## Loading required package: readxl
## Loading required package: lubridate
## 
## Attaching package: 'lubridate'
## The following objects are masked from 'package:data.table':
## 
##     hour, isoweek, mday, minute, month, quarter, second, wday, week,
##     yday, year
## The following objects are masked from 'package:base':
## 
##     date, intersect, setdiff, union
## Loading required package: solartime
## - Winter data excluded.
## - The counts of all passing / wintering species (not resident nor breeding in the sampled unit) were set to zero. Abreed_and_non_breed contains the non-breeders as well.

Loess covered areas in the northern Negev

Factors are land use (KKL plantings, Bedouine agriculture and natural loess) and time. Total 5 campaigns, one of which is pilot in 2012 which does not contain the bedouin agriculture land use level. 3 levels of land use: KKL plantings: 5 campaigns 2012-2020, 9 plots in each campaign. Bedouin agriculture: 4 campaigns 2014-2020, plot numbers: 9, 11, 12 ,12 respective to years. Loess: 5 campaigns 2012-2020, plot numbers: 15,9,9,9,9 respective to years. Year 2012 had 3 sites that were not repeated: Goral (3 plots), Hatzerim Base (6 plots), Nevatim Base (3 plots). If need to throw out data, best is to throw out Nevatim and the 3 plots named Hatzerim Loess 1,2,3 (have low / outlying counts of biodiversity metrics). 5 sites with 9 plots per site (3 for each land use X proximity combination).

Raw data Total abundance: 6040 Number of observations: 1447 Total richness: 92

Filtered data Total abundance: 2448 Number of observations: 780 Total richness: 41

Model gma, abundance and richness

Richness done with rare species. Abundance and mean abundance done without rare species. Full models include cosine and sine of the time difference from June 21st (in radians).

richness

Explore data.

## [1] "RICHNESS WITH RARE SPECIES"
## [1] "data with 2012"
## ℹ SHA-1 hash of file is "eef55df1963ba201f57cf44513f566298756fd4f"

## [1] "data without 2012"

## [1] "data with 2012"

## [1] "data without 2012"
richness year_ct site land_use td_sc cos_td_rad sin_td_rad h_from_sunrise cos_hsun sin_hsun monitors_name wind precipitation temperature clouds
Min. : 1.000 Min. :0.000 Sayeret Shaked :30 Loess :51 Min. :-1.5653 Min. :0.02295 Min. :-0.9997 Length:140 Min. :0.1951 Min. :-0.1642 Eyal Shochat : 30 0 : 0 0 : 0 0 : 0 0 : 0
1st Qu.: 3.000 1st Qu.:2.000 Nahal Ashan :24 Bedouin Agriculture:44 1st Qu.:-0.7244 1st Qu.:0.34157 1st Qu.:-0.9201 Class :difftime 1st Qu.:0.8607 1st Qu.: 0.1331 Adi Domer : 0 1 : 0 3 : 0 1 : 0 1 : 0
Median : 4.000 Median :4.000 Mishmar Hanegev:23 KKL Plantings :45 Median : 0.6826 Median :0.85208 Median :-0.5087 Mode :numeric Median :0.9542 Median : 0.2990 Asaf Mayrose : 0 2 : 0 NA’s:140 2 : 0 2 : 0
Mean : 4.593 Mean :4.214 Givot Goral :15 NA Mean : 0.6387 Mean :0.67279 Mean :-0.4482 NA Mean :0.8921 Mean : 0.3286 Eliraz Dvir : 0 3 : 0 NA 3 : 0 3 : 0
3rd Qu.: 6.000 3rd Qu.:6.000 Eshel Hanasi :12 NA 3rd Qu.: 1.5220 3rd Qu.:0.90882 3rd Qu.:-0.1543 NA 3rd Qu.:0.9893 3rd Qu.: 0.5090 Eliraz Dvir and Yoav Barak: 0 NA’s:140 NA NA’s:140 NA’s:140
Max. :15.000 Max. :8.000 Givot Bar :12 NA Max. : 4.9558 Max. :1.00000 Max. : 0.9845 NA Max. :1.0000 Max. : 0.9808 (Other) : 0 NA NA NA NA
NA NA (Other) :24 NA NA NA NA NA NA’s :51 NA’s :51 NA’s :110 NA NA NA NA

no observation for all 4 weather variables. many NAs for sampling time of day variables.exclude from model.

## Warning in cor(P.anal[, lapply(X = .SD, FUN = as.numeric), .SDcols =
## IVs[1:11]], : the standard deviation is zero
richness year_ct site land_use td_sc cos_td_rad sin_td_rad h_from_sunrise cos_hsun sin_hsun monitors_name
richness 1.0000000 0.0358986 -0.2439373 0.3623180 -0.0031931 0.1716892 -0.0409555 -0.1092363 0.1844295 -0.0750554 NA
year_ct 0.0358986 1.0000000 -0.0131923 0.0784319 -0.6891876 -0.4527528 -0.6804369 -0.1097558 0.1168999 -0.1052239 NA
site -0.2439373 -0.0131923 1.0000000 -0.1194452 -0.1113288 -0.1171673 -0.0980130 0.1422600 -0.0542126 0.1561513 NA
land_use 0.3623180 0.0784319 -0.1194452 1.0000000 -0.0996863 0.0851086 -0.1008691 -0.0772346 0.1350010 -0.0453437 NA
td_sc -0.0031931 -0.6891876 -0.1113288 -0.0996863 1.0000000 0.5324060 0.9841321 0.0203523 -0.1285853 -0.0237796 NA
cos_td_rad 0.1716892 -0.4527528 -0.1171673 0.0851086 0.5324060 1.0000000 0.4312002 0.0061055 -0.1126261 -0.0359190 NA
sin_td_rad -0.0409555 -0.6804369 -0.0980130 -0.1008691 0.9841321 0.4312002 1.0000000 0.0492202 -0.1557296 0.0031361 NA
h_from_sunrise -0.1092363 -0.1097558 0.1422600 -0.0772346 0.0203523 0.0061055 0.0492202 1.0000000 -0.9303548 0.9897728 NA
cos_hsun 0.1844295 0.1168999 -0.0542126 0.1350010 -0.1285853 -0.1126261 -0.1557296 -0.9303548 1.0000000 -0.8708307 NA
sin_hsun -0.0750554 -0.1052239 0.1561513 -0.0453437 -0.0237796 -0.0359190 0.0031361 0.9897728 -0.8708307 1.0000000 NA
monitors_name NA NA NA NA NA NA NA NA NA NA NA

Fit Poisson glm, check for existence of overdispersion

## [1] "Estimating overdispersion parameter phi: (Res. Dev.)/(n-p) where n=number of observations; p=number of parameters in the model."
## [1] "od = 0.760798125335199"

Overdispersion parameter is < 1. Poisson more appropriate. Compare Poisson and negative binomial.

