Study in Spain Confirms Olive Tree as Strategic Crop to Recover Biodiversity

The dis­cov­ery of a new botan­i­cal species dur­ing a research study con­ducted in Andalusia attests that even though olive groves have lost a lot of their bio­di­ver­sity in the past few decades, they remain a solid flora and fauna foun­da­tion that makes them an ideal plat­form to recover bio­di­ver­sity, an added-value of olive and olive oil pro­duc­tion.

The find­ings were part of Olive Alive’s LIFE Project, an ini­tia­tive coor­di­nated by SEO/BirdLife and con­ducted by the University of Jaén and Spain’s Higher Council for Scientific Research (CSIC) through 40 olive groves in 20 Andalusian loca­tions.

The study, results were unveiled this month, was con­ceived to quan­tify diver­sity as a basis for future assess­ments of the impact of actions imple­mented to recover bio­di­ver­sity. It demon­strated that bio­di­ver­sity can be a good invest­ment that can con­tribute to a greater prof­itabil­ity in olive cul­ti­va­tion and oil pro­duc­tion and must, there­fore, be con­sid­ered when devel­op­ing new agri­cul­tural poli­cies and prac­tices.

Linaria qar­to­ben­sis was the botan­i­cal species dis­cov­ered in an olive grove in Córdoba. It dis­plays dif­fer­ent traits than other Linaria species, such as shape, color and seeds, and has now been included in Spanish and global reg­istries. A total of 549 herba­ceous species and 137 woody species were reg­is­tered through the study.

On the ani­mal side, 165 bird species from 199 gen­era were iden­ti­fied dur­ing the study. Olive groves serve as their habi­tat for nest­ing, hiber­na­tion or as tran­sit dur­ing migra­tion. Twenty-six of the species had some sort of men­aced sta­tus, includ­ing two in dan­ger of extinc­tion: red alza­cola and great bus­tard (Otis tarda.) One hun­dred nine­teen pol­li­na­tor insects and 58 ant species were also reg­is­tered, one among which appears to be a species con­sid­ered extinct since 1960, Aphaenogaster gemella.

The fig­ures rep­re­sent an aver­age between all olive groves stud­ied as bio­di­ver­sity is not homoge­nous through them all, vary­ing depend­ing on the man­age­ment of soil, the appli­ca­tion of con­ven­tional or bio­log­i­cal agri­cul­ture prac­tices, the size of the plots, and the com­plex­ity of the land­scape.

Simple land­scapes were those where olive trees pre­dom­i­nated with a lim­ited pres­ence of other crops; land­scapes of inter­me­di­ate com­plex­ity were those in which olive trees are inter­twined with other crops and other veg­e­ta­tive ele­ments; and com­plex land­scapes were places where olive groves were not nec­es­sar­ily dom­i­nant, coex­ist­ing with a great array of other veg­e­tal ele­ments.

Olive groves were sam­pled and indexed in terms of their exten­sion, cul­ti­va­tion meth­ods, func­tional diver­sity, het­ero­gene­ity, rela­tion­ship with the land­scape, and value for preser­va­tion. A list of species, gen­era and fam­i­lies of each group of organ­isms used as bio­di­ver­sity indi­ca­tors was cre­ated for each grove sam­pled and maps delin­eat­ing the uses of each ter­ri­tory were also pre­pared. The aggre­gate sam­ple rep­re­sented a lit­tle less than 10,000 hectares from a total olive grove sur­face of 1.5 mil­lion hectares in Andalusia. Samples were obtained from April 2016 through May 2017.

The loss of bio­di­ver­sity in Spain began in the late 1980s when mass-pro­duc­tion agri­cul­tural prac­tices were adopted because of the country’s incor­po­ra­tion into the European Union’s Common Agrarian Policy. This sim­pli­fied cul­ti­va­tion elim­i­nated all ele­ments not strictly related to olive trees, a destruc­tion accom­plished mostly with pes­ti­cides and her­bi­cides. This not only con­tributed to a sig­nif­i­cant loss of bio­di­ver­sity but over time led to expos­ing crops to evolv­ing pathogens.

Biodiversity con­tributes to soil fer­til­ity and to con­trol ero­sion, plagues, and dis­eases. Olive Alive seeks to rein­tro­duce bio­di­ver­sity into olive groves to increase their prof­itabil­ity by devis­ing grow­ing mod­els that help improve the qual­ity of olive oils and are com­pat­i­ble with the preser­va­tion of ecosys­tems.

Some actions pro­posed towards this end include the man­age­ment of herba­ceous cov­ers and the restora­tion of unpro­duc­tive zones through the plant­ing of spe­cific trees, bushes, and herbs, along with the cre­ation of func­tional ele­ments to shel­ter ani­mals favor­able to bio­di­ver­sity.

Earlier this 2018, SEO/BirdLife began its par­tic­i­pa­tion in a two-year col­lab­o­ra­tive project that will study herba­ceous cov­ers of native species in olive groves, in an attempt to trans­fer knowl­edge about sus­tain­able prac­tices through demon­stra­tive tri­als in the groves, also con­sol­i­dat­ing agro­nom­i­cal tools for soil man­age­ment that can help con­trol ero­sion, main­tain fer­til­ity and pre­serve bio­di­ver­sity.

• Olivares Vivos


• Europa Press