Agriculture, water mismanagement and ecosystem transformations in the Cuatrociénegas Valley in the Chihuahuan Desert, Mexico

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1 Agriculture, water mismanagement and ecosystem transformations in the Cuatrociénegas Valley in the Chihuahuan Desert, Mexico Irene Pisanty María Cristina Pérez y Sosa Gabriel Gálvez Departamento de Ecología y Recursos Naturales Facultad de Ciencias UNAM

2 Cuatrociénegas, Coahuila

4 climate Rainfall (mm) Temperature ( C) Oct oct Jan ene Feb feb Mar mar Apr abril May may Jun junio July julio Aug agost Sept sept Oct Nov oct nov Dec Jan dic ene BWh Time ( ) Precipitation (mm) Rainfall (mm) Temperature ( C) 0.0 Jan Feb March April May Jun July Agust Sept Oct Nov Dec 0.0 Time (20 years)

5 Ecological importance of the Cuatrociénegas Valley Plants 860 species 23 endemic species Animals 250 species 56 endemic species

6 Different microenvironments Water bodies spring heads ponds streams terminal lakes complex underground water system Riparian vegetation Halophilous vegetation Gypsum dunes Desertic shrublands

8 .

13 Churince System sampling area 1. Poza Churince 2. Poza Bonita 3. Laguna Intermedia 4. Laguna Churince (Laguna Grande) 5. Río Churince Poza Churince and Poza Bonita are connected underground.

14 Poza Bonita

15 Poza Churince

16 Laguna intermedia

17 Water level Poza Bonita average water level Level (m) April-07 June-07 Agust-07 Oct-07 Dec- 07 Feb-08 April-08 June-08 Agust-08 Oct-08 Dec- 08 Feb-09 April-09 June-09 Agust-09 Time Poza Churice average water level water level (m) Dec-06 Feb-07 April-07 June-07 Agust-07 Oct-07 Dec-07 Feb-08 April-08 June-08 Agust-08 Nov-08 Jan-09 March-09 May-09 July-09 time

18 Laguna Churince 1973

19 Laguna Churince 1977

20 Laguna Churince 1986

21 1990

22 1992

23 1996

24 2000

25 2004

26 2006

27 Laguna Churince: disappearing is a fact Pérdida de superficie de Laguna Churince Superficie (m²) Años

28 changes a b c d

29 Not many measurments, but.

30 El Hundido

35 Measuring parameters depth water level length width

36 Percentages of sinkholes with and without water 100% 90% 80% 70% 60% 50% 40% with water without water 30% 20% 10% 0% January 08 March May July September November January 09 time

37 Meses cálidos Figura 9. Dinámica de abras: número total y formación de abras nuevas

38 Sinkholes: size categories Warm months Sinkoholes (%) Oct Jan Mar May June Aug Oct Dec Time

39 Annual transition probabilities for sinkholes categorized by size (area) General annual transition probabilities Permanence Growth to next category Growth to following categories Retrogression 0.053

40 Projected size structure of sinkholes in the Churince System Sinkholes (%) Time (years)

41 species in sinkholes

42 Vegetation strips

43 Samolus ebractetus var. coahuilensis

44 A brave colonizer

45 Samolus ebracteatus var. coahuilensis Green rosettes inflorescence Dry rosettes

46 growth Branches (rosettes) Underground meristems rizome root

48 Ramet (physologically independent)

49 Structure of the population of S. ebracteatus, based on size categories

50 Fecundity Category Reproductive individuals Average number of seeds Individuals per category (March 2009)

51 Matriz anual de transición (mar 08 mar 09)

52 Life cycle diagram of Samolus ebracteatus

53 Some conclusions Sinkholes of different sizes will probably continue to form as long as water continues to flow from Rio Churince towards the flatland that surrounds it, probably caused by an unstable underground system This process is related to the decrease of the water flow from Poza Churince The decrease seems to be related with underwater destabilization due to water overexploitation in the reserve and in the surrounding valleys

54 The projection model shows that, if the conditions prevailing when we started this study persist in time, the water bodies of the Churince System will be surrounded by big soil depressions that will be colonized by species that can both take advantage of the humidity these riparian habitats offer, and tolerate high salinity levels.

55 In other words, the loss of water from the stream and the resulting formation of sinkholes will eventually transform this area into a set of big holes resulting from a general destabilization of the water system and the soil, which will collapse repeatedly and constantly. However, the process of sinkhole formation could decrease progressively if the different parts of the system continue to dry through time

56 Sinkhole formation can be used as an early warning system for underground water variations implying the loss of surface water Some species, as Samolus ebractatus are indicators of humid microhabitats; changes in their distribution, abundance and population dynamics are indicators of variation in physical parameters

57 Water bodies 1990

58 Water bodies 2000

59 No doubt Even if the terminal causes of this process are still being determined (and discussed), urgent action is needed to preserve the wetlands in this extraordinary system

60 Irene Pisanty tel +52(55) Gracias! Thank you!

61 Riqueza Composición específica Nomenclatura Familia Especie Se Primulaceae Samolus ebracteatus Perenne Bm Cyperaceae Bolboschoenus maritimus Perenne Jp Poaceae Jouvea pilosa Perenne Fc Asteraceae Flaveria chlorifola Perenne Jc Asteraceae Jaumea carnosa. Perenne Sc Poaceae Sporobolus coahuilensis. Perenne A Fabaceae Acacia sp Perenne St Gentianaceae Sabatia tuberculosa Anual Ee Gentianaceae Eustoma exaltatum Anual

January 2018 Air Traffic Activity Summary

January 2018 Air Traffic Activity Summary Jan-2018 Jan-2017 CY-2018 CY-2017 Passengers 528,947 505,421 4.7% 528,947 505,421 4.7% Passengers 537,332 515,787 4.2% 537,332 515,787 4.2% Passengers 1,066,279