## Warning in theta.ml(Y, mu, sum(w), w, limit = control$maxit, trace =
## control$trace > : iteration limit reached

## Warning in theta.ml(Y, mu, sum(w), w, limit = control$maxit, trace =
## control$trace > : iteration limit reached
##       df      AIC
## m0.po 16 586.8881
## m0.nb 17 588.8897
## [1] "poisson"

## [1] "neg bin"

negative binomial did not converge because there is underdispersion and poisson is better.

go with mixed model.

## Generalized linear mixed model fit by maximum likelihood (Laplace
##   Approximation) [glmerMod]
##  Family: poisson  ( log )
## Formula: richness ~ land_use * year_ct + cos_td_rad + sin_td_rad + (1 |  
##     site)
##    Data: P.anal
## 
##      AIC      BIC   logLik deviance df.resid 
##    588.5    615.0   -285.2    570.5      131 
## 
## Scaled residuals: 
##     Min      1Q  Median      3Q     Max 
## -1.6859 -0.6177 -0.1608  0.5767  3.6774 
## 
## Random effects:
##  Groups Name        Variance Std.Dev.
##  site   (Intercept) 0.01245  0.1116  
## Number of obs: 140, groups:  site, 9
## 
## Fixed effects:
##                                     Estimate Std. Error z value Pr(>|z|)    
## (Intercept)                          1.06782    0.17914   5.961 2.51e-09 ***
## land_useBedouin Agriculture         -0.26481    0.23580  -1.123   0.2614    
## land_useKKL Plantings                0.32321    0.16197   1.995   0.0460 *  
## year_ct                             -0.01841    0.03094  -0.595   0.5518    
## cos_td_rad                           0.37660    0.16078   2.342   0.0192 *  
## sin_td_rad                          -0.09158    0.13362  -0.685   0.4931    
## land_useBedouin Agriculture:year_ct  0.10169    0.04355   2.335   0.0195 *  
## land_useKKL Plantings:year_ct        0.01537    0.03572   0.430   0.6670    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Correlation of Fixed Effects:
##             (Intr) lnd_BA ln_KKLP yer_ct cs_td_ sn_td_ l_BA:_
## lnd_sBdnAgr -0.222                                           
## lnd_sKKLPln -0.297  0.383                                    
## year_ct     -0.492  0.269  0.454                             
## cos_td_rad  -0.730 -0.160 -0.208   0.083                     
## sin_td_rad   0.147  0.013  0.144   0.403 -0.267              
## lnd_sBAgr:_  0.202 -0.805 -0.321  -0.534  0.123  0.043       
## lnd_sKKLP:_  0.233 -0.259 -0.735  -0.659  0.147 -0.061  0.492

perform stepwise model selection of poisson mixed model.

## Single term deletions
## 
## Model:
## richness ~ land_use * year_ct + cos_td_rad + sin_td_rad + (1 | 
##     site)
##                  npar    AIC
## <none>                588.49
## cos_td_rad          1 592.12
## sin_td_rad          1 586.97
## land_use:year_ct    2 590.59

remove sine of time of year.

## Single term deletions
## 
## Model:
## richness ~ land_use * year_ct + cos_td_rad + (1 | site)
##                  npar    AIC
## <none>                586.97
## cos_td_rad          1 590.14
## land_use:year_ct    2 589.43

land_use * year and cosine of time of year remain. Final model:

## Generalized linear mixed model fit by maximum likelihood (Laplace
##   Approximation) [glmerMod]
##  Family: poisson  ( log )
## Formula: richness ~ land_use * year_ct + cos_td_rad + (1 | site)
##    Data: P.anal
## 
##      AIC      BIC   logLik deviance df.resid 
##    587.0    610.5   -285.5    571.0      132 
## 
## Scaled residuals: 
##     Min      1Q  Median      3Q     Max 
## -1.6438 -0.6020 -0.1577  0.5573  3.6664 
## 
## Random effects:
##  Groups Name        Variance Std.Dev.
##  site   (Intercept) 0.01149  0.1072  
## Number of obs: 140, groups:  site, 9
## 
## Fixed effects:
##                                      Estimate Std. Error z value Pr(>|z|)    
## (Intercept)                          1.083714   0.174602   6.207 5.41e-10 ***
## land_useBedouin Agriculture         -0.263209   0.234868  -1.121   0.2624    
## land_useKKL Plantings                0.339773   0.160606   2.116   0.0344 *  
## year_ct                             -0.009524   0.027935  -0.341   0.7332    
## cos_td_rad                           0.348352   0.154097   2.261   0.0238 *  
## land_useBedouin Agriculture:year_ct  0.102878   0.043278   2.377   0.0174 *  
## land_useKKL Plantings:year_ct        0.013666   0.035496   0.385   0.7002    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Correlation of Fixed Effects:
##             (Intr) lnd_BA ln_KKLP yer_ct cs_td_ l_BA:_
## lnd_sBdnAgr -0.223                                    
## lnd_sKKLPln -0.321  0.389                             
## year_ct     -0.608  0.294  0.438                      
## cos_td_rad  -0.720 -0.173 -0.191   0.203              
## lnd_sBAgr:_  0.196 -0.811 -0.332  -0.602  0.148       
## lnd_sKKLP:_  0.242 -0.265 -0.737  -0.693  0.147  0.494
## $site
##                  (Intercept)
## Eshel Hanasi    -0.045137191
## Givot Bar        0.002827638
## Givot Goral      0.106788644
## Hatzerim Base   -0.001968742
## Mishmar Hanegev  0.075006970
## Nahal Ashan      0.065199853
## Nevatim Base     0.005947562
## Park Loess      -0.093317558
## Sayeret Shaked  -0.103992836
## 
## with conditional variances for "site"
## $site

