A. Azua-Bustos, A. G. Fairén, C. González-Silva, C. Ascaso, D. Carrizo, M. Á. Fernández-Martínez, M. Fernández-Sampedro, L. García-Descalzo, M. García-Villadangos, M. P. Martin-Redondo, L. Sánchez-García, J. Wierzchos & V. Parro. 2018. Unprecedented rains decimate surface microbial communities in the hyperarid core of the Atacama Desert. Scientific Reports 8, DOI: 10.1038/s41598-018-35051-w
The hyperarid core of the Atacama Desert, the driest and oldest desert on Earth, has experienced a number of highly unusual rain events over the past three years, resulting in the formation of previously unrecorded hypersaline lagoons, which have lasted several months. We have systematically analyzed the evolution of the lagoons to provide quantitative field constraints of large-scale impacts of the rains on the local microbial communities. Here we show that the sudden and massive input of water in regions that have remained hyperarid for millions of years is harmful for most of the surface soil microbial species, which are exquisitely adapted to survive with meager amounts of liquid water, and quickly perish from osmotic shock when water becomes suddenly abundant. We found that only a handful of bacteria, remarkably a newly identified species of Halomonas, remain metabolically active and are still able to reproduce in the lagoons, while no archaea or eukaryotes were identified. Our results show that the already low microbial biodiversity of extreme arid regions greatly diminishes when water is supplied quickly and in great volumes. We conclude placing our findings in the context of the astrobiological exploration of Mars, a hyperarid planet that experienced catastrophic floodings in ancient times.
A. Azua-Bustos, A. G. Fairén, C. González-Silva, C. Ascaso, D. Carrizo, M. Á. Fernández-Martínez, M. Fernández-Sampedro, L. García-Descalzo, M. García-Villadangos, M. P. Martin-Redondo, L. Sánchez-García, J. Wierzchos & V. Parro. 2018 - 2018 - Mfano wa Utafiti Mvua zisizotarajiwa huangamiza jamii za viini vilivyo juu ya ardhi katika eneo kavu sana la Jangwa la Atacama. "Kulingana na ripoti ya utafiti wa Utafiti wa Sayansi ya Dunia (Scientific Reports 8, DOI 10.1038-4159-818-35051) ""Msingi wa kavu wa Jangwa la Atacama, jangwa kavu na la zamani zaidi duniani, umepata matukio kadhaa ya mvua isiyo ya kawaida katika miaka mitatu iliyopita, na kusababisha kuundwa kwa mabwawa ya chumvi ambayo hayajawahi kurekodiwa hapo awali." Kwa mfano, tulichunguza kwa utaratibu jinsi mabwawa hayo yalivyobadilika ili kupata habari kuhusu athari za mvua hizo kwa jamii za wadudu. "Hapa tunaonyesha kwamba ""kuingia kwa maji kwa ghafula na kwa wingi katika maeneo ambayo yamebaki kuwa kavu sana kwa mamilioni ya miaka ni hatari kwa spishi nyingi za wadudu wa udongo wa uso, ambao wamebadilika sana kuishi na kiasi kidogo cha maji ya kioevu, na kupotea haraka kutokana na mshtuko wa osmotic wakati maji yanapokuwa mengi ghafla.""" "Wanasayansi wamegundua kwamba bakteria chache tu, aina mpya ya Halomonas, bado zinafanya kazi na zina uwezo wa kuzaliana katika mabwawa, wakati hakuna ""archaea"" au ""eukaryotes"" zilizotambuliwa." Matokeo yetu yanaonyesha kwamba utofauti wa viumbe wa asili wa maeneo ya ukame wa hali ya juu hupungua sana wakati maji yanapotolewa haraka na kwa kiasi kikubwa. "Tunahitimisha kwa kuweka matokeo yetu katika muktadha wa uchunguzi wa astrobiolojia wa Mars, sayari ya hyperarid ambayo ilipata mafuriko mabaya katika nyakati za kale. """