The Navajo man (native-american) in this photograph is wearing the costume of Tonenili, the God of Water, for a ceremony called the night chant or Yebichai. His costume is made of spruce tree branches and a mark. c. 1904. 

Photographer: by Edward S. Curtis.

Via: @archaeologyart

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Functional traits driving pollinator and predator responses to newly established grassland strips in agricultural landscapes 

Maas et al., 2021.

 

1. Agricultural biodiversity and associated ecosystem functions are declining at alarming rates due to widespread land use intensification. They can only be maintained through targeted landscape management that supports species with different habitat preferences, dispersal capacities and other functional traits that determine their survival. However, we need better understanding whether short-term measures can already improve functional diversity in European agroecosystems.
2. We investigated spatio-temporal responses of bees (solitary bees, bumblebees and honey bees), hoverflies, carabid beetles and spiders to newly established grassland strips in Lower Austria over 3 years, and along a distance gradient to old grasslands. Specifically, we asked if new grasslands, compared to old grasslands and cereal fields, serve as temporal dispersal habitat or corridor, and how species-specific traits affect dispersal patterns. Using a trait-based functional diversity approach, we investigated year and distance effects for nine selected key traits per taxon (e.g. body size, feeding guild and habitat preferences).
3. Our results show that the functional diversity of predators and pollinators (i.e. functional richness and evenness), as well as community-weighted means of selected key traits in new grasslands significantly differed from adjacent cereal fields, but only slowly adjusted to adjacent old grasslands. These effects significantly decreased with increasing distance to old grasslands for carabids and spiders, but not for mobile bees and hoverflies.
4. Synthesis and applications. Over 3 years, newly established grassland strips supported larger sized and actively foraging/hunting species in the agricultural landscape. Adjacent crops likely benefit from such measures through enhanced functional diversity and related ecosystem services. However, our results also suggest that 3-year period is too short to enhance the occurrence of pollinators and epigeic predators in new grasslands. Agri-environment measures need to be complemented by the conservation of permanent habitats to effectively maintain species and functional diversity. Our findings should be acknowledged by European policy and agricultural decision makers for the design of more effective agri-environment schemes, taking into account trait-dependent species responses to land use change. 

Effects of habitat types on functional richness and functional evenness of (a) carabids, (b) spiders, (c) bees and (d) hoverflies in old grasslands (OG), newly established grasslands (NG), nearby cereal fields (CN) and far distanced cereal fields (CF). Original data points are indicated by grey circles and significance levels due not differ between groups according to lmer and Tukey post hoc tests.

 https://doi.org/10.1111/1365-2664.13892

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“What escapes the eye …is a much more insidious kind of extinction: the extinction of ecological interactions.”

 

Daniel Janzen 

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Can agroecology improve food security and nutrition? 

Kerr et al., 2021

- 56 agroecology studies had evidence for food security & nutrition (FSN) outcomes.

- 78% of studies showed positive FSN outcomes from agroecological practices.

- Key agroecological practices are crop diversity, organic soil amendments, and agroforestry.

- Farmer networks and attention to social equity dimensions were important.

- Increased complexity of agroecological system more positively associated with FSN.

Agroecology increasingly has gained scientific and policy recognition as having potential to address environmental and social issues within food production, but concerns have been raised about its implications for food security and nutrition, particularly in low-income countries. This review paper examines recent evidence (1998–2019) for whether agroecological practices can improve human food security and nutrition. A total of 11,771 articles were screened by abstract and title, 275 articles included for full review, with 56 articles (55 cases) selected. A majority of studies (78%) found evidence of positive outcomes in the use of agroecological practices on food security and nutrition of households in low and middle-income countries. Agroecological practices included crop diversification, intercropping, agroforestry, integrating crop and livestock, and soil management measures. More complex agroecological systems, that included multiple components (e.g., crop diversification, mixed crop-livestock systems and farmer-to-farmer networks) were more likely to have positive food security and nutrition outcomes. 

https://doi.org/10.1016/j.gfs.2021.100540

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The Moment

The moment when, after many years 
of hard work and a long voyage 
you stand in the centre of your room, 
house, half-acre, square mile, island, country, 
knowing at last how you got there, 
and say, I own this, 

is the same moment when the trees unloose 
their soft arms from around you, 
the birds take back their language,

the cliffs fissure and collapse, 

the air moves back from you like a wave 

and you can't breathe. 

No, they whisper. You own nothing. 
You were a visitor, time after time 
climbing the hill, planting the flag, proclaiming. 
We never belonged to you. 
You never found us. 
It was always the other way round.

Margaret Atwood (1998) Eating Fire

An Ecological Insight into the Multifaceted World of Plant-Endophyte Association 

Sushma Mishra, Annapurna Bhattacharjee & Shilpi Sharma, 2021

Under natural conditions plants are not individual entities; they are associated with diverse microbiota to form the plant holobiont. The concept of plant holobiont is being actively explored to address the issues related to plant’s health. Endophytes are a class of plant-associated microbes, which reside within the internal tissues of plants. They have been ubiquitously reported in all plants investigated so far. The plant-endophyte interactions may exhibit different modes of symbiotic association, ranging from beneficial (mutualism), neutral (commensal), to even pathogenic. Although we have a fair idea of the factors affecting plant-microbe interactions, the intricacies involved in fine-tuning their association are just beginning to unfold. Some of the pertinent questions surrounding the plant-endophyte symbiosis include: how are endophytes different from other beneficial microbes like rhizobia, mycorrhizae, and rhizobacteria? What mechanisms ensure that endophytes gain an unsurpassed entry and colonization into plants without eliciting a strong defense reaction? Why do different strains of the same microbial species enter into diverse modes of symbiotic association with plants? What factors cause the switch in the lifestyle of endophytes? In the present review, these questions have been addressed in the light of recent data and finally, concluded with gaps in endophyte research, which could be deliberated in future endeavors.

https://www.tandfonline.com/doi/full/10.1080/07352689.2021.1901044

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In memoriam  

Richard Lewontin (1929 - 2021)  

"Parts and wholes evolve in consequence of their relationship, and the relationship itself evolves"

Fundamentos Teóricos del Manejo Ecológico de Plagas y Enfermedades  

(una aproximación biomatemática) 

 

 

Curso libre: https://bit.ly/2IYmDVT

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