## Registered S3 methods overwritten by 'broom':
##   method            from  
##   tidy.glht         jtools
##   tidy.summary.glht jtools
Observations 140
Dependent variable richness
Type Mixed effects generalized linear model
Family poisson
Link log
AIC 586.971
BIC 610.504
Pseudo-R² (fixed effects) 0.187
Pseudo-R² (total) 0.231
Fixed Effects
exp(Est.) S.E. z val. p
(Intercept) 2.956 0.175 6.207 0.000
land_useBedouin Agriculture 0.769 0.235 -1.121 0.262
land_useKKL Plantings 1.405 0.161 2.116 0.034
year_ct 0.991 0.028 -0.341 0.733
cos_td_rad 1.417 0.154 2.261 0.024
land_useBedouin Agriculture:year_ct 1.108 0.043 2.377 0.017
land_useKKL Plantings:year_ct 1.014 0.035 0.385 0.700
Random Effects
Group Parameter Std. Dev.
site (Intercept) 0.107
Grouping Variables
Group # groups ICC
site 9 0.011

Test whether temporal trends are significantly different from zero, using emmeans package, FDR correction for multiple comparisons.

##  land_use            year_ct.trend     SE  df z.ratio p.value
##  Loess                    -0.00952 0.0279 Inf  -0.341  0.8725
##  Bedouin Agriculture       0.09335 0.0346 Inf   2.698  0.0209
##  KKL Plantings             0.00414 0.0258 Inf   0.161  0.8725
## 
## P value adjustment: fdr method for 3 tests

Test for pairwise differences among levels of land use, apply FDR correction for multiple comparisons.

##  contrast                            year_ct estimate    SE  df z.ratio p.value
##  Loess - Bedouin Agriculture            4.21   -0.170 0.138 Inf  -1.239  0.2154
##  Loess - KKL Plantings                  4.21   -0.397 0.113 Inf  -3.521  0.0013
##  Bedouin Agriculture - KKL Plantings    4.21   -0.227 0.116 Inf  -1.959  0.0751
## 
## Results are given on the log (not the response) scale. 
## P value adjustment: fdr method for 3 tests

Significant increase of 9.7850508% in richness per year on average for Bedouin agriculture, no significant temporal trend for Loess and KKL Plantings.

on average over time, Loess richness (3.589255 species) is significantly lower than KKL (5.340458 species; P=0.001); Bedouin agriculture (4.2558382 species) is not significantly different from both of them.

geometric mean of abundance

Explore data. Exclude time of day because of high number of NAs.

## [1] "GEOMETRIC MEAN ABUNDANCE WITHOUT RARE SPECIES"
## [1] "data with 2012"

## [1] "data without 2012"

## [1] "data with 2012"

## [1] "data without 2012"
gma year_ct site land_use td_sc cos_td_rad sin_td_rad h_from_sunrise cos_hsun sin_hsun monitors_name wind precipitation temperature clouds
Min. : 1.260 Min. :0.000 Sayeret Shaked :30 Loess :51 Min. :-1.5653 Min. :0.02295 Min. :-0.9997 Length:140 Min. :0.1951 Min. :-0.1642 Eyal Shochat : 30 0 : 0 0 : 0 0 : 0 0 : 0
1st Qu.: 2.000 1st Qu.:2.000 Nahal Ashan :24 Bedouin Agriculture:44 1st Qu.:-0.7244 1st Qu.:0.34157 1st Qu.:-0.9201 Class :difftime 1st Qu.:0.8607 1st Qu.: 0.1331 Adi Domer : 0 1 : 0 3 : 0 1 : 0 1 : 0
Median : 2.406 Median :4.000 Mishmar Hanegev:23 KKL Plantings :45 Median : 0.6826 Median :0.85208 Median :-0.5087 Mode :numeric Median :0.9542 Median : 0.2990 Asaf Mayrose : 0 2 : 0 NA’s:140 2 : 0 2 : 0
Mean : 2.926 Mean :4.214 Givot Goral :15 NA Mean : 0.6387 Mean :0.67279 Mean :-0.4482 NA Mean :0.8921 Mean : 0.3286 Eliraz Dvir : 0 3 : 0 NA 3 : 0 3 : 0
3rd Qu.: 3.207 3rd Qu.:6.000 Eshel Hanasi :12 NA 3rd Qu.: 1.5220 3rd Qu.:0.90882 3rd Qu.:-0.1543 NA 3rd Qu.:0.9893 3rd Qu.: 0.5090 Eliraz Dvir and Yoav Barak: 0 NA’s:140 NA NA’s:140 NA’s:140
Max. :10.371 Max. :8.000 Givot Bar :12 NA Max. : 4.9558 Max. :1.00000 Max. : 0.9845 NA Max. :1.0000 Max. : 0.9808 (Other) : 0 NA NA NA NA
NA NA (Other) :24 NA NA NA NA NA NA’s :51 NA’s :51 NA’s :110 NA NA NA NA

Fit glm, compare gamma, gaussian (poisson inappropriate because response is not discrete)

Gamma seems better than gaussian. Fit fixed and mixed models.

## Warning in checkConv(attr(opt, "derivs"), opt$par, ctrl = control$checkConv, :
## Model failed to converge with max|grad| = 0.012328 (tol = 0.002, component 1)

Mixed model did not converge, use glm:

## 
## Call:
## glm(formula = gma ~ land_use * year_ct + cos_td_rad + sin_td_rad + 
##     site, family = Gamma, data = P.anal)
## 
## Deviance Residuals: 
##      Min        1Q    Median        3Q       Max  
## -0.95553  -0.28198  -0.07873   0.15650   1.16860  
## 
## Coefficients:
##                                       Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                          0.3840219  0.1001764   3.833   0.0002 ***
## land_useBedouin Agriculture         -0.0842592  0.0824937  -1.021   0.3091    
## land_useKKL Plantings                0.0001899  0.0583558   0.003   0.9974    
## year_ct                             -0.0089596  0.0088011  -1.018   0.3107    
## cos_td_rad                          -0.0206125  0.0613463  -0.336   0.7374    
## sin_td_rad                           0.0954936  0.0531921   1.795   0.0750 .  
## siteGivot Bar                       -0.0780948  0.0546019  -1.430   0.1552    
## siteGivot Goral                      0.0075556  0.0627164   0.120   0.9043    
## siteHatzerim Base                   -0.0337372  0.0918198  -0.367   0.7139    
## siteMishmar Hanegev                 -0.0260323  0.0584789  -0.445   0.6570    
## siteNahal Ashan                      0.0940335  0.0822483   1.143   0.2551    
## siteNevatim Base                     0.0066576  0.1716479   0.039   0.9691    
## sitePark Loess                       0.0131366  0.0860731   0.153   0.8789    
## siteSayeret Shaked                   0.0386733  0.0779441   0.496   0.6207    
## land_useBedouin Agriculture:year_ct  0.0276513  0.0126212   2.191   0.0303 *  
## land_useKKL Plantings:year_ct        0.0285655  0.0124291   2.298   0.0232 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for Gamma family taken to be 0.1956952)
## 
##     Null deviance: 28.575  on 139  degrees of freedom
## Residual deviance: 21.703  on 124  degrees of freedom
## AIC: 445.98
## 
## Number of Fisher Scoring iterations: 5

perform stepwise model selection of Gaussian model.

