oncorhynchus keta ) and pink ( Oncorhynchus gorbuscha ) salmon biomass to test predictions concerning bird density and diversity. We discovered that total bird, insectivore, golden-crowned kinglet and Pacific wren densities and Shannon's diversity in the summer were strongly predicted by salmon biomass in the autumn. For most metrics, this relationship approaches an asymptote beyond 40 000 kg of salmon biomass. Foliage height diversity, watershed catchment area and estuary area were also important predictors of avian communities. Our study suggests that the legacy of salmon nutrients influences breeding bird density and diversity in estuaries that vary across a wide gradient of spawning salmon biomass.


2018 ◽  
Author(s):  
Jin-Yong Kim ◽  
Sanghun Lee ◽  
Man-Seok Shin ◽  
Chang-Hoon Lee ◽  
Changwan Seo ◽  
...  

Altitudinal patterns in the population ecology of mountain bird species are useful for predicting species occurrence and behavior. Numerous hypotheses about the complex interactions among environmental factors have been proposed; however, these remain controversial. This study investigated the causes of altitudinal patterns in breeding bird species richness and density in relation to climate, habitat heterogeneity, and migration influence in Jirisan National Park, South Korea. We conducted a field survey of 142 plots at altitudes between 200 and 1400 m above mean sea level in the breeding season. A total of 2771 individuals from 53 breeding bird species were recorded. Altitudinal patterns of species richness and density showed a hump-shaped pattern, indicating that the highest richness and density could be observed at moderate altitudes. Models constructed with 16 combinations of six variables demonstrated that species richness was positively correlated with vertical and horizontal habitat heterogeneity, and that density was positively correlated with vertical, but not horizontal, habitat heterogeneity, and negatively correlated with migrant rate. No significant relationships were found between spring temperature and species richness or density. Therefore, the observed patterns in species richness support the hypothesis that habitat heterogeneity, rather than climate, is the main driver of species richness. And neither habitat heterogeneity nor climate hypotheses fully explains the observed patterns in density. However, vertical habitat heterogeneity does likely help explain observed patterns in density. The heterospecific attraction hypothesis did not apply to the distribution of birds along the altitudinal gradient. Appropriate management of vertical habitat heterogeneity, such as vegetation cover, should be maintained for the conservation of bird diversity in this area.


Plant Disease ◽  
2021 ◽  
Author(s):  
Emmanouil Alexandros Markakis ◽  
Emmanouil N. Roditakis ◽  
Georgios S. Kalantzakis ◽  
Anastasia Chatzaki ◽  
Stefanos K. Soultatos ◽  
...  

In November 2019, a severe outbreak of fruit rot was observed in olive orchards in Crete, southern Greece. Symptoms appeared primarily on fruits and stalks, resembling those caused by anthracnose. Typical symptoms were fruit rot, shrinkage and mummification, associated commonly with stalk discoloration and fruit drop. Disease incidence was estimated up to 100% in some cases and an unprecedented increase in olive oil acidity reaching up to 8% (percentage of oleic acid) in severely affected olive groves was recorded. Thirty-two olive groves were then surveyed, and samples of fruit, stalk, leaf and shoot were collected. Visual, stereoscopic and microscopic observations revealed several fungi belonging to the genera Alternaria, Botryosphaeria, Capnodium, Colletotrichum, Fusarium and Pseudocercospora. Fungal infection in fruits was commonly associated with concomitant infestation by the olive fruit fly Bactrocera oleae along with increased air temperature and relative humidity conditions that prevailed in October-November 2019. Twenty representative fungal strains isolated from symptomatic fruits and stalks were characterized by morphological, physiological and molecular analyses. By rDNA-ITS region and EF1-α gene sequencing analysis, these isolates were identified as Alternaria spp., A. infectoria, Botryosphaeria dothidea, Colletotrichum boninense sensu lato, Fusarium lateritium, F. solani species complex and Stemphylium amaranthi. Pathogenicity tests on punctured fruits revealed that all isolates were pathogenic; however F. solani isolates along with B. dothidea were the most virulent and wounds were necessary for efficient fungal infection. Moreover, as little as 10 spores of F. solani were sufficient of causing significant infection in punctured fruits. Fusarium solani was also capable of infecting olive fruits in the presence of B. oleae, with no additional wounding, in artificial inoculation experiments. Moreover, it was capable of colonizing and affecting olive blossoms. Further analyses in olive oil extracted from fruits artificially inoculated with F. solani indicated a significant increase in oil acidity, K232, K270 and peroxide value, whereas total phenols content was significantly decreased. To the best of our knowledge, this is the first report of Fusarium solani associated with olive fruit rot and olive oil degradation worldwide.


2016 ◽  
Vol 25 (4) ◽  
pp. 653-671 ◽  
Author(s):  
Sara A. Gagné ◽  
Peter J. Sherman ◽  
Kunwar K. Singh ◽  
Ross K. Meentemeyer

2018 ◽  
Author(s):  
Jin-Yong Kim ◽  
Sanghun Lee ◽  
Man-Seok Shin ◽  
Chang-Hoon Lee ◽  
Changwan Seo ◽  
...  

Altitudinal patterns in the population ecology of mountain bird species are useful for predicting species occurrence and behavior. Numerous hypotheses about the complex interactions among environmental factors have been proposed; however, these remain controversial. This study investigated the causes of altitudinal patterns in breeding bird species richness and density in relation to climate, habitat heterogeneity, and migration influence in Jirisan National Park, South Korea. We conducted a field survey of 142 plots at altitudes between 200 and 1400 m above mean sea level in the breeding season. A total of 2771 individuals from 53 breeding bird species were recorded. Altitudinal patterns of species richness and density showed a hump-shaped pattern, indicating that the highest richness and density could be observed at moderate altitudes. Models constructed with 16 combinations of six variables demonstrated that species richness was positively correlated with vertical and horizontal habitat heterogeneity, and that density was positively correlated with vertical, but not horizontal, habitat heterogeneity, and negatively correlated with migrant rate. No significant relationships were found between spring temperature and species richness or density. Therefore, the observed patterns in species richness support the hypothesis that habitat heterogeneity, rather than climate, is the main driver of species richness. And neither habitat heterogeneity nor climate hypotheses fully explains the observed patterns in density. However, vertical habitat heterogeneity does likely help explain observed patterns in density. The heterospecific attraction hypothesis did not apply to the distribution of birds along the altitudinal gradient. Appropriate management of vertical habitat heterogeneity, such as vegetation cover, should be maintained for the conservation of bird diversity in this area.


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