## Start:  AIC=445.98
## gma ~ land_use * year_ct + cos_td_rad + sin_td_rad + site
## 
##                    Df Deviance    AIC
## - site              8   23.307 438.18
## - cos_td_rad        1   21.725 444.09
## <none>                  21.703 445.98
## - sin_td_rad        1   22.370 447.39
## - land_use:year_ct  2   23.147 449.36
## 
## Step:  AIC=440.23
## gma ~ land_use + year_ct + cos_td_rad + sin_td_rad + land_use:year_ct
## 
##                    Df Deviance    AIC
## - cos_td_rad        1   23.479 439.08
## <none>                  23.307 440.23
## - sin_td_rad        1   24.148 442.36
## - land_use:year_ct  2   24.632 442.74
## 
## Step:  AIC=439.29
## gma ~ land_use + year_ct + sin_td_rad + land_use:year_ct
## 
##                    Df Deviance    AIC
## <none>                  23.479 439.29
## - sin_td_rad        1   24.167 440.64
## - land_use:year_ct  2   24.952 442.45

keep removing terms, because \(\Delta AIC<2\). remove sine.

## Single term deletions
## 
## Model:
## gma ~ land_use * year_ct
##                  Df Deviance    AIC
## <none>                24.167 441.45
## land_use:year_ct  2   25.657 444.51

year X land use remain. This is the final model:

## 
## Call:
## glm(formula = gma ~ land_use * year_ct, family = Gamma, data = P.anal)
## 
## Deviance Residuals: 
##     Min       1Q   Median       3Q      Max  
## -0.9292  -0.3539  -0.1036   0.1449   1.2127  
## 
## Coefficients:
##                                      Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                          0.380616   0.036636  10.389   <2e-16 ***
## land_useBedouin Agriculture         -0.137185   0.062042  -2.211   0.0287 *  
## land_useKKL Plantings               -0.013240   0.058533  -0.226   0.8214    
## year_ct                             -0.013438   0.007054  -1.905   0.0589 .  
## land_useBedouin Agriculture:year_ct  0.024062   0.011716   2.054   0.0419 *  
## land_useKKL Plantings:year_ct        0.028566   0.012488   2.288   0.0237 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for Gamma family taken to be 0.2111039)
## 
##     Null deviance: 28.575  on 139  degrees of freedom
## Residual deviance: 24.167  on 134  degrees of freedom
## AIC: 441.45
## 
## Number of Fisher Scoring iterations: 5

Observations 140
Dependent variable gma
Type Generalized linear model
Family Gamma
Link inverse
χ²(5) 4.408
Pseudo-R² (Cragg-Uhler) 0.165
Pseudo-R² (McFadden) 0.054
AIC 441.450
BIC 462.041
Est. S.E. t val. p
(Intercept) 0.381 0.037 10.389 0.000
land_useBedouin Agriculture -0.137 0.062 -2.211 0.029
land_useKKL Plantings -0.013 0.059 -0.226 0.821
year_ct -0.013 0.007 -1.905 0.059
land_useBedouin Agriculture:year_ct 0.024 0.012 2.054 0.042
land_useKKL Plantings:year_ct 0.029 0.012 2.288 0.024
Standard errors: MLE

According to the model, no significant temporal trend for Loess, but interaction of year and land use is significant. Test whether temporal trends are significantly different from zero, using emmeans package, FDR correction for multiple comparisons.

##  land_use            year_ct.trend      SE  df t.ratio p.value
##  Loess                     -0.0134 0.00705 134  -1.905  0.1768
##  Bedouin Agriculture        0.0106 0.00935 134   1.136  0.2581
##  KKL Plantings              0.0151 0.01030 134   1.468  0.2166
## 
## P value adjustment: fdr method for 3 tests

No significant temporal trend detected for all three land uses. In view of this, re-fit model without interaction term.

## Start:  AIC=446.07
## gma ~ land_use + year_ct
## 
##            Df Deviance    AIC
## - year_ct   1   25.657 444.07
## <none>          25.657 446.07
## - land_use  2   28.526 454.73
## 
## Step:  AIC=444.07
## gma ~ land_use
## 
##            Df Deviance    AIC
## <none>          25.657 444.07
## - land_use  2   28.575 453.04

only land use remains.

## 
## Call:
## glm(formula = gma ~ land_use, family = Gamma, data = P.anal)
## 
## Deviance Residuals: 
##     Min       1Q   Median       3Q      Max  
## -0.8448  -0.3748  -0.1082   0.1509   1.3829  
## 
## Coefficients:
##                             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  0.32831    0.02181  15.056   <2e-16 ***
## land_useBedouin Agriculture -0.03117    0.03045  -1.024   0.3078    
## land_useKKL Plantings        0.09527    0.03705   2.571   0.0112 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for Gamma family taken to be 0.2249982)
## 
##     Null deviance: 28.575  on 139  degrees of freedom
## Residual deviance: 25.657  on 137  degrees of freedom
## AIC: 444.07
## 
## Number of Fisher Scoring iterations: 5

Observations 140
Dependent variable gma
Type Generalized linear model
Family Gamma
Link inverse
χ²(2) 2.918
Pseudo-R² (Cragg-Uhler) 0.110
Pseudo-R² (McFadden) 0.034
AIC 444.071
BIC 455.837
Est. S.E. t val. p
(Intercept) 0.328 0.022 15.056 0.000
land_useBedouin Agriculture -0.031 0.030 -1.024 0.308
land_useKKL Plantings 0.095 0.037 2.571 0.011
Standard errors: MLE

Test for pairwise differences among levels of land use, apply FDR correction for multiple comparisons.

##  contrast                            estimate     SE  df t.ratio p.value
##  Loess - Bedouin Agriculture           0.0312 0.0304 137   1.024  0.3078
##  Loess - KKL Plantings                -0.0953 0.0370 137  -2.571  0.0168
##  Bedouin Agriculture - KKL Plantings  -0.1264 0.0367 137  -3.443  0.0023
## 
## Note: contrasts are still on the inverse scale 
## P value adjustment: fdr method for 3 tests

No significant difference in GMA between Loess (3.0458883) and Bedouin agriculture (3.3653697). KKL Plantings (2.3608274) significantly lower than Loess (P=0.017) and Bedouin agriculture (P=0.002).

No significant temporal trend detected for all three land uses.

abundance

Explore data

## [1] "ABUNDANCE WITHOUT RARE SPECIES"
## [1] "data with 2012"

## [1] "data without 2012"

## [1] "data with 2012"

## [1] "data without 2012"
abundance year_ct site land_use td_sc cos_td_rad sin_td_rad
Min. : 2.00 Min. :0.000 Sayeret Shaked :30 Loess :51 Min. :-1.5653 Min. :0.02295 Min. :-0.9997
1st Qu.: 7.00 1st Qu.:2.000 Nahal Ashan :24 Bedouin Agriculture:44 1st Qu.:-0.7244 1st Qu.:0.34157 1st Qu.:-0.9201
Median : 10.00 Median :4.000 Mishmar Hanegev:23 KKL Plantings :45 Median : 0.6826 Median :0.85208 Median :-0.5087
Mean : 16.34 Mean :4.214 Givot Goral :15 NA Mean : 0.6387 Mean :0.67279 Mean :-0.4482
3rd Qu.: 17.25 3rd Qu.:6.000 Eshel Hanasi :12 NA 3rd Qu.: 1.5220 3rd Qu.:0.90882 3rd Qu.:-0.1543
Max. :125.00 Max. :8.000 Givot Bar :12 NA Max. : 4.9558 Max. :1.00000 Max. : 0.9845
NA NA (Other) :24 NA NA NA NA

outlier in loess with total abundance >30. outlier in bedouin agriculture with total abundance >120. Examine:

##                                         unit subunit        site year year_ct
## 1: Loess Covered Areas in the Northern Negev    <NA> Nahal Ashan 2020       8
##    settlements agriculture habitat dunes land_use          point_name
## 1:        <NA>        <NA>    <NA>  <NA>    Loess Nahal Ashan Loess 2
##                   date            datetime    td_sc    td_rad cos_td_rad
## 1: 2020-03-25 02:00:00 2020-03-25 09:25:40 -1.48902 -1.513416  0.0573492
##    sin_td_rad timediff_Jun21 monitors_name wind precipitation temperature
## 1: -0.9983542 -87.91667 days  Eyal Shochat <NA>          <NA>        <NA>
##    clouds h_from_sunrise  cos_hsun  sin_hsun pilot richness abundance      gma
## 1:   <NA>      1.7 hours 0.9025853 0.4305111 FALSE        5        38 4.967254
##                                         unit subunit      site year year_ct
## 1: Loess Covered Areas in the Northern Negev    <NA> Givot Bar 2018       6
##    settlements agriculture habitat dunes            land_use
## 1:        <NA>        <NA>    <NA>  <NA> Bedouin Agriculture
##                         point_name       date            datetime     td_sc
## 1: Givot Bar Bedouin Agriculture 2 2018-05-22 2018-05-22 05:21:00 0.6825762
##        td_rad cos_td_rad sin_td_rad timediff_Jun21 monitors_name wind
## 1: -0.5336404   0.860961 -0.5086709       -31 days          <NA> <NA>
##    precipitation temperature clouds h_from_sunrise cos_hsun   sin_hsun pilot
## 1:          <NA>        <NA>   <NA>    -0.42 hours 0.993961 -0.1097343 FALSE
##    richness abundance      gma
## 1:        7       125 5.011216

PHI>1, hence choose negative binomial. Fit fixed and mixed models. Choose mixed model if possible, otherwise choose a model with fixed-effects only.

mixed model converged.

## Generalized linear mixed model fit by maximum likelihood (Laplace
##   Approximation) [glmerMod]
##  Family: Negative Binomial(3.4767)  ( log )
## Formula: abundance ~ land_use * year_ct + cos_td_rad + sin_td_rad + (1 |  
##     site)
##    Data: P.anal
## 
##      AIC      BIC   logLik deviance df.resid 
##    988.2   1017.7   -484.1    968.2      130 
## 
## Scaled residuals: 
##     Min      1Q  Median      3Q     Max 
## -1.5959 -0.6310 -0.2227  0.3360  4.2385 
## 
## Random effects:
##  Groups Name        Variance Std.Dev.
##  site   (Intercept) 0.09997  0.3162  
## Number of obs: 140, groups:  site, 9
## 
## Fixed effects:
##                                     Estimate Std. Error z value Pr(>|z|)    
## (Intercept)                          1.65536    0.25985   6.370 1.89e-10 ***
## land_useBedouin Agriculture          0.33579    0.33255   1.010 0.312618    
## land_useKKL Plantings                0.89990    0.22217   4.051 5.11e-05 ***
## year_ct                              0.04737    0.03845   1.232 0.217957    
## cos_td_rad                           0.54866    0.21422   2.561 0.010432 *  
## sin_td_rad                          -0.35334    0.18317  -1.929 0.053730 .  
## land_useBedouin Agriculture:year_ct  0.03225    0.05364   0.601 0.547673    
## land_useKKL Plantings:year_ct       -0.15429    0.04505  -3.425 0.000615 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Correlation of Fixed Effects:
##             (Intr) lnd_BA ln_KKLP yer_ct cs_td_ sn_td_ l_BA:_
## lnd_sBdnAgr -0.318                                           
## lnd_sKKLPln -0.290  0.402                                    
## year_ct     -0.489  0.250  0.416                             
## cos_td_rad  -0.679 -0.082 -0.176   0.155                     
## sin_td_rad   0.117  0.046  0.157   0.389 -0.281              
## lnd_sBAgr:_  0.225 -0.728 -0.281  -0.504  0.053  0.068       
## lnd_sKKLP:_  0.198 -0.202 -0.737  -0.575  0.119 -0.065  0.408
## $site
##                  (Intercept)
## Eshel Hanasi    -0.045137191
## Givot Bar        0.002827638
## Givot Goral      0.106788644
## Hatzerim Base   -0.001968742
## Mishmar Hanegev  0.075006970
## Nahal Ashan      0.065199853
## Nevatim Base     0.005947562
## Park Loess      -0.093317558
## Sayeret Shaked  -0.103992836
## 
## with conditional variances for "site"
## $site

Perform stepwise model selection of mixed model.

## Warning in checkConv(attr(opt, "derivs"), opt$par, ctrl = control$checkConv, :
## Model failed to converge with max|grad| = 0.00226083 (tol = 0.002, component 1)
## Single term deletions
## 
## Model:
## abundance ~ land_use * year_ct + cos_td_rad + sin_td_rad + (1 | 
##     site)
##                  npar     AIC
## <none>                 988.24
## cos_td_rad          1  992.69
## sin_td_rad          1  989.96
## land_use:year_ct    2 1000.85

drop sine of time of year because \(\Delta AIC<2\)

## Warning in checkConv(attr(opt, "derivs"), opt$par, ctrl = control$checkConv, :
## Model failed to converge with max|grad| = 0.00233194 (tol = 0.002, component 1)
## Single term deletions
## 
## Model:
## abundance ~ land_use * year_ct + cos_td_rad + (1 | site)
##                  npar     AIC
## <none>                 989.89
## cos_td_rad          1  992.00
## land_use:year_ct    2 1003.97

land use * year and sampling time of year remain. The final model:

## Generalized linear mixed model fit by maximum likelihood (Laplace
##   Approximation) [glmerMod]
##  Family: Negative Binomial(3.3486)  ( log )
## Formula: abundance ~ land_use * year_ct + cos_td_rad + (1 | site)
##    Data: P.anal
## 
##      AIC      BIC   logLik deviance df.resid 
##    989.9   1016.4   -485.9    971.9      131 
## 
## Scaled residuals: 
##     Min      1Q  Median      3Q     Max 
## -1.5846 -0.6191 -0.2535  0.3014  4.1904 
## 
## Random effects:
##  Groups Name        Variance Std.Dev.
##  site   (Intercept) 0.09622  0.3102  
## Number of obs: 140, groups:  site, 9
## 
## Fixed effects:
##                                     Estimate Std. Error z value Pr(>|z|)    
## (Intercept)                          1.72151    0.26502   6.496 8.26e-11 ***
## land_useBedouin Agriculture          0.36259    0.34336   1.056 0.290957    
## land_useKKL Plantings                0.96686    0.22215   4.352 1.35e-05 ***
## year_ct                              0.07640    0.03586   2.131 0.033124 *  
## cos_td_rad                           0.42973    0.21112   2.035 0.041805 *  
## land_useBedouin Agriculture:year_ct  0.03816    0.05468   0.698 0.485223    
## land_useKKL Plantings:year_ct       -0.16047    0.04539  -3.536 0.000407 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Correlation of Fixed Effects:
##             (Intr) lnd_BA ln_KKLP yer_ct cs_td_ l_BA:_
## lnd_sBdnAgr -0.349                                    
## lnd_sKKLPln -0.324  0.402                             
## year_ct     -0.608  0.286  0.399                      
## cos_td_rad  -0.696 -0.034 -0.117   0.320              
## lnd_sBAgr:_  0.234 -0.751 -0.300  -0.572  0.058       
## lnd_sKKLP:_  0.209 -0.202 -0.738  -0.590  0.100  0.407
## $site
##                 (Intercept)
## Eshel Hanasi    -0.22869398
## Givot Bar        0.56150117
## Givot Goral      0.08251180
## Hatzerim Base   -0.16121909
## Mishmar Hanegev  0.33649321
## Nahal Ashan     -0.00925356
## Nevatim Base    -0.06818663
## Park Loess      -0.20895200
## Sayeret Shaked  -0.28722925
## 
## with conditional variances for "site"
## $site

Not the greatest fit in the world. Take into account when stressing the strength of the results.

Interpretation of abundance model:

Observations 140
Dependent variable abundance
Type Mixed effects generalized linear model
Family Negative Binomial(3.3486)
Link log
AIC 989.895
BIC 1016.369
Pseudo-R² (fixed effects) 0.486
Pseudo-R² (total) 0.782
Fixed Effects
Est. S.E. z val. p
(Intercept) 1.722 0.265 6.496 0.000
land_useBedouin Agriculture 0.363 0.343 1.056 0.291
land_useKKL Plantings 0.967 0.222 4.352 0.000
year_ct 0.076 0.036 2.131 0.033
cos_td_rad 0.430 0.211 2.035 0.042
land_useBedouin Agriculture:year_ct 0.038 0.055 0.698 0.485
land_useKKL Plantings:year_ct -0.160 0.045 -3.536 0.000
Random Effects
Group Parameter Std. Dev.
site (Intercept) 0.310
Grouping Variables
Group # groups ICC
site 9 0.168

all model effects are significant. Test for difference of temporal trend from zero for each land use.

##  land_use            year_ct.trend     SE  df z.ratio p.value
##  Loess                      0.0764 0.0359 Inf   2.131  0.0331
##  Bedouin Agriculture        0.1146 0.0451 Inf   2.542  0.0331
##  KKL Plantings             -0.0841 0.0378 Inf  -2.226  0.0331
## 
## P value adjustment: fdr method for 3 tests

All trends are significantly different from zero.

Test for pairwise differences in average abundance among levels of land use, apply FDR correction for multiple comparisons.

##  contrast                            year_ct estimate    SE  df z.ratio p.value
##  Loess - Bedouin Agriculture            4.21   -0.523 0.228 Inf  -2.292  0.0657
##  Loess - KKL Plantings                  4.21   -0.291 0.152 Inf  -1.907  0.0849
##  Bedouin Agriculture - KKL Plantings    4.21    0.233 0.188 Inf   1.238  0.2155
## 
## Results are given on the log (not the response) scale. 
## P value adjustment: fdr method for 3 tests

No significant difference in average abundance among the three land uses - Loess (10.3047081), Bedouin agriculture (17.3922753) and KKL Plantings (13.7794718).

All trends are significantly different from zero (P=0.033 for all three). The rates are as follows: KKL plantings decreases 8.0635856% per year; Loess and Bedouin agriculture increase 7.939393% and 12.1383509% per year, respectively.

community analysis using package MVabund

Explore single species observations, including mean-variance plot. There is a strong mean-var relationship, indicating that employing GLMs is the proper way to analyze, rather than OLS (assumption of homogeneity is violated).

## Overlapping points were shifted along the y-axis to make them visible.
## 
##  PIPING TO 2nd MVFACTOR
## Only the variables Galerida.cristata, Passer.domesticus, Columba.livia, Streptopelia.decaocto, Prinia.gracilis, Lanius.excubitor, Corvus.cornix, Burhinus.oedicnemus, Chloris.chloris, Spilopelia.senegalensis, Acridotheres.tristis, Falco.tinnunculus were included in the plot 
## (the variables with highest total abundance).

## [1] "abundance observations, aggregated into plots and species (i.e., several observations from the same species in the same plot are aggregated):"

## [1] "these are the actual observations, before aggregation into plots:"

## [1] "zoom in on high abundance observations:"

start model specification:

##       nb       po 
## 227.5317 318.7130
## [1] "POISSON"

## [1] "NEGATIVE BINOMIAL"

negative binomial model is better than poisson according to residuals and AIC comparison.

##       nb       po      nb1 
## 227.5317 318.7130 227.6228

The addition of the explanatory variable ‘site’ is not improving the AIC of the model. stepwise selection of model:

## Single term deletions
## 
## Model:
## spp_no_rare ~ land_use * year_ct + cos_td_rad + sin_td_rad
##                  Df    AIC
## <none>              3868.0
## cos_td_rad       17 3913.9
## sin_td_rad       17 3871.3
## land_use:year_ct 34 3892.2

close call for sine. when included in the final model comes out borderline, P=0.05. remove.

## Single term deletions
## 
## Model:
## spp_no_rare ~ land_use * year_ct + cos_td_rad
##                  Df    AIC
## <none>              3871.3
## cos_td_rad       17 3897.0
## land_use:year_ct 34 3891.6

final model includes land use * year, sampling time of year.

## 
## Test statistics:
##                                     wald value Pr(>wald)    
## (Intercept)                             11.318     0.001 ***
## land_useBedouin Agriculture              5.697     0.001 ***
## land_useKKL Plantings                    8.128     0.001 ***
## year_ct                                  6.616     0.001 ***
## cos_td_rad                               7.148     0.001 ***
## land_useBedouin Agriculture:year_ct      3.231     0.365    
## land_useKKL Plantings:year_ct            6.670     0.001 ***
## --- 
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 
## 
## Test statistic:  16.33, p-value: 0.001 
## Arguments:
##  Test statistics calculated assuming response assumed to be uncorrelated 
##  P-value calculated using 999 resampling iterations via pit.trap resampling (to account for correlation in testing).
## Analysis of Deviance Table
## 
## Model: spp_no_rare ~ land_use * year_ct + cos_td_rad
## 
## Multivariate test:
##                  Res.Df Df.diff    Dev Pr(>Dev)   
## (Intercept)         139                           
## land_use            137       2 246.61     0.01 **
## year_ct             136       1  48.13     0.01 **
## cos_td_rad          135       1  47.55     0.01 **
## land_use:year_ct    133       2  88.35     0.01 **
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Univariate Tests:
##                  Acridotheres.tristis          Burhinus.oedicnemus         
##                                   Dev Pr(>Dev)                 Dev Pr(>Dev)
## (Intercept)                                                                
## land_use                        5.752     0.33               6.596     0.23
## year_ct                        12.957     0.01               0.219     1.00
## cos_td_rad                          0     1.00              15.536     0.02
## land_use:year_ct                 2.76     0.90              14.101     0.03
##                  Chloris.chloris          Columba.livia          Corvus.cornix
##                              Dev Pr(>Dev)           Dev Pr(>Dev)           Dev
## (Intercept)                                                                   
## land_use                   4.174     0.44        13.207     0.03         5.238
## year_ct                    0.414     1.00         0.354     1.00         0.331
## cos_td_rad                 0.219     1.00         0.078     1.00         0.113
## land_use:year_ct           2.824     0.90        15.761     0.02         1.046
##                           Falco.tinnunculus          Galerida.cristata         
##                  Pr(>Dev)               Dev Pr(>Dev)               Dev Pr(>Dev)
## (Intercept)                                                                    
## land_use             0.33             1.984     0.72            12.595     0.03
## year_ct              1.00             3.545     0.69             2.399     0.87
## cos_td_rad           1.00             3.665     0.60             4.986     0.39
## land_use:year_ct     0.97             0.695     0.97             3.698     0.76
##                  Iduna.pallida          Lanius.excubitor         
##                            Dev Pr(>Dev)              Dev Pr(>Dev)
## (Intercept)                                                      
## land_use                27.694     0.01           34.644     0.01
## year_ct                  0.014     1.00            0.015     1.00
## cos_td_rad               1.292     0.98            0.283     1.00
## land_use:year_ct             0     0.97            3.911     0.71
##                  Passer.domesticus          Prinia.gracilis         
##                                Dev Pr(>Dev)             Dev Pr(>Dev)
## (Intercept)                                                         
## land_use                    29.549     0.01           1.698     0.72
## year_ct                      2.472     0.87           1.002     0.99
## cos_td_rad                   3.581     0.62            0.35     1.00
## land_use:year_ct            17.406     0.02            4.83     0.62
##                  Pycnonotus.xanthopygos          Spilopelia.senegalensis
##                                     Dev Pr(>Dev)                     Dev
## (Intercept)                                                             
## land_use                         13.186     0.03                  20.893
## year_ct                           0.091     1.00                   0.113
## cos_td_rad                        0.619     1.00                   3.265
## land_use:year_ct                  7.731     0.26                   0.214
##                           Streptopelia.decaocto          Streptopelia.turtur
##                  Pr(>Dev)                   Dev Pr(>Dev)                 Dev
## (Intercept)                                                                 
## land_use             0.01                40.218     0.01               0.511
## year_ct              1.00                13.932     0.01               6.625
## cos_td_rad           0.69                 0.583     1.00               5.012
## land_use:year_ct     0.97                 2.149     0.90               5.806
##                           Upupa.epops          Vanellus.spinosus         
##                  Pr(>Dev)         Dev Pr(>Dev)               Dev Pr(>Dev)
## (Intercept)                                                              
## land_use             0.84      10.642     0.03            18.028     0.01
## year_ct              0.17       1.411     0.97             2.235     0.87
## cos_td_rad           0.39       0.279     1.00             7.688     0.18
## land_use:year_ct     0.54       1.122     0.96             4.293     0.68
## Arguments:
##  Test statistics calculated assuming uncorrelated response (for faster computation) 
## P-value calculated using 99 iterations via PIT-trap resampling.

All factors (land_use, year, land_use:year, time of year) have a statistically significant effect on community composition.

The interaction land use * year is significantly different from Loess only for KKL plantings, not for Bedouin agriculture. In addition, this term is only significant for 3 species: stone curlew, rock pigeon and house sparrow. Therefore, plot species - level model for these 3 species which includes the interaction, and re-run manyglm without interaction to simplify interpretation.

## Resampling begins for test 1.
##  Resampling run 0 finished. Time elapsed: 0.00 minutes...
## Resampling begins for test 2.
##  Resampling run 0 finished. Time elapsed: 0.00 minutes...
## Resampling begins for test 3.
##  Resampling run 0 finished. Time elapsed: 0.00 minutes...
## Time elapsed: 0 hr 0 min 9 sec
## 
## Test statistics:
##                             wald value Pr(>wald)    
## (Intercept)                     11.726     0.001 ***
## land_useBedouin Agriculture      9.586     0.001 ***
## land_useKKL Plantings           10.209     0.001 ***
## year_ct                          7.001     0.001 ***
## cos_td_rad                       6.012     0.024 *  
## --- 
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 
## 
## Test statistic:  15.03, p-value: 0.001 
## Arguments:
##  Test statistics calculated assuming response assumed to be uncorrelated 
##  P-value calculated using 999 resampling iterations via pit.trap resampling (to account for correlation in testing).
## Analysis of Deviance Table
## 
## Model: spp_no_rare ~ land_use + year_ct + cos_td_rad
## 
## Multivariate test:
##             Res.Df Df.diff    Dev Pr(>Dev)   
## (Intercept)    139                           
## land_use       137       2 246.61     0.01 **
## year_ct        136       1  48.13     0.01 **
## cos_td_rad     135       1  47.55     0.01 **
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Univariate Tests:
##             Acridotheres.tristis          Burhinus.oedicnemus         
##                              Dev Pr(>Dev)                 Dev Pr(>Dev)
## (Intercept)                                                           
## land_use                   5.752     0.32               6.596     0.22
## year_ct                   12.957     0.01               0.219     1.00
## cos_td_rad                     0     1.00              15.536     0.01
##             Chloris.chloris          Columba.livia          Corvus.cornix
##                         Dev Pr(>Dev)           Dev Pr(>Dev)           Dev
## (Intercept)                                                              
## land_use              4.174     0.40        13.207     0.03         5.238
## year_ct               0.414     0.99         0.354     1.00         0.331
## cos_td_rad            0.219     1.00         0.078     1.00         0.113
##                      Falco.tinnunculus          Galerida.cristata         
##             Pr(>Dev)               Dev Pr(>Dev)               Dev Pr(>Dev)
## (Intercept)                                                               
## land_use        0.33             1.984     0.70            12.595     0.03
## year_ct         1.00             3.545     0.63             2.399     0.83
## cos_td_rad      1.00             3.665     0.76             4.986     0.50
##             Iduna.pallida          Lanius.excubitor          Passer.domesticus
##                       Dev Pr(>Dev)              Dev Pr(>Dev)               Dev
## (Intercept)                                                                   
## land_use           27.694     0.01           34.644     0.01            29.549
## year_ct             0.014     1.00            0.015     1.00             2.472
## cos_td_rad          1.292     0.98            0.283     1.00             3.581
##                      Prinia.gracilis          Pycnonotus.xanthopygos         
##             Pr(>Dev)             Dev Pr(>Dev)                    Dev Pr(>Dev)
## (Intercept)                                                                  
## land_use        0.01           1.698     0.70                 13.186     0.03
## year_ct         0.83           1.002     0.98                  0.091     1.00
## cos_td_rad      0.76            0.35     1.00                  0.619     1.00
##             Spilopelia.senegalensis          Streptopelia.decaocto         
##                                 Dev Pr(>Dev)                   Dev Pr(>Dev)
## (Intercept)                                                                
## land_use                     20.893     0.01                40.218     0.01
## year_ct                       0.113     1.00                13.932     0.01
## cos_td_rad                    3.265     0.76                 0.583     1.00
##             Streptopelia.turtur          Upupa.epops          Vanellus.spinosus
##                             Dev Pr(>Dev)         Dev Pr(>Dev)               Dev
## (Intercept)                                                                    
## land_use                  0.511     0.79      10.642     0.03            18.028
## year_ct                   6.625     0.18       1.411     0.94             2.235
## cos_td_rad                5.012     0.49       0.279     1.00             7.688
##                     
##             Pr(>Dev)
## (Intercept)         
## land_use        0.01
## year_ct         0.83
## cos_td_rad      0.16
## Arguments:
##  Test statistics calculated assuming uncorrelated response (for faster computation) 
## P-value calculated using 99 iterations via PIT-trap resampling.
## Warning: Using `size` aesthetic for lines was deprecated in ggplot2 3.4.0.
## ℹ Please use `linewidth` instead.
## This warning is displayed once every 8 hours.
## Call `lifecycle::last_lifecycle_warnings()` to see where this warning was
## generated.
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Significant negative temporal effect on house sparrow and positive effect on common myna. Significant effect land use: most species do not prefer natural loess over the other two habitats. Nonetheless, batha specialist species are not detected in our survey: is it possible they have disappeared?

check general trend in species that were filtered due to rareness in dataset.

Of the 24 species that did not make the rare species cutoff, 9 (38%) appeared only in the natural loess vs. only 3 (12%) in KKL plantings and 2 (8%) in the Bedouin agriculture. Of these 9 species, 9 are defined as batha specialists, vs. 1 and 0 in Bedouin agriculture, respectively. Moreover, of the 9 species unique to the natural loess, 7 are endangered vs. 0 in KKL plantings and 0 in Bedouin agriculture, respectively.